Question 1
Edited: Aug 17, 2018
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This patient has a long history of lesions on the face and back (see Figure).
Figure.
They occasionally drain pus. He does not have a history of steroid use. Which of the following is
the most likely diagnosis?

rosacea


steroid-induced

acne

furunculosis


acne

vulgaris

lupus

erythematosus
Educational Objective:
Recognize the manifestations of acne vulgaris.
Key Point:
Acne vulgaris is characterized by comedones, inflammatory papules, and pustules.
Explanation:
This patient has acne vulgaris, characterized by comedones, inflammatory papules, and
pustules. Acne is not primarily an infectious skin disease, but rather is an inflammatory
condition associated with sebaceous follicles, which are a specialized type of hair follicle on the
face, chest, and back.
Rosacea is typically characterized by erythematous telangiectasias, papules/pustules, and
phymas. This patient’s rash is not consistent with this diagnosis.
A furuncle is characterized by a painful, suppurative inflammatory nodule at the site of a hair
follicle but is not associated with the comedones present in this case, making the diagnosis of
furunculosis less likely.
Steroid-induced acne is less likely, because this patient does not have any history of steroid use.
This type of acne is characterized by a monomorphous, inflammatory papular rash distinct from
the polymorphous inflammatory papular appearance of acne vulgaris.
The classic rash associated with acute cutaneous lupus is described as an erythematous rash
involving the cheeks and the bridge of the nose but sparing the nasolabial folds. This patient’s
rash is not consistent with acute cutaneous lupus.
References:
Dahl M. Rosacea: pathogenesis, clinical features, and diagnosis. Revised January 23, 2017.
Accessed June 7, 2017.
Downey K. Technique of incision and drainage for skin abscess. Revised May 16, 2017. Accessed
June 7, 2017.
Merola J, Moschella S. Overview of cutaneous lupus erythematosus. Revised March 24, 2017.
Accessed June 7, 2017.
Thiboutot D, Zaenglein A. Pathogenesis, clinical manifestations, and diagnosis of acne
vulgaris. Revised August 23, 2016. Accessed June 7, 2017.
Question 2
Edited: Aug 17, 2018
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When a patient presents with an acute onset of an acneiform eruption atypical for acne vulgaris
or rosacea, other causes should be considered. Which of the following is not known to cause
acneiform eruptions?

androgenic

or anabolic steroids

corticosteroids


bromides

and iodides

oral
 contraceptives

hydrochlorothiazide


polycystic

ovarian disease (Stein-Leventhal syndrome)
Educational Objective:
Identify medicines that, when used, can cause acneiform eruptions.
Key Point:
Many different classes of medications and certain medical conditions (eg, polycystic ovarian
disease) can be associated with acneiform eruptions.
Explanation:
The etiologies of drug- and hormone-induced acne are unknown, but they are presumed similar
to that of acne vulgaris, which is associated with increased pilosebaceous responsiveness to
endogenous androgenic steroids.
With acute drug-induced eruptions, all lesions appear at about the same time and tend to be in
the same stage of development. As with systemic corticosteroid administration, lesions are
diffusely distributed, favoring the chest, back, and shoulders.
With long-term steroid administration or excess endogenous steroid production (eg, Cushing
syndrome, polycystic ovarian disease), other manifestations of steroid excess or associated
hormonal derangement may be present (eg, amenorrhea, infertility, weakness, weight gain,
hirsutism, hypertension, cutaneous striae, easy bruisability, obesity with "moon facies,"
"buffalo hump").
References:
Samuel AD, Chu C-Y. Drug eruptions. Revised October 3, 2016. Accessed June 7, 2017.
Thiboutot D, Zaenglein A. Pathogenesis, clinical manifestations, and diagnosis of acne
vulgaris. Revised August 23, 2016. Accessed June 7, 2017.
Question 3
Edited: Aug 17, 2018
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A patient who received a kidney transplant several years ago was recently admitted to the
hospital for worsening renal function. He was given increasing doses of prednisone and
cyclosporine. Following their administration, he developed skin lesions on his chest and arms
(see Figure).
Figure.
Routine bacterial and fungal cultures are negative. Which of the following is the most likely
diagnosis?

steroid-induced

acne

staphylococcal

sepsis

candida

sepsis

varicella

(chicken pox)

acne

vulgaris
Educational Objective:
Review the differential diagnosis of an acneiform eruption in a patient with a suppressed
immune system.
Key Point:
It is important to perform cultures of pustular rash in an immunocompromised patient to rule
out an infectious etiology. Steroid-induced acne is diagnosed once infection is excluded.
Explanation:
This patient has multiple erythematous papules and pustules over the chest and arms without
comedones (blackheads and whiteheads). Any pustular eruption in an immunosuppressed
patient should trigger appropriate bacterial, candidal, and fungal cultures to be performed.
Steroid-induced acne cultures are sterile.
Disseminated Candida albicans infection resulting in sepsis can lead to small pustular lesions
similar in appearance to those shown in the Figure. A candidal infection is less likely in this case
because this patient does not have any signs of sepsis.
Rash associated with staphylococcal sepsis is typically described as erythematous and
maculopapular. The patient’s rash does not have that appearance.
Varicella is characterized by several days of fever, pharyngitis, and malaise followed by a
pruritic, vesicular rash that presents in crops over several days. This patient’s history and rash
are inconsistent with this diagnosis.
Acne vulgaris is characterized by the presence of comedones in the setting of erythematous
papules and pustules. There are no comedones present in this patient, making acne vulgaris
less likely.
References:
Albrecht MA. Clinical features of varicella zoster virus infection: chickenpox. Revised February 8,
2016. Accessed June 7, 2017.
Graber E. Treatment of acne vulgaris. Revised March 24, 2017. Accessed June 7, 2017.
Kauffman CA. Overview of Candida infections. Revised January 5, 2016. Accessed June 7, 2017.
Lopez FA, Sanders CV. Fever and rash in the immunocompetent patient. Revised September 13,
2016. Accessed June 7, 2017.
Question 4
Edited: Aug 17, 2018
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A 20-year-old man who is otherwise healthy presents to you for evaluation of a facial rash that
has been present for the past several weeks (see Figure).
Figure. Reproduced from PimplesPictures.
He notes no pain, pruritus, or bleeding, and he has not used any topical treatments for this
issue. He does not smoke cigarettes, drink alcohol, or use illicit substances. He does not take
any medications or have any known medication allergies.
His vital signs are: blood pressure 120/80 mm Hg, pulse 75 beats/minute, respiratory rate 16
breaths/minute, oxygen saturation 99% on room air, and temperature 99 °F.
What is the next step in the management of this patient's condition?

Start

topical tretinoin.

Start

metronidazole gel.

Start

hydrocortisone ointment.

Start

erythromycin ointment.
Educational Objective:
Recognize and manage noninflammatory acne vulgaris.
Key Point:
Topical tretinoin is first-line therapy for noninflammatory acne vulgaris, which is characterized
by comedones.
Explanation:
This patient has noninflammatory acne vulgaris, which is characterized by comedones.
Comedones form when sebaceous material blocks the hair follicle/sebaceous gland unit and are
described as either open or closed, depending on whether the follicle is open or closed at the
surface. Open comedones (blackheads) are black because of melanin. Closed comedones
(whiteheads) are white because they are closed at the surface. The Figure shows closed
comedones. First-line treatment would be topical tretinoin.
Although hydrocortisone ointment would be helpful for the treatment of contact dermatitis,
topical steroids do not have a role in the treatment of comedones. Metronidazole gel would be
an appropriate treatment if concern existed for rosacea, but it is not indicated for the
treatment of acne.
References:
Graber E. Treatment of acne vulgaris. Revised March 24, 2017. Accessed June 7, 2017.
PimplesPictures website. Accessed June 7, 2017.
Zaenglein AL, Pathy AL, Schlosser BJ, et al. Guidelines of care for the management of acne
vulgaris. J Am Acad Dermatol 2016;74(5):945-73.e33.
Question 5
Edited: Aug 17, 2018
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A 19-year-old man presents for evaluation of a facial rash that has been present for the past
several weeks (see Figure).
Figure. Reproduced from Health website.
He notes no pain, pruritus, or bleeding, and he says he has not used any topical medications for
the rash. He does not smoke cigarettes, drink alcohol, or use illicit substances. He does not take
any medications and has no known allergies. Vital signs are: blood pressure 120/80 mm Hg,
pulse 75 beats/minute, respiratory rate 16 breaths/minute, oxygen saturation 99% room air,
and temperature 99 °F.
What is the next step in the management of this patient's condition?

Initiate

therapy with topical tretinoin.

Initiate

therapy with hydrocortisone ointment.

Initiate

therapy with topical salicylic acid.

Initiate

therapy with oral isotretinoin.
Educational Objective:
Recognize and manage inflammatory acne vulgaris.
Key Point:
First-line medical therapy for inflammatory acne vulgaris is topical tretinoin.
Explanation:
This patient is presenting with inflammatory acne vulgaris, which is characterized by
inflammatory papules and pustules. First-line medical therapy for this patient would involve
treatment with topical tretinoin. Topical salicylic acid would be an appropriate adjunct or
second-line therapy. Oral isotretinoin would be an appropriate therapy for refractory nodular
acne. It is important to remember that oral isotretinoin has been associated with
teratogenicity, so female patients should be advised to avoid sexual activity while taking this
medication. A topical steroid such as hydrocortisone ointment does not have a role in the
treatment of inflammatory acne vulgaris.
References:
Graber E. Treatment of acne vulgaris. Revised March 24, 2017. Accessed June 7, 2017.
Healthh website. Accessed June 7, 2017.
Zaenglein AL, Pathy AL, Schlosser BJ, et al. Guidelines of care for the management of acne
vulgaris. J Am Acad Dermatol 2016;74(5):945-73.e33.
Question 6
Edited: Aug 17, 2018
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A 50-year-old woman with no significant past medical history presents to you for evaluation of
a facial rash that has been present for the past few months (see Figure).
Figure. Reproduced from Kern DW. What is rosacea?
She notes that the rash is not painful, pruritic, or bleeding. She has not used any new cosmetic
products, new soaps, or new detergents. She does not take any medications and does not have
any known allergies to medications. Her vital signs are: blood pressure 120/80 mm Hg, pulse 75
beats/minute, respiratory rate 14 breaths/minute, oxygen saturation 100% room air, and
temperature 99 °F.
What would be the first-line medication for treatment of this condition?

Initiate

therapy with topical benzoyl peroxide.

Initiate

therapy with topical salicylic acid.

Initiate

therapy with metronidazole gel.

Initiate

therapy with hydrocortisone ointment.
Educational Objective:
Recognize and manage papulopustular rosacea.
Key Point:
First-line medical therapy for a patient with papulopustular rosacea is topical metronidazole
gel.
Explanation:
The Figure shows papulopustular rosacea. Appropriate therapy for the treatment of this patient
with rosacea would be adequate sun protection, use of moisturizers, and to counsel the patient
to avoid triggers of flushing. First-line medication for the treatment of this condition is
metronidazole gel. Topical steroids are generally not used for the treatment of rosacea. Topical
benzoyl peroxide can be used if first-line therapy is ineffective. Topical salicylic acid is generally
not used for the treatment of rosacea.
References:
Dahl M. Rosacea: pathogenesis, clinical features, and diagnosis. Revised January 23, 2017.
Accessed June 7, 2017.
Kern DW. What is rosacea? Accessed June 7, 2017.
Maier LE. Management of rosacea. Revised April 25, 2017. Accessed June 7, 2017.
Question 1
Edited: Mar 4, 2017
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A 20-year-old woman received multiple cat bites on her forearm 2 weeks ago. She was treated
with systemic and topical antibiotics. Her condition initially improved, but then it began to
worsen 2 days later with increasing pruritus (see Figure).
Figure.
Several similar-appearing lesions are located elsewhere on her forearm.
Which of the following is the most likely diagnosis?

allergic

contact dermatitis

cat
 scratch disease

lichen

planus

cellulitis


herpes

simplex virus (HSV) infection
Educational Objective:
Recognize the presentation of contact dermatitis.
Key Point:
Grouped vesicles on a poorly demarcated plaque after topical antibiotic use likely indicates
contact dermatitis. Neomycin topical antibiotic is a common allergen.
Explanation:
This patient has a poorly demarcated plaque, with erythema, edema, and grouped vesicles. The
most appropriate diagnosis is allergic contact dermatitis, because the patient had likely used
neomycin antibiotic ointment, a common allergic contact offender, for a few days before these
typical features of contact dermatitis developed.
HSV infection presents with grouped vesicles on erythematous bases, often with a prodrome of
pain or discomfort. Cellulitis is erythematous, but it is usually not associated with multiple
vesicles and would be unlikely to develop in several locations simultaneously. In addition,
cellulitis is painful, not pruritic. Cat scratch disease typically begins with a primary papule,
vesicle, or pustule at the site of inoculation, with subsequent proximal lymphadenitis. Lichen
planus presents, most commonly, as a circular collection of papules with a characteristic bluishpurple color.
Reference:
Rakel RE, Rakel D. Textbook of Family Medicine. 8th ed., 2011.
Question 2
Edited: Mar 4, 2017
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A patient presents to you with central facial erythema and scaling prominent in the nasolabial
folds (see Figure).
Figure.
Which of the following is the most likely diagnosis?

rosacea


tinea

versicolor

seborrheic

dermatitis

discoid

lupus erythematosus

tinea

capitis
Educational Objective:
Recognize the presentation of seborrheic dermatitis.
Key Point:
Erythema with yellow-white scales is a characteristic feature of seborrheic dermatitis. Typical
facial sites include nasolabial folds and the eyebrow area.
Explanation:
This patient has poorly demarcated, slightly scaly red plaques in the nasolabial area of the face.
Although these manifestations resemble fungal infection in some regard, the condition this
patient has is actually seborrheic dermatitis, which usually occurs as yellow scale on the scalp,
but may involve the eyebrow, nasolabial, and postauricular areas.
In immunosuppressed patients or in those with Parkinson disease, seborrheic dermatitis may
appear more inflammatory and may be more recalcitrant to therapy.
Tinea versicolor and capitis are fungal infections. Tinea versicolor may present with
hypopigmented or hyperpigmented patches, but it rarely occurs on the face and often on the
chest and back. Tinea capitis presents with well-demarcated, scaly papules and plaques in the
scalp and hair area, and it is associated with alopecia.
Discoid lupus erythematosus also presents with well-demarcated, scaly erythematous plaques,
but scarring is often present. Patients with rosacea exhibit flushing and sensitivity of facial skin.
References:
Dahl MV. Approach to patient with facial erythema. Revised August 12, 2016. Accessed June 7,
2017.
Rakel RE, Rakel D. Textbook of Family Medicine. 8th ed., 2011.
Question 3
Edited: Mar 3, 2017
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A patient presents to you with an intensely pruritic recurrent vesicular eruption on the hands
(see Figure).
Figure.
It has been present for many years. Which of the following is the most likely diagnosis?

scabies


dyshidrotic

eczema

metal

allergy

fungal

infection

herpetic

whitlow
Educational Objective:
Discuss the key features of dyshidrotic eczema.
Key Point:
Recurrent pruritic vesicles limited to the hands or feet are key features of dyshidrotic eczema.
Explanation:
Dyshidrotic eczema presents as recurrent pruritic vesicles on the hands, feet, or both
extremities. Vesicles may be small or may coalesce to form larger bullae.
Scabies, herpes simplex virus (HSV) infection, and fungal infections can be vesicular, but they
are not generally limited to the hands. HSV infection presents as grouped vesicles on an
erythematous base, and it is more often painful than pruritic. Dermatophyte (fungal) infections
can be vesicular but are associated with well-demarcated, scaly plaques. Scabies is an intensely
pruritic eruption occurring as nonspecific excoriated papules, sometimes with linear burrows,
and more commonly vesicular in infants. There is no history of exposure to metal to
suggest allergy to metal.
Reference:
Adams DR, Marks JG Jr. Acute palmoplantar eczema (dyshidrotic eczema). Revised May 30,
2017. Accessed June 7, 2017.
Question 4
Edited: Mar 4, 2017
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A patient with very dry legs presents to you after having recently developed a rash (see Figure).
Figure.
Which of the following is the most likely diagnosis?

impetigo


lichen

planus

allergic

contact dermatitis

psoriasis


xerosis

with xerotic eczema
Educational Objective:
Recognize the presentation of xerotic eczema.
Key Point:
A scaly rash on the legs and a history of dryness are key features of xerotic eczema.
Explanation:
This patient has significant inflammation as a direct result of dryness (xerosis). Impetigo is not
as scaly and presents with golden-colored bullae or crusty lesions. Psoriasis has more sharply
demarcated plaques. Lichen planus occurs on the legs but generally manifests as thickened skin
rather than scales. The absence of a history of a contactant makes contact dermatitis less likely.
References:
Fazio SB, Yosipovitch G. Pruritus: etiology and patient evaluation. Revised September 23, 2016.
Accessed June 7, 2017.
Goldstein BG, Goldstein AO. Approach to the patient with pustular skin lesions. Revised June
29, 2016. Accessed June 7, 2017.
Question 5
Edited: Mar 3, 2017
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What is the most common cause of allergic contact dermatitis?

mercury


latex


clothing

dyes

poison

ivy

nickel

Educational Objective:
Identify common causes of allergic contact dermatitis.
Key Point:
Nickel is the most common cause of allergic contact dermatitis.
Explanation:
There are many causes of allergic contact dermatitis, but the most common cause is due to
nickel allergy. About 15% to 20% of individuals undergoing patch tests are positive for nickel
allergy. Nickel is ubiquitous: It is present in jewelry, silverware, kitchen tools, medical devices,
clothing (eg, metal fasteners), and food (eg, chocolate, nuts, oats, canned foods). Other, less
common causes include other metals (eg, mercury), fragrances, clothing dyes, lanolin,
formaldehyde, rubber, latex, topical antibiotics (bacitracin, neomycin, polymyxin), and plants
(poison ivy, poison oak, poison sumac).
Reference:
Schalock PC. Common allergens in allergic contact dermatitis. Revised December 15, 2015.
Accessed June 12, 2017.
Question 6
Edited: Mar 3, 2017
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Which of the following is true about atopic dermatitis?

This
 skin inflammation is commonly associated with low levels of immunoglobulin E (IgE).

Its
 age of onset is in the early second decade of life.

A person with this skin inflammation is likely to have a personal history and family history of asthma

A person with this skin inflammation likely has a history of inflammatory bowel disease (IBD).

Initial

treatment of this skin condition involves oral cortisone.
Educational Objective:
Identify key features of atopic dermatitis.
Key Point:
Atopic dermatitis is often associated with a personal or family history of atopy, such as eczema,
asthma, or allergic rhinitis.
Explanation:
Atopic dermatitis (eczema) can occur in children younger than 20 years of age who have
personal and family histories of allergies and asthma. Atopic dermatitis and psoriasis are both
inflammatory conditions of the skin that can be difficult to differentiate.
Atopic dermatitis commonly affects the face and flexor surfaces of the body, whereas psoriasis
commonly affects the trunk, lower back, hairline, and extensor surfaces of the body. Eczema
presents as very itchy, flaky, and dry skin, but it can also cause tiny blisters and pustules that
ooze. Psoriasis produces silver, scaly, necrotic patches of skin that continually shed. It tends to
not be moist, although there are pustular versions of psoriasis.
Initial treatment involves topical cortisone, not oral cortisone.
IBD can be but is not necessarily associated with atopic dermatitis. IgE levels tend to be
elevated in allergic disorders, and they can be a useful, although not specific, measure in
identifying causative allergens.
References:
Siegfried EC, Herbert AA. Diagnosis of atopic dermatitis: mimics, overlaps, and complications. J
Clin Med. 2015;4(5):884-917.
Stokes J, Casale T. The relationship between IgE and allergic disease. Revised May 30, 2017.
Accessed June 7, 2017.
Question 7
Edited: Mar 4, 2017
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A 32-year-old woman presents with an intensely pruritic rash on her neck, shoulders, elbows,
upper back, and knees, and she also complains of watery diarrhea. She denies myalgia, nausea,
vomiting, fever, chills, and any recent travel. She has a past medical history of type 1 diabetes
mellitus that is well controlled with insulin. She also has a long-term problem with occasional
abdominal pain that gets worse after eating.
On examination, you note a mildly erythematous papular rash in the areas mentioned above
and also tense blisters on her posterior neck (see Figure).
Figure.
There are no lesions in her mouth or on her tongue. How would you treat the rash in this
patient?

dapsone


mupirocin

cream

mycophenolate

mofetil

topical

cortisone
Educational Objective:
Describe the clinical presentation of celiac sprue and its appropriate treatment.
Key Point:
The most common dermatologic manifestation of celiac sprue is dermatitis herpetiformis. The
rash is usually self-limited if the patient strictly adheres to a gluten-free diet, but the condition
can be treated more rapidly with the antibiotic dapsone.
Explanation:
This patient’s history and presentation are most consistent with celiac sprue, a condition also
known as gluten-sensitive enteropathy, which is a chronic autoimmune disease of the digestive
tract. In celiac sprue, ingestion of gluten--commonly found in wheat, rye, and barley--causes
inflammation of the mucosa of the small intestine, and malabsorption occurs.
The most common dermatologic manifestation of celiac sprue is dermatitis herpetiformis, an
extremely pruritic rash that consists of papules and blisters. The rash is usually self-limited if the
patient strictly adheres to a gluten-free diet, but the condition can be treated more rapidly with
the antibiotic dapsone. Patients taking dapsone require monitoring for hemolytic anemia,
methemoglobinemia, agranulocytosis, and neuropathy. Dapsone does not improve
gastrointestinal mucosal pathology.
Celiac sprue is also associated with type 1 diabetes mellitus.
Topical corticosteroids can be used in conjunction with a gluten-free diet and dapsone to help
relieve pruritus, but they are not very effective on their own. Bactroban cream is not
appropriate because the patient does not appear to have a bacterial infection. Mycophenolate
mofetil is used off-label in dermatologic conditions such as psoriasis.
References:
Lexicomp website. Mycophenolate mofetil hydrochloride injection. Revised May 24, 2017.
Accessed June 7, 2017.
Paek SY, Steinberg SM, Katz SI. Remission in dermatitis herpetiformis: a cohort study. Arch
Dermatol. 2011;147(3):301-305.
Schuppan D, Dieterich W. Pathogenesis, epidemiology, and clinical manifestations of celiac
disease in adults. Revised November 8, 2016. Accessed June 7, 2017.
Question 8
Edited: Mar 3, 2017
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A 26-year-old woman presents to you complaining of recurring "red rash with a few large
bubbles" on her hands and distal arms. She tells you that the outbreaks are worse during sunny
weather, but she noticed that she did not experience them when she was on vacation. She
noticed that they tend to develop the day after working her shift as a bartender.
Which of the following is the most likely diagnosis?

impetigo


phytophotodermatitis


lupus

erythematosus

cutaneous

porphyria
Educational Objective:
Differentiate between types of photodermatitis.
Key Point:
Topical contact with citrus fruits (eg, lime) can be phototoxic after exposure to ultraviolet A
radiation. This reaction is termed phytophotodermatitis.
Explanation:
Plants containing furocoumarins, when exposed to ultraviolet A radiation, can induce
phytophotodermatitis, a photosensitivity reaction. Common plants include citrus (eg, lime),
celery, wild parsnip, and parsley. Patients typically present with erythema, edema, and bullae
24 hours after sun exposure in areas where they were in contact with the offending plant.
Cutaneous manifestations of lupus erythematosus are more likely to be scaly rather than
edematous or bullous, and they are often associated with other symptoms such as arthralgias
and oral ulcers. Cutaneous porphyria tends to be more pruritic and is not as erythematous. The
timing of the lesions and history of sun exposure are inconsistent with a bacterial infection such
as impetigo.
Reference:
Elmets CA. Photosensitivity disorders (photodermatoses): clinical manifestations, diagnosis, and
treatment. Revised December 2, 2015. Accessed June 7, 2017.
Question 9
Edited: Mar 4, 2017
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A 32-year-old man presents to you complaining of small rose-colored dots all over his chest and
back. He tells you that since this morning it seems like some of the dots are coming together to
form larger ones. The only other symptom he has is low-grade fever. You review his medical
history and note that he was presumptively treated for syphilis during his last visit 1 week ago.
What is the most likely diagnosis?

cutaneous

small-vessel vasculitis

drug-induced

exanthematous eruption

fixed

drug eruption

erythema

multiforme
Educational Objective:
Differentiate between different types of drug eruptions.
Key Point:
Drug-induced exanthematous eruptions present with a maculopapular rash in susceptible
individuals within 1 to 4 weeks of the offending agent (eg, penicillin).
Explanation:
This patient was likely treated with penicillin, which can cause all of the drug eruptions listed in
the answer choices.
Approximately 90% of drug-related rashes are drug-induced exanthematous eruptions,
characterized by diffuse erythematous macules or papules (also called morbilliform, because
they resemble the rash from viral exanthematous eruptions such as measles). In severe cases,
there may be mucosal involvement, and pustules and bullae may form. It may also be a sign of
a more severe impending reaction such as Steven-Johnson syndrome/toxic epidermal necrosis.
Causative agents include penicillins, cephalosporins, sulfonamide-containing drugs,
nonsteroidal anti-inflammatory drugs, and some anticonvulsants. Symptoms occur around 5 to
14 days of treatment, but, in patients with previous exposure, they may develop within several
days. After withdrawal of the offending drug, symptoms resolve within 5 to 14 days, although
they can still persist.
Cutaneous small-vessel vasculitis presents with palpable purpura or petechiae, often with
associated fever, urticaria, and arthralgias. Although penicillin can be an offending agent, other
drugs such as hydralazine, minocycline, and propylthiouracil are more likely. Erythema
multiforme presents with target-like lesions, often involve distal extremities, and typically occur
sooner (3-5 days) after exposure. In fixed drug eruptions, erythematous and edematous
plaques form, typically on the face, genitalia, and acral (distal limb) areas.
References:
Bircher A. Exanthematous (morbilliform) drug eruption. Revised December 4, 2015. Accessed
June 7, 2017.
Samel AD, Chu C-Y. Drug eruptions. Revised October 3, 2016. Accessed June 7, 2017.
Question 10
Edited: Mar 4, 2017
Report Question
A 42-year-old man presents to you in November with severe pruritic rash on his upper arms
(see Figure).
Figure.
He states that this is the second time he has experienced this rash. During the first time, the
rash was much milder, and it resolved soon after going on vacation in the Caribbean and using
over-the-counter topical corticosteroids. He has no other medical history, including no history
of seasonal allergies.
Which of the following is the most likely diagnosis?

atopic

dermatitis

psoriasis


allergic

contact dermatitis

nummular

dermatitis
Educational Objective:
Diagnose nummular dermatitis.
Key Point:
Nummular dermatitis is an idiopathic eczema characterized by recurrent, coin-shaped pruritic
and erythematous scaly patches. Xerosis is often an underlying factor.
Explanation:
The patient has nummular eczema or dermatitis, also known as discoid eczema. It is a chronic
relapsing disease, which often presents with very pruritic, coin-shaped erythematous lesions on
the extremities and, less commonly, on the trunk. Over time they may become more dry and
scaly with central clearing, resembling lesions of tinea corporis. Triggering factors include
xerosis, or dry skin, and environmental or contact allergens. Prevention recommendations
include using humidifiers, moisturizers, nonallergenic soaps, and laundry detergents. First-line
treatment is high-potency topical corticosteroids. For severe disease, intralesional
triamcinolone, phototherapy, and systemic therapy are potential options.
This patient has no history of exposure to suggest allergic contact dermatitis, although the
lesions can be indistinguishable. Patch testing could help exclude an allergen. Psoriatic plaques
tend to be scalier and cause less pruritus. Atopic dermatitis can present with coin-shaped
lesions; however, this is uncommon, and lesions are more likely to be located in flexor regions
of the body. In addition, the patient has no history of atopic disease to support concern for
atopic dermatitis.
Reference:
Zirwas MJ. Nummular eczema. Revised August 1, 2016. Accessed June 7, 2017.
Question 11
Edited: Mar 3, 2017
Report Question
A 63-year-old man was recently prescribed a short course of oral corticosteroids for a flare-up
of his psoriasis. Within a few days of his completing the medication, he developed diffuse
erythema and scaling involving most of his body (see Figure).
Figure.
Which of the following is true regarding this patient's condition?

He
 may have mild pruritus but likely no other symptoms or complications are present.

He
 has exfoliative dermatitis.

Rash

is most likely due to a reaction to corticosteroid use.

He
 is experiencing a worsening flare-up of his psoriasis.
Educational Objective:
Recognize the presentation of exfoliative dermatitis.
Key Point:
Exfoliative dermatitis is a potentially severe, extensive disease associated with preexisting
inflammatory dermatitis (eg, psoriasis).
Explanation:
This patient has exfoliative dermatitis, or erythroderma, where more than 90% of the skin
surface area is diffusely erythematous with scaling and then exfoliates. The most common
cause is an exacerbation of a preexisting inflammatory dermatitis (eg, psoriasis), often
occurring with treatment cessation (such as in the this case), or with immunosuppressive states
such as illness or HIV infection. It is a potentially life-threatening condition, with possible fluid
and electrolyte dysregulation and risk of infection. Patients often experience significant
pruritus, and they may complain of generalized discomfort, fatigue, and feeling cold.
Given that this patient has no history of a new exacerbating factor for his psoriasis, and that he
recently completed a course of corticosteroids, a psoriatic flare-up is very unlikely. However,
the rash could be indistinguishable from erythrodermic psoriasis, which often involves the
entire body and has similar complications to exfoliative dermatitis.
Certain medication use can cause hypersensitivity reactions and fixed drug eruptions. Although
hypersensitivity drug-induced reactions can present as exfoliative dermatitis, they are generally
not due to corticosteroids. Similarly, fixed drug eruptions are generally not caused by
corticosteroids, and they tend to produce single or few distinct, oval lesions.
References:
Davis MD. Erythroderma in adults. Revised September 21, 2016. Accessed June 7, 2017.
Feldman SR. Epidemiology, clinical manifestations, and diagnosis of psoriasis. Revised
December 9, 2015. Accessed June 7, 2017.
Shiohara T. Fixed drug eruption. Revised August 1, 2016. Accessed June 7, 2017.
Question 1
Edited: Mar 1, 2017
Report Question
A 55-year-old postmenopausal woman presents to you for evaluation after she noticed a
diffuse, pruritic rash that started without provocation 1 day earlier (see Figure).
Figure.
During today's visit, she tells you that the rash is starting to improve. She notes no lip or tongue
swelling and has no difficulty breathing or chest pain. The patient notes no new occupational,
pet, soap, or detergent exposures, and no new medications, no recent travel, and no other
environmental changes.
She does not have any known allergies, does not take any medications, and has no history of
angioedema, anaphylaxis, atopy, or prior episodes of this kind. Her vital signs are within normal
limits.
What is the most likely diagnosis?

bullous

pemphigoid

contact/atopic

dermatitis

urticaria


erythema

multiforme
Educational Objective:
Recognize the typical presentation of urticaria.
Key Point:
Urticaria is a clinical diagnosis characterized by the development of pruritic plaques, or
"wheals." In many cases, no obvious etiology can be determined.
Explanation:
The most likely diagnosis of the rash this patient is experiencing is urticaria. She presented with
a pruritic rash most consistent with urticaria, the differential diagnosis of which includes atopic
dermatitis, contact dermatitis, erythema multiforme, and bullous pemphigoid, among other
conditions.
Atopic/contact dermatitis does not usually present with pruritic plaques, or "wheals," and is
usually present in patients with a known history of atopy. The characteristic findings in contact
dermatitis include blisters, dryness, and peeling. Erythema multiforme is usually associated
with infections and medication use, with lesions located on the face and limbs that are present
for 1 week. Patients with bullous pemphigoid usually are older and have fluid-filled bullae
located on the flexor surfaces.
References:
Oakley A. The diagnosis and treatment of urticaria. Best Pract J. 2012;43:6-13. Accessed June 7,
2017.
Tran PT, et al. Allergy, hypersensitivity, angioedema, and anaphylaxis. In: Marx JA, et al. Rosen's
Emergency Medicine: Concepts and Clinical Practice. 8th ed.,2014:1543-1557.e.2.
Question 2
Edited: Mar 6, 2017
Report Question
A 31-year-old woman at 35 weeks of gestation presents to you with multiple, small pink-to-red
papules on her abdomen sparing her umbilicus. Thus far, the patient has had no complications
with her pregnancy. She notes moderate to severe pruritus on her entire abdomen that
extends to her anterior thighs.
Which of the following is the most likely cause for this patient's condition?

impetigo

herpetiformis

pruritic

folliculitis of pregnancy

pruritic

urticarial papules and plaques of pregnancy (PUPPP)

pemphigoid

gestationis

prurigo

of pregnancy
Educational Objective:
Identify benign skin lesions occurring in pregnancy that usually resolve after delivery.
Key Point:
PUPPP are benign skin lesions usually distributed in the abdomen, buttocks, and thighs. The
lesions resolve after delivery.
Explanation:
This is a classic presentation of PUPPP, which most commonly occurs in a primigravid female in
the third trimester of pregnancy. It occurs with a higher rate of prevalence in women who have
greater weight gain or multiple gestations. The most common locations of the pruritic papules
are the abdomen, buttocks, and thighs. PUPPP classically spares the umbilicus. Treatment is
symptomatic and includes emollients (moisturizers), topical steroids, or antihistamines. The
only cure for PUPPP is delivery.
Pemphigoid gestationis is an autoimmune bullous disease of pregnancy that occurs in the late
second trimester of pregnancy. It presents with red, pruritic papules around the umbilicus and
eventually spreads to other areas of the body but spares the mucous membranes. Treatment is
topical corticosteroids, oral corticosteroids, and oral antihistamines.
Impetigo herpetiformis is a form of severe pustular psoriasis that occurs on the inner thighs and
groin and can spread to the mucous membranes. Patients generally present with an elevated
sedimentation rate, leukocytosis, and hypocalcemia. The condition can be fatal without
treatment, which includes oral corticosteroids and antibiotics if secondarily infected. Calcium,
phosphate, and albumin levels must be monitored throughout the course of the disease,
because there is a higher risk of placental insufficiency and fetal death.
Pruritic folliculitis of pregnancy is rare and is characterized by pruritic, erythematous, follicular
papules that can appear any time after the first trimester of pregnancy. The abdomen and
other parts of the body are affected. Treatment is benzoyl peroxide and antihistamines.
Prurigo of pregnancy is a diagnosis of exclusion and presents with discrete, bite-like papules on
the extremities that resemble scabies. It is more common in women with an atopic history and
elevated levels of immunoglobulin E as it may be a variant of atopic dermatitis. Treatment is
with corticosteroids.
References:
Dehdashti AL, Wikas SM. Pruritic urticarial papules and plaques of pregnancy occurring
postpartum. Cutis. 2015;95(6):344-347.
Roth MM. Pregnancy dermatoses: diagnosis, management, and controversies. Am J Clin
Dermatol. 2011;12(1):25-41.
Question 3
Edited: Mar 2, 2017
Report Question
A young woman developed a pruritic eruption that rapidly moved from area to area on her skin.
This history is classic for what disease?

urticaria


allergic

contact dermatitis

dermatomyositis


erythema

nodosum

systemic

lupus erythematosus
Educational Objective:
Characterize the "migration" of pruritic papules/plaques.
Key Point:
Urticaria causes transient, pruritic papules or plaques that can appear in multiple areas of the
body and may seem to be moving from one location to another.
Explanation:
Urticaria is characterized by pruritic transient wheals, or "hives" (edematous papules or plaques
of the skin, mucous membranes, or both), that occur for 6 weeks or less. Cases lasting more
than 6 weeks are termed long-term urticaria. Acute urticaria may consist of a single attack or
several brief, recurrent attacks.
Most cases are caused by immunoglobulin–E-mediated mast-cell degranulation and histamine
release, resulting in vasodilation and fluid leakage into the dermis. The Table describes
characteristics of the lesions.
Table. Lesion Characteristics
Color:
Varies from pallid (white) to light pink to dark red
Papules, plaques, wheals
Transient wheals (nonpitting edematous papules or plaques) appear in
crops, usually sharply marginated and predominantly flat-topped
Primary Lesions
May appear oval, arcuate, or annular and as they coalesce, polycyclic, or
serpiginous
Individual lesions last < 24 hours, vary in size and shape
Location
Can involve any area of the body (eg, scalp, lips, palms, soles)
Historical Findings
Intense pruritus is a cardinal symptom
Physical Findings
(Noncutaneous)
Associated Medical
Conditions
Tests
Treatment
Common triggers:
 Foods
 Drugs
 Infections, with pruritus and hives appearing within minutes to
hours
Most common offending foods:
 Shellfish
 Strawberries
 Tomatoes
 Nuts
 Eggs
 Chocolate
 Beans
 Pork
 Yeast
 Citrus fruits
 Various seasonings
Most common drug triggers:
 Aspirin
 Certain nonsteroidal anti-inflammatory drugs
 Antibiotics (eg, penicillins, sulfonamides)
 Opiates
Physical types of urticaria due to cold, sun exposure, pressure, and
cholinergic factors
Intense pruritus suggested by scratching
Angioedema of the airway can cause respiratory distress and stridor
Acute urticaria occasionally accompanied by generalized anaphylaxis,
anaphylactic shock
Allergy (eg, food, drug)
Recent exposure to pollen, chemicals, radiocontrast dyes
Recent blood transfusion, serum, immunoglobulins
Infections observed with urticaria include:
 Gastrointestinal (with helminthic parasites)
 Hepatitis B virus
 Dermatophyte (skin)
 Yeast (vaginal)
 Urinary tract
 Sinusitis
 Dental abscesses
 Tonsillitis
Eosinophilia may be noted
Likely causes should be identified and eliminated
Antihistamines: sedating H1 blockers (eg, diphenhydramine,
hydroxyzine) may be preferable at nighttime
Nonsedating H1 blockers (eg, cetirizine) may be preferable during the
day
Avoid systemic corticosteroids, unless absolutely necessary
Erythema multiforme (target-like lesions persist > 24 hours)
Papular urticaria caused by insect bites (central punctum; not targetlike; located at sites of exposure; lesions persist > 24 hours)
Urticaria pigmentosa/mastocytosis (red-brown lesions that wheal when
scratched)
Differential Diagnosis
Early bullous pemphigoid
Dermographism (wheals follow scratching)
Urticarial vasculitis (purpuric wheals persist > 24 hours; often tender,
not pruritic; other findings of vasculitis)
Contact dermatitis (wheals progress to vesicles and dermatitis)
References:
Oakley A. The diagnosis and treatment of urticaria. Best Pract J. 2012;43:6-13. Accessed June 7,
2017.
Schaefer P. Urticaria: evaluation and treatment. Am Fam Physician. 2011;83(9):1078-1084.
Question 4
Edited: Mar 5, 2017
Report Question
A 52-year-old man with a history of hypertension and hyperlipidemia develops gout and was
treated with oral colchicine. Subsequently, he was started on oral allopurinol for correction of
his uric acid. About 2 weeks after starting allopurinol, he develops palpable purpura in both of
his lower extremities.
You order a complete blood count, which shows a normal white cell count, a hemoglobin level
of 11.0 g/dL, and a platelet count at 16,500/µL. Skin biopsy is performed. What will be the most
likely pathologic finding?

subepidermal

blister

spongiosis


non-necrotizing

perivascular infiltrate with mononuclear cells

leukocytoclastic

vasculitis
Educational Objective:
Describe the typical manifestation of leukocytoclastic vasculitis.
Key Point:
Leukocytoclastic vasculitis can be triggered by certain medication use, and it presents with
palpable purpura in the lower extremities.
Explanation:
Leukocytoclastic vasculitis is a form of small-vessel vasculitis that can be triggered by the use of
certain medications, including antibiotics (eg, penicillin, cephalosporin, sulfonamide). In
addition, phenytoin, thiazide, and allopurinol use are frequent triggers. The disease presents
with palpable purpura or petechia that are nonblanching, usually in the lower extremities. The
pathology is classic.
Non-necrotizing perivascular infiltrate with mononuclear cells is a pathologic finding of hives.
Spongiosis is associated with intercellular edema (like in eczema). A blistery disease, such as
pemphigus, can present with the pathologic finding of a subepidermal blister.
References:
Bouiller K, Audia S, Devilliers H, et al. Etiologies and prognostic factors of leukocytoclastic
vasculitis with skin involvement: a retrospective study in 112 patients. Medicine (Baltimore).
2016;95(28):e4238.
Grau RG. Drug-induced vasculitis: new insights and a changing lineup of suspects. Curr
Rheumatol Rep. 2015;17(12):71.
Micheletti RG, Werth VP. Small vessel vasculitis of the skin. Rheum Dis Clin North Am.
2015;41(1):21-32, vii.
Question 1
Edited: Aug 17, 2018
Report Question
A 50-year-old man with no significant past medical history presents to you for evaluation. For
several months he has had progressive hair loss (see Figure).
Figure.
He notes no scalp/skin rashes or nail changes. He has no constitutional symptoms. He does not
smoke cigarettes, drink alcohol, or use illicit drugs. He does not take any medications or have
any known allergies.
His vital signs are: blood pressure 130/80 mm Hg, pulse 75 beats/minute, temperature 99 °F,
respiratory rate 16 breaths/minute, and oxygen saturation 100% on room air.
What is the most likely diagnosis?

telogen

effluvium

trichotillomania


androgenic

alopecia

alopecia

areata
Educational Objective:
Characterize the signs and symptoms of androgenic alopecia.
Key Point:
Androgenic alopecia occurs over a period of years and involves the anterior, middle, temporal,
and vertex regions of the scalp.
Explanation:
The most likely diagnosis in this case is androgenic alopecia, commonly known as male-pattern
baldness, which typically occurs over a period of years and involves the anterior, mid, temporal,
and vertex regions of the scalp. The Figure shows hair loss in this distribution. The other choices
listed are not consistent with androgenic alopecia.
Alopecia areata is typically characterized by smooth, circular patches of hair loss occurring over
a period of several weeks. Patients with telogen effluvium will have a reduction in scalp hair
density, which is usually diffuse and occurs over several months. Trichotillomania is a
nonscarring type of alopecia that occurs in an irregular pattern and is classically associated with
an underlying mental health condition.
References:
Bergfeld W. Telogen effluvium. Revised June 22, 2015. Accessed June 7, 2017.
Donovan J, Goldstein B, Goldstein A. Androgenetic alopecia in men: pathogenesis, clinical
features, and diagnosis. Revised January 19, 2017. Accessed June 7, 2017.
Messenger AG. Clinical manifestations and diagnosis of alopecia areata. Revised February 8,
2017. Accessed June 7, 2017.
Shapiro J, Otberg N, Hordinksy M. Evaluation and diagnosis of hair loss. Revised May 23, 2017.
Accessed June 7, 2017.
Question 2
Edited: Aug 16, 2018
Report Question
A 40-year-old woman with no significant past medical history presents to you for evaluation of
several months of discolored nails (see Figure).
Figure.
She notes no other rashes or lesions and no pruritus, bleeding, or pain from the nails. She has
no constitutional symptoms. She does not smoke cigarettes, drink alcohol, or use illicit drugs.
She does not take any medications or have any known allergies.
Her vital signs are: blood pressure 120/80 mm Hg, pulse 70 beats/minute, temperature 99 °F,
respiratory rate 16 breaths/minute, and oxygen saturation 100% on room air.
She has not received any prior therapy for this condition.
What is the next step in the management of this condition?

Initiate

therapy with oral terbinafine.

Initiate

therapy with griseofulvin.

Initiate

therapy with fluconazole.

Initiate

therapy with oral ketoconazole.
Educational Objective:
Describe how to manage onychomycosis.
Key Point:
First-line therapy for patients with onychomycosis is oral terbinafine.
Explanation:
The most likely etiology of her discolored toenails is onychomycosis, which is characterized by a
hyperkeratotic dystrophic discolored nail. Appropriate first-line systemic therapy
for treatment of onychomycosis on multiple nails is oral terbinafine.
Clinical trials have shown that treatment with fluconazole requires a longer duration of therapy
and is not as effective as terbinafine. Griseofulvin requires a longer duration of therapy and has
a lower rate of effectiveness compared with terbinafine. Ketoconazole should not be used for
the treatment of onychomycosis because of its risks of hepatotoxicity, adrenal suppression, and
interactions with other medications. Although several other topical antifungal medications are
available, they are not as effective as systemic therapy for the treatment of onychomycosis.
References:
Ameen M, Lear JT, Madan V, Mohd Mustapa MF, Richardson M. British Association of
Dermatologists’ guidelines for the management of onychomycosis 2014. Br J
Dermatol. 2014;171(5):937-958.
References:
Scher RK. Onychomycosis: therapeutic update. J Am Acad Dermatol 1999;40(6 pt 2):S21-S26.
US Food and Drug Administration. Nizoral (ketoconazole) oral tablets: drug safety
communication - prescribing for unapproved uses including skin and nail infections continues;
linked to patient death. Published May 19, 2016. Accessed June 7, 2017.
Question 3
Edited: Aug 17, 2018
Report Question
A 50-year-old woman with no significant past medical history presents to you for evaluation of
a rash on her scalp that has been present for the past several weeks (see Figure).
Figure.
She tells you that it is intermittently itchy, but that the rash does not appear anywhere else on
her body. She has not started using any new soaps, detergents, or medications. She has had no
new exposures to chemicals or plants. She does not smoke cigarettes, drink alcohol, or use illicit
drugs. She does not take any medications.
Vital signs are: blood pressure is 110/80 mm Hg, pulse 70 beats/minute, temperature 99 °F,
respiratory rate 16 breaths/minute, and oxygen saturation 100% on room air.
What is the most likely diagnosis?

alopecia

areata

psoriasis


tinea

capitis

trichotillomania

Educational Objective:
Identify that tinea capitis is associated with alopecia.
Key Point:
Tinea capitis can be associated with alopecia.
Explanation:
This patient most likely has tinea capitis, which is characterized by scaly, pruritic patches with
alopecia and areas of alopecia with black dots. Because topical antifungals are ineffective for
this condition, treatment of tinea capitis is with oral terbinafine or griseofulvin.
Although psoriasis may be found on the scalp, it can also be found on other parts of the body
(classically, the extensor surface of knees, elbows, or sacrum). It is also associated with nail
changes. The rash from scalp psoriasis is typically an erythematous plaque with an overlying
scale that may or may not be pruritic. Alopecia areata is typically characterized by smooth,
circular patches of hair loss occurring over a period of several weeks. Trichotillomania is a
nonscarring type of alopecia that occurs in an irregular pattern and is classically associated with
an underlying mental health condition.
References:
Goldstein BG, Goldstein AO. Approach to the patient with a scalp disorder. Revised May 31,
2017. Accessed June 7, 2017.
Messenger AG. Clinical manifestations and diagnosis of alopecia areata. Revised February 8,
2017. Accessed June 7, 2017.
Shapiro J, Otberg N, Hordinksy M. Evaluation and diagnosis of hair loss. Revised May 23, 2017.
Accessed June 7, 2017.
Tey HL, Tan AS, Chan YC. Meta-analysis of randomized, controlled trials comparing griseofulvin
and terbinafine in the treatment of tinea capitis. J Am Acad Dermatol 2011;64(4):663-670.
Treat JR. Tinea capitis. Revised July 28, 2015. Accessed June 7, 2017.
Question 4
Edited: Aug 17, 2018
Report Question
A 45-year-old man with no significant past medical history presents to you for evaluation of an
itchy, red-colored rash located on his scalp that has been present for the past several weeks
(see Figure).
Figure.
Upon questioning, he tells you that he has not used any new shampoos, soaps, or medications.
He also has not worn any new hats or other headgear. He does not take any medications or
have any known allergies.
Vital signs are: blood pressure 132/80 mm Hg, pulse 75 beats/minute, respiratory rate 14
breaths/minute, oxygen saturation 99% on room air, and temperature 99 °F.
What is the most likely diagnosis?

seborrheic

dermatitis

allergic

contact dermatitis

tinea

capitis

psoriasis

Educational Objective:
Recognize the typical presentation of seborrheic dermatitis.
Key Point:
Seborrheic dermatitis is characterized by clearly defined erythematous plaques with yellow
scales and is usually found on the scalp, outer ear, face, upper trunk, and intertriginous areas.
Explanation:
This patient most likely has seborrheic dermatitis, which is typically described as erythematous
plaques with yellow scales and is commonly found on the scalp, outer ear, face, upper trunk,
and intertriginous areas. The rash shown in the Figure is consistent with this diagnosis.
Treatment is with an antifungal shampoo, such as selenium sulfide, ketoconazole, or ciclopirox.
Inflammation and itching can be treated with a high-potency steroid shampoo (eg,
fluocinolone).
Tinea capitis is characterized by scaly, pruritic patches with alopecia and areas of alopecia with
black dots. Although psoriasis may be found on the scalp, it can also be found on other parts of
the body (classically, extensor surface of knees, elbows, or sacrum). It is also associated with
nail changes. The rash from scalp psoriasis is typically an erythematous plaque with an
overlying scale that may or may not be pruritic. Allergic contact dermatitis is usually associated
with exposure to a chemical, new medication, new cream, cosmetic product, or soap/detergent
and is typically characterized by erythematous, indurated, scaly plaques with or without
vesicles.
References:
Goldstein BG, Goldstein AO. Approach to the patient with a scalp disorder. Revised May 31,
2017. Accessed June 7, 2017.
Sasseville D. Seborrheic dermatitis in adolescents and adults. Revised December 30, 2015.
Accessed June 7, 2017.
Treat JR. Tinea capitis. Revised July 28, 2015. Accessed June 7, 2017.
Yiannias J. Clinical features and diagnosis of allergic contact dermatitis. Revised July 11, 2016.
Accessed June 7, 2017.
Question 5
Edited: Aug 17, 2018
Report Question
A 47-year-old man with no significant past medical history presents to you for evaluation of
circular bald spots that have appeared on his scalp over the past several weeks (see Figure).
Figure.
His scalp does not itch, is not painful, and he has no skin rash or constitutional symptoms.
Upon questioning, he tells you that he has not used any new soaps, detergents, or shampoos.
He does not take any medications. He is not sexually active and has no prior history of sexually
transmitted infections.
Vital signs are: blood pressure is 136/80 mm Hg, pulse 72 beats/minute, respiratory rate 14
breaths/minute, oxygen saturation 99% on room air, and temperature 99 °F.
What is the most likely diagnosis?

alopecia

areata

trichotillomania


syphilis


tinea

capitis
Educational Objective:
Recognize the typical presentation of alopecia areata.
Key Point:
Alopecia areata is characterized by smooth, circular patches of hair loss occurring over a period
of several weeks.
Explanation:
This patient most likely has alopecia areata, which is typically characterized by smooth, circular
patches of hair loss that occur over a period of several weeks. The bald spot shown in the Figure
is consistent with this diagnosis. First-line therapy consists of intralesional corticosteroids.
Tinea capitis is characterized by scaly, pruritic patches with alopecia and areas of alopecia with
black dots. Secondary syphilis-related hair loss is typically diffuse and patchy. This patient’s hair
loss is focal, which is not consistent with syphilis. In addition, this patient does not have any
other symptoms of syphilis and is not sexually active, thus making this diagnosis this less likely.
Trichotillomania is a nonscarring type of alopecia that occurs in an irregular pattern and is
classically associated with an underlying mental health condition.
References:
Messenger AG. Clinical manifestations and diagnosis of alopecia areata. Revised February 8,
2017. Accessed June 7, 2017.
Messenger AG. Management of alopecia areata. Revised December 23, 2016. Accessed June 7,
2017.
Shapiro J, Otberg N, Hordinksy M. Evaluation and diagnosis of hair loss. Revised May 23, 2017.
Accessed June 7, 2017.
Treat JR. Tinea capitis. Revised July 28, 2015. Accessed June 7, 2017.
Question 6
Edited: Aug 17, 2018
Report Question
A 55-year-old woman with no significant past medical history presents to you for evaluation of
a nail lesion that has been gradually increasing in size over the past several months (see Figure).
Figure. Reproduced from Doctor V. Medical & Cosmetic Dermatology. Pyogenic granuloma.
She has no pain, pruritus, bleeding, or trauma to the area. She notes no new soaps, detergents,
shampoos, chemical exposures, or new medications. She does not take any medications, is not
sexually active, and does not have a history of intravenous drug use.
Vital signs are: blood pressure 136/80 mm Hg, pulse 72 beats/minute, respiratory rate 14
breaths/minute, oxygen saturation 99% on room air, and temperature 99 °F.
What is the most likely diagnosis?

common

wart

Kaposi

sarcoma

basal

cell carcinoma

pyogenic

granuloma
Educational Objective:
Recognize the typical presentation of pyogenic granuloma.
Key Point:
A pyogenic granulomas is a slow-growing lesion that bleeds easily and is treated by excision or
destruction by cautery or laser.
Explanation:
The most likely diagnosis in this case is pyogenic granuloma, which is best described as a small,
red papule that slowly increases in size over a period of months and bleeds easily. The Figure
shown is consistent with this diagnosis. Treatment involves surgical excision or destruction
using cautery or laser.
A common wart is typically a firm, hyperkeratotic papule. Kaposi sarcoma usually consists of
multiple, gradually enlarging violaceous papules and plaques and is associated with HIV
infection. Basal cell carcinoma is described as a gradually enlarging pearly papule.
References:
Doctor V. Medical & Cosmetic Dermatology. Pyogenic granuloma. Accessed June 7, 2017.
Goldstein BG, Goldstein AO. Overview of benign lesions of the skin. Revised March 6, 2017.
Accessed June 7, 2017.
Lawley LP. Pyogenic granuloma (lobular capillary hemangioma). Revised April 25, 2016.
Accessed June 7, 2017.
Question 1
Edited: Apr 27, 2017
Report Question
A patient presents to you with a lesion that has been present for 1 year (see Figure).
Figure.
He tells you that it has been slowly growing. He has had several previous similar lesions
removed surgically.
Which of the following is the most likely diagnosis?

sarcoidosis


pyoderma

gangrenosum

leishmaniasis


cutaneous

metastasis

basal

cell carcinoma
Educational Objective:
Describe the appearance of basal cell carcinoma.
Key Point:
Basal cell carcinoma of the skin is common and often has a pearly-pink color to translucent,
nodular appearance when exposed to sun.
Remediation:
This patient has basal cell carcinoma, the most common type of skin cancer in
immunocompetent Caucasians. Typically, the lesion presents with pearly-pink to translucent,
rolled edges with an eccentric ulceration.
Basal cell carcinoma is associated with early, intense sun exposure. Basal cell carcinoma rarely
metastasizes, and it is usually treated with surgical removal of the lesion, by excision or
curettage, or with radiotherapy. Patients with a history of basal cell carcinoma are at increased
risk for developing additional basal cell carcinomas. One-half of patients who develop basal cell
carcinoma will develop an additional basal cell carcinoma in 5 years.
Reference:
Rakel RE, Rakel D. Textbook of Family Medicine. 8th ed., 2011.
Question 2
Edited: Aug 17, 2018
Report Question
A patient presents to you for evaluation of an enlarging pigmented lesion he found on his skin
(see Figure).
Figure.
Biopsy reveals that this lesion is malignant melanoma. What characteristic is most strongly
related to the patient's prognosis?

regression


thickness

of the lesion

location

of the lesion

age
 of the patient
Educational Objective:
Discuss how the thickness of melanoma is a key predictor of its prognosis.
Key Point:
Deeper/thicker melanomas portend a poor prognosis.
Remediation:
This asymmetric, poorly circumscribed and irregularly pigmented lesion is melanoma. The
prognosis is most strongly related to the depth and thickness of the lesion, as determined on
biopsy.
Reference:
Goldman L, Schafer AI. Goldman-Cecil Medicine. 25th ed., 2015.
Question 3
Edited: Aug 17, 2018
Report Question
Which of the following is true of atypical moles (dysplastic nevi) like the one seen in this Figure?
Figure.

Patients

should be followed every 3-4 years.

Individuals

with this type of mole are at increased risk of malignant melanoma.

Every

atypical mole should be removed.

No
 specific histologic criteria exist for diagnosing these lesions.
Educational Objective:
Recognize the need for surveillance of dysplastic nevi.
Key Point:
Dysplastic nevi present a risk for evolving into melanoma and should be watched.
Remediation:
This patient has an atypical mole, also known as a dysplastic nevus. The atypical mole differs
from common acquired nevi in several respects. It is larger (≥ 8 mm), has a variegated tan,
brown, and/or pink coloration, and it has some degree of asymmetry and border irregularity.
Dysplastic nevus syndrome, characterized by numerous atypical moles and a family history of
the same, is associated with an increased risk of melanoma, not necessarily in the nevus itself.
Although patients with this syndrome are at increased risk of melanoma, it is not practical to
excise every atypical nevus. It is more practical to photograph the lesions and follow these
patients every 6 to 12 months.
Rapid change (color, size, symmetry) of a dysplastic mole usually warrants excision. Specific
histologic criteria exist regarding the diagnosis of dysplastic or atypical nevi.
References:
Naeyaert J, Brochez L. Dysplastic nevi. N Engl J Med. 2003;349:2233-2240.
Perkins A, Duffy RL. Atypical moles: diagnosis and management. Am Fam Physician.
2015;91:762-767.
Question 4
Edited: Aug 17, 2018
Report Question
A man presents to you with a history of brown spots, which he tells you he has had since birth
(see Figure).
Figure.
However, he explains that he has noticed increasing numbers of these fleshy tumors over the
past several years.
Which of the following is the most likely diagnosis?

neurofibromatosis


xeroderma

pigmentosum

Gardner

syndrome

tuberous

sclerosis

atypical

nevus syndrome
Educational Objective:
Identify the skin manifestations of neurofibromatosis.
Key Point:
The skin lesions in neurofibromatosis typically present as café au lait macules and pedunculated
soft papules.
Remediation:
This man has neurofibromatosis, which is an autosomal-dominant, inherited syndrome
characterized by multiple neurofibromas (pedunculated soft papules) and cafe au lait macules
(brown-speckled patches). Meningiomas, gliomas, and sarcomas may also occur in these
patients.
Tuberous sclerosis is characterized by hypopigmented patches (ash-leaf spot), firm papules over
the face (adenoma sebaceum), and growths around the nails (periungual fibromas).
Gardner syndrome includes multiple cysts, fibromas, and osteomas, in association with
gastrointestinal polyps with high malignant potential. Atypical nevus syndrome consists of
multiple, large-sized (≥ 8 mm), multicolored (tan to pink) nevi. Xeroderma pigmentosum has
early pigmentation but is associated with numerous types of skin cancers.
References:
Hirbe AC, Gutmann DH. Neurofibromatosis type 1: a multidisciplinary approach to care. Lancet
Neurol. 2014;13:834-843.
Williams VC, Lucas J, Babcock MA, Gutmann DH, Korf B, Maria BL. Neurofibromatosis type 1
revisited. Pediatrics. 2009;123:124-133.
Question 5
Edited: Jun 8, 2018
Report Question
A patient presents to you with a 3-week history of an 8.0-mm diameter, dark-black and brownto red-colored, slightly elevated, asymmetric lesion with an irregular border on his right arm.
The patient states that the lesion began as a small spot on his arm that just recently began
increasing in size and bleeds on occasion.
Biopsy was performed, the results of which indicated malignant melanoma with a thickness of
2.25 mm. The lesion was excised with clear margins.
Which of the following is the most significant factor associated with a poor prognosis in this
clinical scenario?

8.0-mm

diameter of the lesion

irregular

borders and asymmetric lesion

lesion

increasing in size and bleeding

lesion

thickness of 2.25 mm
Educational Objective:
Recognize lesion thickness/depth in melanoma as the primary predictor of survival and
prognosis.
Key Point:
The thickness of melanoma is inversely correlated with survival.
Explanation:
Breslow thickness is a measurement of melanoma that determines prognosis and is related to
the 5-year survival rate after surgical removal of the tumor. Previous studies have shown that a
thickness of around 0.7 to 0.8 mm represents a clinically important threshold with regards to
prognosis. When considering melanoma-specific survival, outcomes are worse for patients with
tumors with a thickness ≥0.8 mm compared with those with a thickness of <0.8 mm (hazard
ratio 1.7). Sentinel lymph node metastases are found in <5% of melanomas with a thickness of
<0.8 mm and in up to 12% of melanomas with a thickness of 0.8 mm to 1.0 mm.
The other factors listed include the ABCDE warning signs of melanoma. These include:
 Asymmetry or irregular shape
 Irregular or uneven Borders
 Color variegation containing many shades of black and brown
 Lesions > 6 mm in Diameter (size of a pencil eraser)
 Any Evolving lesion or change in size, shape, color, elevation, or bleeding, itching, or
crusting
References:
Gershenwald JE, Scolyer RA, Hess KR, et al. Melanoma of the skin. In: Amin MB, ed; American
Joint Committee on Cancer. AJCC Cancer Staging Manual. 8th ed., 2017:563.
Gershenwald JE, Scolyer RA, Hess KR, et al. Melanoma staging: Evidence-based changes in the
American Joint Committee on Cancer eighth edition cancer staging manual. CA Cancer J Clin.
2017;67(6):472-492.
Question 6
Edited: Aug 17, 2018
Report Question
What is most common type of skin cancer in the United States?

squamous

cell carcinoma

malignant

melanoma

basal

cell carcinoma

Kaposi

sarcoma

basosquamous

cell carcinoma
Educational Objective:
Describe common types of skin cancer.
Key Point:
Basal cell skin carcinoma is the most common cutaneous malignancy.
Explanation:
The most common type of skin cancer in the United States is basal cell carcinoma. In fact, more
than 90% of all skin cancers are considered to be basal cell carcinoma; it is the least serious
type of skin cancer.
Squamous cell carcinoma is more serious than basal cell carcinoma but not as serious as
malignant melanoma. Both squamous and basal cell carcinomas are considered to be non–
melanoma-type skin cancers, thus setting them apart from the more serious malignant
melanoma. In fact, malignant melanoma may spread rapidly through the lymph nodes, blood,
or internal organs and can be fatal. Basosquamous cell carcinoma is a combination of basal and
squamous cell carcinomas, as the name suggests, and is not as common as basal cell carcinoma
by itself. Kaposi sarcoma occurs in immunocompromised patients, including patients with
cancer and those with HIV/AIDS.
References:
Cancer Facts & Figures 2016 | American Cancer Society
Question 7
Edited: Aug 17, 2018
Report Question
Which of the following is correct about squamous cell carcinoma of the skin?

It metastasizes less often than basal cell carcinoma.

It is slow growing and never occurs on the mucosa.

It is described as a "rodent ulcer" with telangiectasias.

It is the most common skin cancer in the United States.

It is frequently preceded by actinic keratoses.
Educational Objective:
Examine the connection between squamous cell carcinoma and actinic keratosis.
Key Point:
Approximately 60% of cases of squamous cell carcinoma arise from actinic keratoses.
Explanation:
Squamous cell carcinomas of the skin usually appear as erythematous nodules on sun-exposed
areas, including the mucosa. These tumors are fast growing as opposed to basal cell carcinoma.
They are more aggressive and do metastasize more often than basal cell carcinoma. The
description of a "rodent ulcer" with telangiectasias is classic for basal cell carcinoma, which is
the most common skin cancer. Rough, epidermal lesions known as actinic keratoses often
precede squamous cell carcinoma.
References:
Siegel JA, Korgavkar K, Weinstock MA. Current perspective on actinic keratosis: a review. Br J
Dermatol. 2016. Epub ahead of print.
Werner RN, Sammain A, Erdmann R, Hartmann V, Stockfleth E, Nast A. The natural history of
actinic keratosis: a systematic review. Br J Dermatol. 2013;169:502-518.
Question 8
Edited: Aug 17, 2018
Report Question
A patient presents to you with a 5-year history of a slowly enlarging lesion on his scalp (see
Figure).
Figure.
It has bled several times. Which of the following is the most likely diagnosis?

wart


malignant

melanoma

basal

cell carcinoma

actinic

keratosis

squamous

cell carcinoma
Educational Objective:
Differentiate the clinical appearance and course of squamous cell skin cancer from those of
other cutaneous malignancies.
Key Point:
Unlike basal cell carcinoma or melanoma, squamous cell carcinomas often ulcerate and bleed.
Remediation:
The most likely diagnosis is squamous cell carcinoma because the lesion is large, ulcerated, and
hyperkeratotic. The patient's long history and bleeding episodes also point to this diagnosis.
Malignant melanoma is usually pigmented, except in cases of amelanotic melanoma. Basal cell
carcinoma is pink to translucent, with associated telangiectasia, often with a rolled border. It
usually lacks a hyperkeratotic scale. This would be an unusual location for a wart or callus.
Reference:
Goldman L, Schafer AI. Goldman-Cecil Medicine. 25th ed., 2015.
Question 9
Edited: Aug 17, 2018
Report Question
A patient presents to you with a lesion several centimeters in diameter that has been growing
over the last 2 years (see Figure).
Figure.
It has not improved with steroid ointments. Which of the following is the most likely diagnosis?

verrucous

carcinoma

Bowen

disease (squamous cell carcinoma in situ)

actinic

keratosis

psoriasis


nummular

eczema
Educational Objective:
Recognize Bowen disease (squamous cell carcinoma in situ).
Key Point:
Bowen disease presents with scaly and crusty erythematous plaques.
Remediation:
This is an example of Bowen disease, an intraepidermal squamous cell carcinoma. Bowen
disease may appear on any part of the body as an erythematous, slightly scaly and crusted
plaque that grows slowly and may become several centimeters in diameter, as seen in this
patient.
Nummular eczema should respond to topical steroids. Psoriasis is a well-demarcated
erythematous plaque, usually with silver scaling, and somewhat responsive to topical steroids.
Verrucous carcinoma is a type of slow-growing squamous cell carcinoma that is large,
exophytic, and hyperkeratotic. Actinic keratosis is considered a precancerous growth, occurring
on sun-exposed skin as irregular, erythematous scaly papules much smaller than those seen in
Bowen disease.
Reference:
Goldman L, Schafer AI. Goldman-Cecil Medicine. 25th ed., 2015.
Question 10
Edited: Aug 17, 2018
Report Question
A 64-year-old woman has had erythematous plaques with scaling on areas of her skin that are
not sun-exposed (see Figure).
Figure.
When she did not respond to therapies for eczema and psoriasis, biopsy was performed that
showed she had mycosis fungoides (MF).
Which of the following is the underlying disease process in MF?

T-cell

lymphoma

syphilis


psoriasis


sarcoid

Educational Objective:
Identify the appearance and cause of mycosis fungoides (MF).
Key Point:
MF, a type of cutaneous lymphoma, can present as itchy patches, tumors, and plaques that can
mimic other skin conditions.
Explanation:
MF is a cutaneous T-cell lymphoma. It can often mimic eczema or psoriasis with erythema and
scaling. It can also present as a tumor or generalized erythroderma.
Reference:
Hwang ST, Janik JE, Jaffe ES, Wilson WH. Mycosis fungoides and Sézary syndrome. Lancet.
2008;371;945-957.
Question 11
Edited: Aug 17, 2018
Report Question
A 19-year-old woman complains of a lesion on her left thumb that she tells you has been
present for approximately 2 months. She does not have any pain at the site. The lesion is 8 mm
in diameter, roughly circular and verrucous in appearance.
After trimming some superficial callous, punctate blood vessels are visible.
Which of the following is most likely correct regarding this lesion?

Biopsy

is mandatory prior to treatment to exclude malignancy.

First-line

therapy involves electrodessication and curettage.

The
 lesion is a wart, and treatment is optional because most warts will spontaneously resolve.

The
 lesions are likely caused by infection with human herpesvirus type 1.
Educational Objective:
Describe the pathogenesis and natural history of warts.
Key Point:
Cutaneus warts are caused by human papillomavirus infection and will often spontaneously
resolve. Treatment is indicated for pain, cosmesis, or because of the size of the wart.
Explanation:
Warts are caused by human papillomavirus infection. They often appear in children and
adolescents and are thought to spread by contact. Biopsy is usually not necessary due to the
typical verrucous appearance and presence of punctate blood vessels. Warts do not need to be
treated, as they often spontaneously regress. However, treatment can be offered for lesions
that are painful, unsightly, or large. Multiple therapies exist, from the simple (duct tape) to the
potentially scarring (surgery).
References:
Bacelieri R, Johnson SM. Cutaneous warts: an evidence-based approach to therapy. Am Fam
Physician. 2005;72:647-652.
Sterling JC, Gibbs S, Haque Hussain SS, Mohd Mustapa MF, Handfield-Jones SE. British
Association of Dermatologists' guidelines for the management of cutaneous warts 2014. Br J
Dermatol. 2014;171:696-712.
Question 1
Edited: Aug 17, 2018
Report Question
A patient presents to you who habitually and unconsciously rubs his elbow (see Figure).
Figure.
Which of the following is the most likely diagnosis?

psoriasis


lichen

planus

lichen

simplex chronicus

fungal

infection

lichen

amyloidosis
Educational Objective:
Recognize the manifestations of lichen simplex chronicus.
Key Point:
Lichen simplex chronicus is a variant of localized eczema and presents with a solitary, poorly
demarcated plaque with lichenification.
Explanation:
This patient has a solitary, poorly demarcated plaque with lichenification, which is characteristic
of lichen simplex chronicus, a variant of localized eczema (dermatitis). Repetitive rubbing and
scratching has caused lichenification of the skin, demonstrated by thickening of the skin and
accentuation of normal skin lines, sometimes with hyperpigmentation.
Psoriasis presents with well-demarcated scaly papules and plaques.
Fungal infections (dermatophyte) occur as well-demarcated scaly patches and plaques, often
with central clearing.
Tinea versicolor often occurs on the chest and back as hyperpigmented or hypopigmented,
slightly scaly plaques, and often coalesces into patches.
Lichen amyloidosis occurs after chronic rubbing, but it is more pebbly in its consistency and
typically occurs on the lower legs.
References:
Fazio SB, Yosipotich G. Pruritus: etiology and patient evaluation. Revised May 23, 2016.
Accessed June 13, 2017.
Fazio SB, Yosipotich G. Pruritus: overview of management. Revised May 23, 2016. Accessed
June 13, 2017.
Haber JS, Valdes-Rodriguez R, Yosipovitch G. Chronic pruritus and connective tissue disorders:
review, gaps, and future directions. Am J Clin Dermatol. 2016;17:445-449.
Yosipovitch G, Bernhard JD. Clinical practice. Chronic pruritus. N Engl J Med. 2013;368:16251634.
Question 2
Edited: Aug 17, 2018
Report Question
A woman presents to you with a 3-week history of a truncal eruption, which she tells you began
with a solitary larger plaque on the flank (see Figure).
Figure.
Which of the following is the most likely diagnosis?

psoriasis


lupus

erythematosus

lichen

planus

pityriasis

rosea

fungal

infection
Educational Objective:
Discuss how to diagnose pityriasis rosea.
Key Point:
Pityriasis rosea is a noncontagious papulosquamous rash usually confined to the trunk.
Explanation:
Pityriasis rosea is papulosquamous eruption that primarily involves the trunk. The lesions have
a characteristic "Christmas tree" configuration. The cause may be an unidentified infectious
agent or an immunologic reaction to a viral infection.
Pityriasis rosea is sometimes preceded by a viral upper respiratory infection, and a viral role in
the etiology may be suspected. The disease is not contagious, however, and has no infectious
epidemiology. It may be a postinfectious immunologic reaction.
References:
Chuh A, Zawar V, Sciallis G, Kempf W. A position statement on the management of patients
with pityriasis rosea. J Eur Acad Dermatol Venerol. 2016; 30:1670-1681.
Goldstein AO, Goldstein BG. Pityriasis rosea. Revised August 22, 2016. Accessed June 13, 2017.
Question 3
Edited: Aug 17, 2018
Report Question
A 50-year-old woman presents to you for an annual physical examination. You note the
following cutaneous finding (see Figure).
Figure. Reproduced from Braun MW. Pathology C601/C602. Published 2015.
She does not have pruritus, pain, or bleeding from the lesion.
Her vital signs are: blood pressure 122/80 mm Hg, pulse 72 beats/minute, respiratory rate 16
breaths/minute, oxygen saturation 100% on room air, and temperature 99 °F.
Which of the following medical conditions is associated with this cutaneous finding?

human

papillomavirus (HPV) infection

diabetes

mellitus

hypertension


hyperlipidemia

Educational Objective:
Examine the association between hyperlipidemia and xanthoma.
Key Point:
Xanthomas are associated with hyperlipidemia.
Explanation:
Thia patient has xanthoma, a cutaneous finding associated with hyperlipidemia. Diabetes
mellitus has been associated with acanthosis migrans. HPV infection is associated with
verruca vulgaris (cutaneous warts). Hypertension does not have any classic dermatologic
manifestations.
Xanthomas are yellowish-brown, pink, or orange lesions of the skin, subcutaneous tissue, and
tendons caused by focal infiltrates of foam cells. Foam cells are macrophages that have gorged
themselves with lipid droplets. The skin lesions may be papules, plaques, or nodules. Especially
in younger patients, xanthomas are likely to be associated with hyperlipidemia, which may be
primary or secondary.
Hyperlipidemic xanthomas occur in patients with elevated intermediate density
lipoprotein, low density lipoprotein, or very low density lipoprotein. Xanthomas occur
frequently in 4 of the 6 major groups of genetic hyperlipidemias, 2 of which are relatively
common (familial hypercholesterolemia and familial combined hyperlipidemia). Familial
hyperlipidemia should be suspected in patients with xanthomas who are younger than 40 years
or in those who have a family history of hyperlipidemia or early cardiovascular disease.
Secondary causes of hyperlipidemia to be considered in patients with xanthomas include
alcohol abuse, severe uncontrolled diabetes mellitus, dysproteinemia, severe hyperthyroidism,
hypothyroidism, biliary cirrhosis, porphyria, renal failure, systemic lupus erythematosus, and
glycogen storage diseases. Certain drug use (eg, isotretinoin, corticosteroids, estrogens) should
also be considered as a secondary cause.
Except for eyelid xanthomas in older adults, most cases of xanthoma are associated with
hyperlipidemia. However, several types of uncommon normolipidemic xanthomas are
associated with systemic disease, including multiple myeloma, other causes of
paraproteinemia, and histiocytosis.
References:
Braun MW. Pathology C601/C602. Published 2015. Accessed June 13, 2017.
Raal FJ, Santos RD. Homozygous familial hypercholesterolemia: current perspectives on
diagnosis and treatment. Atherosclerosis. 2012;223:262-268.
Wanat K, Noe MH. Cutaneous xanthomas. Revised December 8, 2015. Accessed June 13, 2017.
Question 4
Edited: Aug 17, 2018
Report Question
A 55-year-old man who does not have any prior medical history presents to you for evaluation
of a pruritic rash located on the flexor surface of his left wrist (see Figure).
Figure.
He tells you that it has been present for the past several weeks.
He notes no new soaps, detergents, chemical exposures, clothing, or plant contacts. He has not
had any recent travel or dietary changes. He is not sexually active and has no prior history of
sexually transmitted infections. He does not take any medications or have any medication
allergies.
His vital signs are: blood pressure 128/80 mm Hg, pulse 79 beats/minute, respiratory rate 14
breaths/minute, oxygen saturation 99% on room air, and temperature 98 °F.
What is the next most appropriate step in the treatment of this patient's rash?

Initiate

therapy with hyperbaric oxygen.

Initiate

treatment with a trial of topical steroids.

Initiate

phototherapy.

Initiate

treatment with methotrexate.
Educational Objective:
Identify the signs and symptoms of lichen planus and describe their management.
Key Point:
First-line therapy for lichen planus is a trial of topical steroids.
Explanation:
This patient has lichen planus, which is classically described by pruritus, purple color, polygonal,
and papules/plaques (also known as the "4 Ps"). Although hepatitis C virus has been classically
associated with lichen planus, the link remains controversial. First-line therapy for lichen planus
is a trial of topical steroids. Second-line therapies include systemic glucocorticoids,
phototherapy, and oral retinoids. Methotrexate and hyperbaric oxygen are generally not used
for treatment of this condition.
References:
Atzmony L, Reiter O, Hodak E, Gdalevich M, Mimouni D. Treatments for cutaneous lichen
planus: a systematic review and meta-analysis. Am J Clin Dermatol. 2016;17:11-22.
Ellis ME. Lichen planus. Published April 18, 2016. Accessed June 13, 2017.
Goldstein BG, Goldstein AO, Mostow E. Lichen planus. Revised January 11, 2017. Accessed June
13, 2017.
Le Cleach L, Chosidow O. Clinical practice. Lichen planus. N Engl J Med. 2012;366:723-732.
Question 5
Edited: Nov 30, 2018
Report Question
A 35-year-old man who does not have any prior medical history presents to you for evaluation
of a rash on the dorsal surface of his left upper extremity, distal to the elbow. The patient states
that the rash occasionally pruritic but is not painful. The patient says it has been present for
the past several weeks (see Figure).
He notes no new soaps, medications, detergents, chemical exposures, plant contacts, or
clothes. He does not smoke cigarettes, drink alcohol, or use illicit drugs. He is not sexually active
and has no prior history of sexually transmitted infections. He does not take any medications
and does not have any allergies.
His vital signs are: blood pressure 124/80 mm Hg, pulse 74 beats/minute, respiratory rate 14
breaths/minute, oxygen saturation 100% on room air, and temperature 99 °F.
What is the most reasonable next step in the treatment of this patient's rash?

Biopsy

the lesion.

Initiate

therapy with topical steroids.

Initiate

therapy with methotrexate.

Initiate

ultraviolet (UV) therapy.
Educational Objective:
Appreciate the signs and symptoms of psoriasis and discuss their treatment.
Key Point:
First-line treatment for localized psoriasis is topical steroids.
Explanation:
This patient likely has psoriasis, which is typically characterized by an erythematous papule or
plaque with a silver scale. Given that this patient has localized disease and has not been treated
with any other medications, the most reasonable course of action would be to initiate therapy
with topical steroids. The diagnosis of psoriasis is usually clinical.
This patient's rash is consistent with psoriasis, so biopsy is not indicated in this case. If the
etiology of the lesion was unclear, then performing a biopsy would be appropriate. Although
UV therapy and methotrexate can be used to treat psoriasis, they are typically considered
second-line therapies and would not be the next most appropriate next step in management.
References:
Feldman SR. Treatment of psoriasis. Revised May 25, 2017. Accessed June 13, 2017.
Menter A, Korman NJ, Elmets CA, et al. Guidelines of care for the management of psoriasis and
psoriatic arthritis: section 5. Guidelines of care for the treatment of psoriasis with phototherapy
and photochemotherapy. J Am Acad Dermatol. 2010;62:114-135.
Qureshi SA. What is psoriasis and how it is treated in homeopathy. Published March 17, 2015.
Accessed June 13, 2017.
Question 1
Edited: Aug 17, 2018
Report Question
A 74-year-old man with a history of diabetes mellitus and hypertension is complaining of
blistery, painful lesions on the dorsum of his hands (see Figure).
Figure. Reproduced from MDDK Online Medical Doctor. Porphyria cutanea tarda.
The lesions have been present for several months. The patient believes they are more
prominent during the warm months of the year and tend to get better during the winter when
he wears gloves. The rest of his physical examination is remarkable for an II/VI systolic murmur
in the aortic area. His laboratory results show a white blood cell count of 7.8, hemoglobin level
of 11.2, platelet count of 118, creatinine level of 0.8, aspartate transaminase level of 92, and
alanine transaminase level of 63.
The most likely cause of the patient’s lesions is which of the following?

HIV
 infection

tobacco

use

hepatitis

C virus infection

alcohol

use disorder

surreptitious

use of estrogen
Educational Objective:
Identify infection with hepatitis C virus as a cause of porphyria cutanea tarda.
Key Point:
Porphyria cutanea tarda manifests as blistering skin lesions on the dorsum of the hands and
exposed areas of the body. The most common cause of this condition is chronic hepatitis C virus
infection.
Explanation:
The patient has porphyria cutanea tarda caused by abnormal activity of enzymes in the hemebiosynthetic pathway. This condition is characterized by blistering skin lesions and scarring
predominantly on sun-exposed areas, particularly the knuckles. The lesions are usually very
pruritic and they get worse with sun exposure, although the latency between exposure and
reaction may not be immediate. Mild, nonspecific liver abnormalities could be seen in the
chemistry. The most frequent cause of porphyria cutanea tarda is hepatitis C virus infection,
and about one-half of people infected with this virus may have porphyria cutanea tarda. Other
less common conditions may also trigger porphyria cutanea tarda, including HIV infection
(usually in late stages), alcohol use disorder, tobacco use, and estrogen exposure.
References:
Garcovich S, Garcovich M, Capizzi R, Gasbarrini A, Zocco MA. Cutaneous manifestations of
hepatitis C in the era of new antiviral agents. World J Hepatol. 2015;7(27):2740-2748.
Handler NS, Handler MZ, Stephany MP, Handler GA, Schwartz RA. Porphyria cutanea tarda: an
intriguing genetic disease and marker. Int J Dermatol. 2017;56(6):e106-e117.
MDDK Online Medical Doctor. Porphyria cutanea tarda. Accessed May 18, 2017.
Question 2
Edited: Aug 16, 2018
Report Question
A 56-year-old former intravenous drug user has a positive hepatitis C antibody during
screening. Reflex polymerase chain reaction detected hepatitis C viremia. His physical
examination shows lesions suggestive of porphyria cutanea tarda (see Figure).
Figure.
What initial treatment should be offered to this patient?

hydroxychloroquine


deferoxamine


elbasvir/grazoprevir


blood

transfusion
Educational Objective:
Examine initial treatment options for porphyria cutanea tarda.
Key Point:
Porphyria cutanea tarda should be treated with hydroxychloroquine or phlebotomy. In
addition, protection from sun exposure is important. If porphyria cutanea tarda is caused by
hepatitis C, then treatment of the primary disease is indicated.
Explanation:
Porphyria cutanea tarda is a metabolic disease caused by decreased activity of uroporphobilinogen decarboxylase, an enzyme of the heme synthesis. Most cases are related due
to hepatitis C virus infection. The clinical manifestations include blistering lesions, especially on
the back of the hands and in other sun-exposed areas. This is because the lesions are
photosensitive.
Initial treatment for the lesions includes low-dose hydroxychloroquine or phlebotomy.
Chloroquine tends to be the first option for patients who may be concerned about or unwilling
to undergo phlebotomy. Phlebotomy is indicated in patients with evidence of iron overload.
Preventing exposure to sunlight is important, at least while plasma porphyrin levels are
elevated, so protective clothing, headgear (eg, hats), and adequate sunscreen should be
advised.
The primary cause of porphyria cutanea tarda should be treated. In this case, hepatitis C virus
infection should be treated with direct antiviral agents such as combination of
elbasvir/grazoprevir (after identifying the hepatitis C genotype and the extent of liver fibrosis).
However, hydroxychloroquine should be the first therapy prescribed prior to starting treatment
for hepatitis C.
No indication exists for blood transfusions in patients with porphyria cutanea tarda.
References:
Poh-Fitzpatrick MB. Porphyria cutanea tarda: treatment options revisited. Clin Gastroenterol
Hepatol. 2012;10(12):1410-1411.
Singal AK, Kormos-Hallberg C, Lee C, et al. Low-dose hydroxychloroquine is as effective as
phlebotomy in treatment of patients with porphyria cutanea tarda. Clin Gastroenterol Hepatol.
2012;10(12):1402-1409.
Question 3
Edited: Aug 17, 2018
Report Question
An otherwise healthy, 15-year-old girl presents to you because she is quite concerned about
the rash she developed on her arm (see Figure).
Figure.
She tells you that one of her relatives told her it might be a parasite beneath her skin. The
affected area is not raised, painful, or pruritic. She tells you she first noticed the lesion 24 hours
ago, and it has not changed in size or appearance.
The patient has not traveled outside the country. She owns no pets. She has not walked
barefoot on the beach. Three days ago she celebrated her birthday and wore perfume that her
aunt brought her back from South America. Two days ago she went to a picnic. She is currently
out of school and enjoying her summer vacation.
Which of the following is the most likely cause of her skin lesions?

cutaneous

larva migrans

berloque

dermatitis

contact

dermatitis

migratory

myasis
Educational Objective:
Assess berloque dermatitis as the etiology for certain skin lesions.
Key Point:
Berloque dermatitis is a hyperpigmentation caused by cosmetic products containing oil of
bergamot or other photosensitizing agents. Typically, the rash follows a streaky pattern
following the topical application of the product, and hyperpigmentation occurs after exposure
to the sun.
Explanation:
This patient has berloque dermatitis, which is a type of photodermatitis. Berloque is a term that
means trinket or charm in French. Certain plants and colognes contain furocoumarins, which
are photosensitizing agents. In this case, a perfume containing oil of bergamot was most likely
applied to the patient's moist skin shortly before she was exposed to the sun, which, in turn,
produced this unusual streaky pattern. Oil of bergamot and other psoralen-containing
fragrances have been banned from cosmetic products in the United States, but they may still be
present in products acquired abroad.
Allergic and irritant contact dermatitis are both in the differential diagnosis; however, no
specific allergen or irritant was involved in this case. In addition, contact dermatitis will not get
worse with sun exposure.
Cutaneous larva migrans causes a creeping skin eruption. This is caused by exposure to dog or
cat hookworms and frequently occurs when patients walk barefoot on sandy beaches. Although
it usually occurs abroad, cases have been reported in the southeastern part of the United
States.
Myasis or infestation by maggots usually presents as a subcutaneous nodule that causes a
sensation of irritation or crawling, and it can be seen in returning travelers or people with poor
hygiene.
References:
Gibbs NF. What is your diagnosis? Berloque dermatitis. Cutis. 2004;73(3):156, 181-182.
Wang L, Sterling B, Don P. Berloque dermatitis induced by "Florida water." Cutis. 2002;70(1):2930.
Question 4
Edited: Aug 17, 2018
Report Question
A 25-year-old woman with a history of intermittent asthma has recently returned from a
vacation trip to Cancun. During her trip, the patient developed prominent blisters on the
dorsum of her hand (see Figure).
Figure. Reproduced from Oddity Central [website].
You also note redness and swelling; the patient also tells you that she is in pain. She was
treated with wound care and, upon returning to the United States, the blisters have resolved,
but she still has denudated and macerated areas of the skin.
The patient spent time swimming in the ocean, swimming in a cenote (a natural sinkhole from
the collapse of limestone bedrock), and recalls helping a bartender squeeze limes to prepare
margaritas. The patient is concerned about a tropical dermatologic disease and is asking you for
advice.
Which of the following is the likely cause of this condition?

hookworm

infection

sea
 water

fresh

water from the cenote

lime

juice
Educational Objective:
Recognize the manifestations of phytophotodermatitis.
Key Point:
Contact with lime or other citric juices followed by exposure to the sun may cause a blistery
rash phytophotodermatitis or lime dermatitis.
Explanation:
Phytophotodermatitis is a condition characterized by the development of edema, erythema,
and blisters on sun-exposed areas after contact with vegetables (eg, cilantro, parsley) or citrus
fruits (eg, lime). The rash follows the distribution of the fluid exposure. Occasionally, the lesions
can become secondarily infected.
Contact with seawater may predispose vulnerable patients to infections with Vibrio species
or Mycobacterium marinum. Vibrio-associated cellulitis can cause blisters but is usually more
severe and seen in people with underlying liver disease.
Contact with freshwater may predispose patients to different organisms, such
as Aeromonas, that can cause necrotizing cellulitis.
Hookworms from cats and dogs may be associated with cutaneous larva migrans, a self-limited,
creeping eruption caused by the mobilization of larvae under the skin.
Treatment for phytophotodermatitis involves the use of cool compresses, emollients, topical
analgesics, or anesthetics and, occasionally, topical steroids. Patients are also advised to avoid
further sun exposure.
References:
Hankinson A, Lloyd B, Alweis R. Lime-induced phytophotodermatitis. J Community Hosp Intern
Med Perspect. 2014;4(4):25090.
Oddity Central [website]. Accessed May 18, 2017.
Raam R, DeClerck B, Jhun P, Herbert M. Phytophotodermatitis: the other "Lime" disease. Ann
Emerg Med. 2016;67(4):554-556.
Question 5
Edited: Aug 17, 2018
Report Question
A 55-year-old woman with no previous medical history presents to you after returning from a 4day trek on the Inca Trail in Peru. She has developed a prominent rash of malar distribution (see
Figure).
Figure.
The rash is raised, erythematous, and associated with a sensation of local warmth. The
nasolabial folds seem to be unaffected, and you note no pustular lesions. She is not having any
other symptoms such as joint pain, pleuritic chest pain, or pallor.
What is the most likely diagnosis?

dermatomyositis


lupus

erythematosus

rosacea


polymorphous

light eruption
Educational Objective:
Recognize the manifestations of cutaneous lupus erythematosus.
Key Point:
Cutaneous lupus erythematosus may cause a malar rash that lasts for months or years with
systemic manifestations. The clinician must be able to differentiate this condition from rosacea.
Explanation:
The patient has cutaneous lupus erythematosus, which is characterized by the presence of a
typical rash affecting the malar area. The lesions are photosensitive. The rash is erythematous
and usually consists of papules or plaques. The main differential diagnosis includes rosacea. In
typical cases of lupus, the nasal labial folds are not compromised and pustules are absent.
Cutaneous lupus may become full-blown systemic lupus erythematosus within months or years.
Treatment usually involves the use of topical steroids or hydroxychloroquine.
Dermatomyositis can cause a classic heliotrope rash on the face, characterized by violaceous
discoloration of the upper eyelids. In some cases, dermatomyositis rash may mimic the malar
erythema of lupus; however, in such instances, associated muscle weakness is generally present
as well as other skin lesions, including dyspigmentation in the neck and upper chest (shawl sign)
and papules in the knuckles (Gottron papules).
Polymorphous light eruption is also called sun allergy or sun poisoning and is characterized by
monomorphic, pruritic papules or plaques on areas exposed to the sun. Occasionally, vesicles
may develop in patients with this condition.
References:
Alniemi DT, Gutierrez A Jr, Drage LA, Wetter DA. Subacute cutaneous lupus erythematosus:
clinical characteristics, disease associations, treatments, and outcomes in a series of 90 patients
at Mayo Clinic, 1996-2011. Mayo Clin Proc. 2017;92(3):406-414.
Dessinioti C, Antoniou C. The "red face": not always rosacea. Clin Dermatol. 2017;35(2):201206.
Question 6
Edited: Aug 17, 2018
Report Question
A 37-year-old man with a history of attention deficit–hyperactivity disorder presents in the
spring with pruritic rash affecting his forearms, chest, and forehead. He believes that the
lesions 24 hours after he went to a tanning salon. The lesions are erythematous and papular
(see Figure).
Figure. Reproduced from DermQuest [website].
Some of them are confluent and look like plaques. They are pruritic. The patient mentions that
he had a similar eruption in his back almost every year when he was vacationing on the beach
as a child. However, he has not experienced these lesions for at least 5 years.
Which of the following is the most likely diagnosis?

solar

urticaria

polymorphous

light eruption

contact

dermatitis

porphyria

cutanea tarda
Educational Objective:
Recognize the manifestations of polymorphous light eruption.
Key Point:
Polymorphous light eruption is a pruritic, papular rash caused by exposure to sun or the act of
tanning. It tends to be monomorphic and have an appearance similar to prior eruptions.
Explanation:
The patient has polymorphous light eruption, a clinical condition also known as sun poisoning
or sun allergy. It is characterized by pruritic, papular rash seen on exposed areas. Sun exposure
or exposure to a tanning bed triggers the symptoms.
Typically, the lesions have a similar appearance to those of previous eruptions. Treatment
usually involves topical corticosteroids and oral antihistamines. In more severe cases, systemic
steroids may be indicated.
Solar urticaria is characterized by erythematous wheals occurring soon after exposure to the
sun, and they generally resolve within a day or so. The patient in this case does not have hives;
instead, he has papular lesions.
Porphyria cutanea tarda is a metabolic disorder frequently associated with hepatitis C virus
infection. It is characterized by blistering skin lesions and hyperpigmentation on sun-exposed
areas, particularly on the knuckles of the hands.
Contact dermatitis is a localized, inflammatory skin response to an irritant or an allergen, and it
is usually characterized by erythema and the formation of vesicles.
References:
DermQuest [website]. Accessed May 18, 2017.
Gruber-Wackernagel A, Byrne SN, Wolf P. Polymorphous light eruption: clinic aspects and
pathogenesis. Dermatol Clin. 2014;32(3):315-334, viii.
Matekovits A, Dalamaga M, Stratigos A, Katsambas A, Antoniou C. Polymorphous light eruption
under the Mediterranean sun: a clinico-epidemiological and photobiological study. Eur J
Dermatol. 2016;26(3):304-306.
Question 1
Edited: Jul 2, 2018
Report Question
A 40-year-old woman with a history of hypertension presents to you for a routine follow-up
visit. During her examination, you observe that the dorsum of her hand has well-defined, flat,
depigmented patches (see Figure).
Figure.
The patient does not have any symptoms such as pruritus, present wounds, or pain.
Which of the following conditions would this patient be most likely to have?

pernicious

anemia

irritable

bowel syndrome

type

2 diabetes mellitus

osteoarthritis

Educational Objective:
Describe the association between vitiligo and autoimmune diseases.
Key Point:
Vitiligo is frequently associated with autoimmune diseases, predominantly autoimmune thyroid
disease and pernicious anemia.
Explanation:
The diagnosis of vitiligo is relatively straightforward and is based on the clinical finding of welldemarcated, white-colored macules or patches. The disease tends to equally affect both sexes
and it frequently appears before age 30 years, although it can present at any time in life.
Vitiligo is frequently associated with autoimmune diseases, predominantly autoimmune thyroid
disease, but also pernicious anemia, type 1 diabetes mellitus, psoriasis, inflammatory bowel
disease, myasthenia gravis, systemic lupus erythematosus, and Sjögren syndrome.
Type 2 diabetes mellitus, irritable bowel syndrome, and osteoarthritis are not associated with
vitiligo.
References:
Dillon AB, Sideris A, Hadi A, Elbuluk N. Advances in vitiligo: an update on medical and surgical
treatments. J Clin Aesthet Dermatol. 2017;10(1):15-28.
Lotti T, D'Erme AM. Vitiligo as a systemic disease. Clin Dermatol. 2014;32(3):430-434.
Question 2
Edited: Aug 15, 2018
Report Question
A 55-year-old man with a history of rheumatoid arthritis presents to you because he is
concerned that he has developed a white-colored, depressed patch over his right shoulder (see
Figure).
Figure.
The patch is nonpruritic. He does not have any bleeding or pain over the affected site. Upon
questioning, he has a cousin with what he believes is a similar condition, except that his has the
white patches in larger areas of his body, including his face.
The patient does not recall any injury; however, he describes previous injections of steroids into
his shoulder joint that left the underlying skin with a "puffy" appearance.
What is the likely cause of the skin lesion?

steroid

atrophy

café

au lait macules

pityriasis

alba

vitiligo

Educational Objective:
Examine steroid injections as a cause of dermal atrophy.
Key Point:
Injections of high-dose steroids can be associated with thinning of the dermal layer and dermal
atrophy. These types of lesions must be differentiated from vitiligo.
Explanation:
This patient likely had infiltration of the skin during the injection of a high-concentration
corticosteroid into the shoulder, causing thinning of the dermal layer and producing a
hypopigmented, depressed plaque.
Vitiligo is in the differential diagnosis, but it would usually produce more extensive but flat
patches--not depressed--as in the current case. This patient has rheumatoid arthritis, which is
an autoimmune disease that is sometimes associated with vitiligo.
Café au lait macules are hyperpigmented lesions of the skin that resemble the appearance of
"coffee with milk." The lesions usually develop during childhood and may be associated with
neurofibromatosis.
Pityriasis alba is characterized by pale patches with dry and scaly skin, and it predominantly
occurs on the face of children. It is a type of dermatitis that usually responds well to steroid
creams.
References:
Khoo A, Grattan CE. Making a dent with corticosteroid injections for de Quervain's
tenosynovitis. BMJ Case Rep. 2016;2016: bcr2015214225.
Mueller SM, Tomaschett D, Vogt DR, Itin P, Cozzio A, Surber C. Topical corticosteroid concerns
from the clinicians' perspective. J Dermatolog Treat. 2016:1-5. Epub ahead of print.
Question 3
Edited: Aug 17, 2018
Report Question
A 38-year-old woman has returned from a missionary trip to Peru that lasted for 1 year. She
helped in the development of an organic farm and was outdoors most of the time. During the
last 4 months, she has developed brownish, hyperpigmented macules on the face (see Figure).
Figure.
The lesions are nonpruritic. During this visit, you order a pregnancy test, the results of which
are negative.
What would be the most appropriate initial treatment for this patient's condition?

topical

hydrocortisone

observation

only

combination

of tretinoin, hydroquinone, and fluocinolone

laser

therapy
Educational Objective:
Identify the appropriate treatment for melasma.
Key Point:
Melasma is characterized by the hyperpigmentation of sun-exposed areas of the face. It is
associated with exposure to ultraviolet light and with pregnancy. It is usually treated with a
skin-lightening therapy.
Explanation:
Melasma, also called chloasma, causes hyperpigmentation of the sun-exposed areas of the
face. It is relatively common in pregnancy and with prolonged exposure to ultraviolet radiation.
Although it is benign in nature, the disease can cause psychological distress. Several agents can
be used as skin-lightening therapy for the condition, including hydroquinone, azelaic acid, and
topical retinoids (eg, tretinoin). Usually a combination of hydroquinone, tretinoin, and a
midpotency topical corticosteroid is effective as initial therapy and has been proven effective in
a clinical trial.
Lower-potency corticosteroid creams (eg, hydrocortisone) are usually not helpful. Laser therapy
and chemical peels may be an option for patients whose condition fails to respond to first-line
agents. Make-up, especially with agents containing zinc oxide, can be helpful for protecting the
skin from ultraviolet radiation and covering up the discoloration, so it should be considered
adjuvant therapy.
References:
Rivas S, Pandya AG. Treatment of melasma with topical agents, peels and lasers: an evidencebased review. Am J Clin Dermatol. 2013;14(5):359-376.
Rodrigues M, Pandya AG. Melasma: clinical diagnosis and management options. Australas J
Dermatol. 2015;56(3):151-163.
Question 4
Edited: Aug 17, 2018
Report Question
A 16-year-old boy presents to you for a follow-up visit after a nodular lesion was removed from
his left arm. Pathology is compatible with neurofibroma. Physical examination reveals a healing
surgical wound and the presence of lesions seen in the Figure.
Figure.
What is the appropriate name for these lesions?

Becker

nevus

lentigo


café

au lait macules

von
 Recklinghausen lesions
Educational Objective:
Characterize the appearance of café au lait macules.
Key Point:
Café au lait macules are well-demarcated, evenly pigmented brown macules and patches in the
skin. They may be associated with neurofibromatosis.
Explanation:
The patient has café au lait macules or spots, which are well-demarcated, evenly pigmented,
brown-colored macules and patches resembling "coffee and milk." The presence of more than 5
of these lesions is strongly suggestive of type 1 neurofibromatosis or von Recklinghausen
disease.
Lentigo is characterized by smaller pigmented macules that usually appear in children and have
no predilection for areas exposed to the sun. They are different from freckles because they
persist. They are usually smaller in size than café au lait macules.
Becker nevus is a benign cutaneous hamartoma that presents as a brown patch usually on the
upper trunk or the shoulders in children.
Type 1 neurofibromatosis is characterized by the presence of neurofibromas and café au lait
macules.
References:
Gutmann DH, Ferner RE, Listernick RH, Korf BR, Wolters PL, Johnson KJ. Neurofibromatosis type
1. Nat Rev Dis Primers. 2017;3:17004.
St John J, Summe H, Csikesz C, Wiss K, Hay B, Belazarian L. Multiple café au lait spots in a group
of fair-skinned children without signs or symptoms of neurofibromatosis type 1. Pediatr
Dermatol. 2016;33(5):526-529.
Question 5
Edited: Aug 17, 2018
Report Question
A morbidly obese man presents to you after developing velvety, hyperpigmented lesions in the
posterior aspect of his neck (see Figure).
Figure. Reproduced from Best Online MD. Can acanthosis nigricans be prevented? Published
2015.
He has been told by his relatives that this may be associated with cancer, so he is seeking your
advice.
Which of the following conditions is the most likely cause of this skin abnormality?

obesity


squamous

cell carcinoma of the lung

use
 of metformin

sun
 exposure
Educational Objective:
Recognize that acanthosis nigricans can present as hyperpigmented lesions.
Key Point:
Acanthosis nigricans is characterized by velvety hyperpigmented lesions, predominantly in the
neck and the armpit, and frequently associated with obesity and insulin resistance.
Explanation:
The patient has acanthosis nigricans, which is a condition characterized by the development of
velvety, hyperpigmented lesions, predominantly in the neck and the armpit. This condition is
frequently associated with obesity and insulin resistance. Use of insulin and several drugs are
known to trigger this disorder, including oral contraceptives, systemic glucocorticosteroids, and
protease inhibitors. Metformin is not associated with the development of acanthosis nigricans.
Rarely, acanthosis nigricans can be associated with malignancy. In those situations, gastric
adenocarcinomas are more commonly found. The condition is treated through the
management of the underlying disorder.
References:
Best Online MD. Can acanthosis nigricans be prevented? Published 2015. Accessed June 14,
2017.
Kutlubay Z, Engin B, Bairamov O, Tüzün Y. Acanthosis nigricans: a fold intertriginous
dermatosis. Clin Dermatol. 2015;33(4):466-470.
Ng HY. Acanthosis nigricans in obese adolescents: prevalence, impact, and management
challenges. Adolesc Health Med Ther. 2016;8:1-10.
Question 6
Edited: Aug 17, 2018
Report Question
A 42-year-old woman from East Europe has been recently diagnosed with pulmonary
tuberculosis. She is receiving treatment with isoniazid, rifampin, ethambutol, and pyrazinamide,
and her sputum has become negative at 8 weeks. She is complaining of generalized fatigue,
persistent weight loss, and skin hyperpigmentation, predominantly on her face (see Figure).
Figure.
Her examination reveals a blood pressure of 90/60 mmHg. Her laboratory results show a
sodium level of 130 mEq/L.
What is the most likely diagnosis?

acanthosis

nigricans

skin
 tuberculosis

melasma

induced by antituberculosis medications

adrenal

insufficiency
Educational Objective:
Discuss how Addison disease can manifest as hyperpigmentation.
Key Point:
Adrenal insufficiency may be associated with hyperpigmentation of the face. Other symptoms
are usually present, including hypotension, weakness, weight loss, and electrolyte
abnormalities.
Explanation:
The patient has adrenal insufficiency, most likely triggered by adrenalitis caused by
disseminated tuberculosis. Adrenal insufficiency is characterized by fatigue, weight loss,
hypotension, and abnormalities in the electrolytes, including hyponatremia and hyperkalemia.
The hyperpigmentation is due to negative feedback that causes the increased production of
proopiomelanocortin, a hormone that, in turn, causes elevation of melatoninstimulating hormone. The pigmentation is usually more prominent on the face, in areas of
friction, on the palmar creases, and in areas that are normally already pigmented.
Melasma is usually localized to the face and is associated with pregnancy or sun exposure.
Certain medication use may potentially be a trigger, but the evidence for this link is sparse.
Acanthosis nigricans presents as velvety, hyperpigmented lesions, not as hypopigmented
macules.
Tuberculosis can affect any organ, but this patient's clinical presentation would be unlikely to
represent mycobacterial disease.
References:
Bornstein SR, Allolio B, Arlt W, et al. Diagnosis and treatment of primary adrenal insufficiency:
an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2016;101(2):364-389.
Nicolaides NC, Chrousos, Charmandari E. Adrenal Insufficiency. In: De Groot LJ, et al,
eds. Endotext. Revised 2013. Accessed June 14, 2017.
Question 1
Edited: Oct 11, 2018
Report Question
A 32-year-old woman with diabetes presents with a 3-day history of erythema, warmth, edema,
and pain of her right forearm. Examination shows that she is afebrile with normal vital signs and
has an edematous area of erythema with indistinct borders on her medial forearm, not
extending to the hand, with no areas of fluctuance or induration. She has full active and passive
ranges of motion, as well as normal sensation and pulses. How should her condition be
managed?

inpatient

admission, intravenous antibiotic therapy with ciprofloxacin

vancomycin

therapy

3-dimensional-view

x-ray of forearm prior to initiating antibiotics

outpatient

management with cephalexin and trimethaprim-sulfamethoxazole
Educational Objective:
Describe the appropriate treatment for nonpurulent cellulitis including risk factors that would
influence choice of antibiotics..
Key Point:
In nonpurulent cellulitis, initial coverage should be directed toward streptococci and
methicillin-sensitive Staphylococcus aureus.
Explanation:
This patient can be managed as an outpatient because of her uncomplicated cellulitis. There
are no findings suggestive of systemic infection that would require hospitalization and
parenteral antibiotics. Neither is there a risk factor for MRSA (recent hospitalizations, residence
in a long-term care facility, recent surgery, hemodialysis, HIV infection, a clinical picture of
systemic infection, prior episode of MRSA, or lack of response to earlier antibiotic treatment for
the cellulitis). Diabetes mellitus, per se, is not a risk factor except in the instance of lower
extremity cellulitis.
The most appropriate empiric choice among those listed in the answers is
trimethoprim/sulfamethoxazole and cephalexin. Recent clinical trials have raised the possibility
that the addition of trimethoprim-sulfa to cephalexin improves outcomes in patients with
MSSA. (see the 2nd reference) This combination is thus appropriate for either MSSA or MRSA.
Resistance of staphylococcal and streptococcal entities to beta-lactams is common so
clindamycin, in combination with trimethoprim/sulfamethoxazole would be a reasonable
alternative according to local experience. Close follow-up, within 24 to 48 hours, is
recommended for cellulitis, especially in the setting of diabetes, because wound healing will be
impaired and her glucose control could worsen. Osteomyelitis is unlikely with this presentation,
so radiography is unnecessary nor is hospitalization for vancomycin indicated.
References:
Stevens DL, Bisno AL, Chambers HF, et al; Infectious Diseases Society of America. Practice
guidelines for the diagnosis and management of skin and soft tissue infections: 2014
update. Clin Infect Dis. 2014;59(2):e10-e52.
Spelman D, Baddour LM, Cellulitis and skin abscess in adults: Treatment, Uptodate, last
updated July 24, 2018. Accessed Oct 10, 2018
Question 2
Edited: Sep 13, 2018
Report Question
A 25-year-old fisherman with an unknown past medical history presents to you complaining of
edema, erythema, and pain in his right lower extremity. He tells you he first noticed these
problems this morning. Since then, he has watched the erythema spread higher on his ankle
and then to his leg.
On examination, he is febrile, appears ill, and has erythema and edema to his mid shin. The foot
is violaceous on the medial aspect. No wound is found, but there are 2 large bullae that obscure
the skin of his foot. Although the foot and ankle are tense, he does have range of motion in his
toes and ankle.
Which of the following represents the best management of this patient?

Perform

punch biopsy of the skin.

Obtain

a surgical consult for urgent excision and debridement.

Insert

a needle into the dermis 1 cm from the advancing edge of cellulitis; if no pus is obtained, then

Carefully

outline the erythema and watch the advancing edge over the next 4 to 6 hours.
Educational Objective:
Discuss how to diagnose necrotizing fasciitis.
Key Point:
A suspicion of necrotizing fasciitis should prompt urgent surgical consultation.
Explanation:
Bullous cellulitis, necrotizing cellulitis, and necrotizing fasciitis cannot reliably be distinguished
on clinical examination. Examination of the fascia to determine the depth of the infection is the
only way to definitively diagnose necrotizing fasciitis vs cellulitis. The role of imaging in
diagnosis is evolving. Neither an aspirate (for Gram stain and culture for cellulitis) nor skin
biopsy will show fascial involvement. Watching the advancing edge advance quickly supports
the diagnosis of necrotizing fasciitis but is not definitive and could be dangerous over several
hours. Extensive surgical debridement and intravenous antibiotics are the appropriate next
steps.
Reference:
Andersen DK, et al, eds. Schwartz's Principles of Surgery. 10th ed., 2015.
Question 3
Edited: Aug 17, 2018
Report Question
A 54-year-old man with known systolic heart failure presents to you with a large area of
cellulitis across his upper back that has extended to his left shoulder. He states that it
developed over 1 day and has been stable for 2 days since then. On initial examination, he is
febrile with a temperature of 38.6 °C, appears fatigued, and is borderline orthostatic with mild,
resting tachycardia. No abscesses or bullae are seen on examination, and no additional areas of
cellulitis are found. How would you most likely manage his condition?

outpatient

treatment with metronidazole and follow-up in 7-10 days

inpatient

admission for broad-spectrum antibiotics while awaiting culture results

inpatient

admission for surgical debridement

outpatient

treatment with penicillin V potassium and follow-up in 3-5 days

inpatient

admission for clinical observation while awaiting culture results
Educational Objective:
Examine how to treat sepsis originating from a cutaneous infection.
Key Point:
Treat sepsis with a suspected cutaneous source with broad-spectrum antibiotics pending
culture results.
Explanation:
This patient has systemic inflammatory response syndrome (SIRS) that meets both the
temperature and tachycardia criteria. SIRS in combination with a source of infection (in this
case, significant cellulitis) is evidence of sepsis. Thus, the patient should be admitted and given
broad-spectrum antibiotics while awaiting culture results.
Metronidazole is used for anaerobes, which are uncommon for cellulitis. Penicillin-resistance
patterns make it less than a prime choice for skin infections. Due to the increasing likelihood of
methicillin-resistant Staphylococcus aureus for skin infection, vancomycin may be one of the
drugs indicated.
References:
Marx JA, et al, eds. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 8th ed., 2014.
Stevens DL, Bisno AL, Chambers HF, et al; Infectious Diseases Society of America. Practice
guidelines for the diagnosis and management of skin and soft tissue infections: 2014
update. Clin Infect Dis. 2014;59(2):e10-e52.
Question 4
Edited: Aug 17, 2018
Report Question
A 68-year-old woman with no past medical history presents to you with a cut on her finger that
she sustained while chopping vegetables 3 days ago. She says that the cut appeared clean, but
it has now become red and painful. On examination, the wound edges are edematous and
erythematous, but no pus can be expressed. Her finger and distal hand are edematous, and
there is red streaking from the wound to her proximal hand.
The infecting organism is most likely which of the following?

Escherichia

coli

group

B streptococci

Streptococcus

pneumoniae

group

A beta-hemolytic streptococci

Staphylococcus

aureus
Educational Objective:
Recognize the etiologic agents of nonpurulent cellulitis.
Key Point:
Streptococci are the most common pathogens causing nonpurulent cellulitis.
Explanation:
This woman has a wound infection with lymphangitis. In immunocompetent patients, group A
beta-hemolytic streptococci is the most common cause. S aureus and Pseudomonas species are
other less commonly encountered. S pneumoniae and E coli are uncommon causes of such
infections.
Reference:
Wolff K, et al. Fitzpatrick's Color Atlas and Synopsis of Clinical Dermatology. 7th ed., 2015.
Question 5
Edited: Aug 17, 2018
Report Question
A 72-year-old healthy man presents to you with an area of well-demarcated erythema, warmth,
and discomfort on the face. What is the most likely etiologic pathogen of this patient's
symptoms?

Staphylococcus

aureus

group

A beta-hemolytic streptococci

Klebsiella

pneumoniae

Haemophilus

influenza

Escherichia

coli
Educational Objective:
Identify the usual etiologic agent responsible for erysipelas.
Key Point:
Erysipelas is most often caused by infection with group A beta-hemolytic Streptococcus species.
Explanation:
Erysipelas is most commonly caused by infection with group A beta-hemolytic streptococci, and
it typically occurs on the face. Lower-extremity erysipelas is increasingly caused by infection
with non–group A streptococci. S aureus infections tend to cause more abscesses and
associated cellulitis than erysipelas. Infections with E coli and Klebsiella species are unlikely to
cause erysipelas. Infection with H influenzae was a common cause of cellulitis and erysipelas
prior to the advent of vaccination. Group B streptococci can cause erysipelas in the neonate.
Toxicity is common and its onset is often abrupt, particularly with facial erysipelas. Most cases
involving the face are associated with pharyngitis, and those involving the extremities usually
follow wounds.
References:
Stevens D. Infections of the skin, muscles, and soft tissues. In: Kasper D, et al, eds. Harrison’s
Principles of Internal Medicine. 19th ed., 2015.
Wolff K, et al. Fitzpatrick's Color Atlas and Synopsis of Clinical Dermatology. 7th ed., 2015.
Question 6
Edited: Aug 17, 2018
Report Question
An older man presents to you for evaluation. He tells you he was riding his motorcycle over a
bright sunny weekend, and, 2 days later, he developed discrete erosions on his lip (see Figure).
Figure.
Which of the following is the most likely diagnosis?

impetigo


polymorphous

light eruption

actinic

cheilitis

allergic

contact dermatitis

herpes

simplex virus infection
Educational Objective:
Discuss how to diagnose herpes simplex infection.
Key Point:
Recurrences of herpes simplex virus infection with groups of typical-appearing erosions can be
prompted by exposure to the sun.
Explanation:
This patient has well-demarcated, discrete erosions over his lip. The discrete, punched-out,
grouped erosions are typical of herpes simplex virus infection. Outbreaks may be prompted by
sun exposure.
Impetigo may also have similar erosions, but it usually does not present as discrete, punchedout lesions, and impetigo is often associated with a golden, yellow crust. Allergic contact
dermatitis presents with well demarcated, linear, or angular eczematous patches with vesicles,
but the location would be unusual. Polymorphous light eruption presents as a widespread
macular or papular rash in sun-exposed areas. Actinic cheilitis manifests as a hyperkeratotic
lesion on the lip that is premalignant.
Reference:
Corey L. Herpes simplex virus infections. In: Kasper D, et al, eds. Harrison’s Principles of Internal
Medicine. 19th ed., 2015:1175-1180.
Question 7
Edited: Aug 17, 2018
Report Question
A patient presents to you after acutely developing a painful vesicular eruption on one side of
his face (see Figure).
Figure.
Which of the following is the most likely diagnosis?

impetigo


herpes

zoster virus (shingles)

varicella

(chicken pox)

scabies


allergic

contact dermatitis
Educational Objective:
Discuss how to diagnose herpes zoster infection.
Key Point:
A painful, vesicular eruption in a dermatomal distribution should prompt concern for shingles,
which is caused by infection with herpes zoster virus.
Explanation:
This patient has grouped vesicles on an erythematous base that are distributed unilaterally in a
dermatomal pattern, which is typical for shingles. The condition is caused by the herpes zoster
virus.
Varicella, also known as chicken pox, has a diffuse, vesicular eruption associated with
constitutional symptoms; it is not dermatomal in distribution. Impetigo, which is a bacterial
infection caused by Staphylococcus aureusor Streptococcus species, can be vesicular but is
associated with a golden, yellow crust. Scabies can be vesicular, most often in infants, and is
associated with prominent eczematous changes. Allergic contact dermatitis is highly pruritic
and is vesicular, but it is not dermatomal and the lesions of its presentation are not grouped.
Reference:
Goldman L, Schafer AI. Goldman-Cecil Medicine. 25th ed., 2015.
Question 8
Edited: Nov 12, 2018
Report Question
A patient presents with a rash of unknown duration on her arms, trunk, and back. She
complains that the rash seems to occur every summer but disappears in the winter. Physical
examination reveals multiple, hypopigmented patches with sharp borders and fine scales.
Biopsy was performed and microscopic analysis reveals multiple, short, blunt hyphae.
What would be the initial treatment for this patient?

oral
 sulfamethoxazole/trimethoprim

mupirocin

cream

oral
 erythromycin

ketoconazole

shampoo
Educational Objective:
Recognize how to diagnose and treat patients with tinea versicolor.
Key Point:
Tinea versicolor is characterized by pigmented or hypopigmented macules and patches with
scaling, and it is treated with topical antifungals.
Explanation:
This patient has tinea versicolor, which is most commonly caused by the organism Malassezia
furfur. It commonly presents with both hyperpigmented and hypopigmented macules that
coalesce into larger patches with an adherent, fine scale. Lesions tend to be located on the
trunk and extremities, and eruptions tend to flare when the outside temperatures are high and
humid. It is diagnosed by taking a skin scraping from a scale, which would indicate the classic
"spaghetti and meatball" pattern under the microscope (the spaghetti indicates the short
hyphae, and the meatball indicates the yeast form). This organism will fluoresce yellow under a
Wood lamp. Because this organism is a type of yeast, it will not respond to antibiotic therapy.
The most common initial treatment is washing the body with antifungal shampoo, although oral
antifungals are also effective.
Reference:
Hu SW, Bigby M. Pityriasis versicolor: a systematic review of interventions. Arch Dermatol.
2010;146(10):1132-1140.
Question 9
Edited: Aug 17, 2018
Report Question
The most common site of Staphylococcus aureus colonization is which of the following?

groin


anterior

nares

oral
 mucosa

toe
 webs

axillae

Educational Objective:
Locate the most common site of Staphylococcus aureus colonization.
Key Point:
The most frequent site of S aureus colonization is the anterior nares.
Explanation:
The most common site of S aureus colonization is the anterior nares. Other moist areas like the
axillae, groin, toe webs, and oral mucosa can also be colonized.
Reference:
Lowy F. Staphylococcal infections. In: Kasper D, et al, eds. Harrison’s Principles of Internal
Medicine. 19th ed., 2015:954-963.
Question 10
Edited: Nov 12, 2018
Report Question
A 35-year-old woman who is obese presents to you with a complaint of painful growths in her
groin. She states that she has had the growths in her groin in the past on many occasions, but
they always seem to clear up on their own. The patient denies any other significant past
medical history and is not taking any medications. On examination, you note erythematous
nodular painful lesions and double comedones.
What is the most likely diagnosis?

folliculitis


hidradenitis

suppurativa

acne

vulgaris

granuloma

inguinal
Educational Objective:
Discuss how to diagnose hidradenitis suppurativa.
Key Point:
Hidradenitis suppurativa presents with multiple cutaneous abscesses, often in the skin folds,
due to the obstruction of sweat glands.
Explanation:
This patient has hidradenitis suppurativa, which is a chronic disease of the apocrine sweat
glands leading to plugging and clogging, pus formation, and possible scarring. It can occur in
anyone but it is more likely to occur in African American women who are obese. The most
common site is in the skin folds, including the axillae, groin, and under the breasts.
Like hidradenitis suppurativa, acne vulgaris demonstrates follicular hyperkeratinization leading
to comedones, inflammatory nodules, and scarring. However, acne vulgaris primarily occurs on
the face, upper, chest, and back. Folliculitis is an infection that usually presents with multiple,
superficial, inflammatory papules and pustules surrounding hair follicles. These lesions,
however, tend to be transient, unlike hidradenitis which exhibits a chronic and recurrent
course. Granuloma inguinale, arising from the sexually transmitted infection Klebsiella
granulomatis, may occur in the inguinal folds, but usually presents as red ulcers with
granulation tissue that bleeds easily.
Reference:
Hang B. Breast disorders. In: Tintinalli JE, et al, eds. Emergency Medicine: A Comprehensive
Study Guide. 8th ed., 2016:675.
Question 11
Edited: Aug 17, 2018
Report Question
A 35-year-old woman who is obese presents to you with a complaint of painful growths in her
groin. She states that she has had these growths in the past on many occasions, but they always
seem to clear up on their own. The patient denies any other significant past medical history and
is not taking any medications.
On examination, you note erythematous nodular painful lesions and double comedones. You
also note that one of the growths in her groin is large, fluctuant, and very tender.
What is the next best course of action?

surgical

excision

advise

weight loss

intralesional

triamcinolone acetonide

incision

and drainage

isotretinoin

course for 20 weeks
Educational Objective:
Identify the appropriate treatment for hidradenitis suppurativa.
Key Point:
Hidradenitis suppurativa can cause painful, acute cutaneous abscesses that can be treated with
drainage.
Explanation:
This patient has hidradenitis suppurativa, which is a chronic disease of the apocrine sweat
glands leading to plugging and clogging, pus formation, and possible scarring. It can occur in
anyone but it is more likely to occur in African American women who are obese. The most
common site is in the skin folds, including the axillae, groin, and under the breasts. The best
treatment for a fluctuant lesion is incision and drainage with a short course of antibiotics
(doxycycline, tetracycline, or minocycline) and pain medication, if necessary. Weight loss should
always be considered; however, it is not the next best course of action with a fluctuant lesion.
Surgical excision would be appropriate if the lesions had persisted for years and sinus tracts
formed. Isotretinoin should be reserved for antibiotic-resistant cases and should never be the
first choice of treatment in a patient such as the one in this case. Intralesional or injection
triamcinolone acetonide is appropriate for small cysts and should be performed by a
dermatologist.
Reference:
Hang B. Breast disorders. In: Tintinalli JE, et al, eds. Emergency Medicine: A Comprehensive
Study Guide. 8th ed., 2016:675.
Question 12
Edited: Aug 17, 2018
Report Question
A 40-year-old Mexican man presents to you with diffuse rash and large, hypopigmented
macules and plaques that are present on his thighs and face. The lesions have decreased
sensation to touch, heat, or pain. The patient also complains of muscle weakness and
numbness in his hands and feet.
What is the most likely diagnosis?

leprosy


vitiligo


pityriasis

alba

tinea

corporis

tuberculosis

Educational Objective:
Discuss how to diagnose leprosy.
Key Point:
Leprosy presents with dermatologic and peripheral nervous system manifestations.
Explanation:
This patient has leprosy, an infectious disease characterized by disfiguring skin sores, nerve
damage, and progressive debilitation. It is most common in the Hispanic population. Hallmarks
of the disease include anesthetic lesions and disfiguring nodules, especially on the face and
ears. The most effective treatment is dapsone plus rifampin.
Tinea corporis is a fungal infection, commonly known as ringworm, that consists of
erythematous scaly lesions with central clearing. Treatment is usually topical or oral antifungals
like ketoconazole cream or terbinafine. Pityriasis alba presents with small circular
hypopigmented lesions on the face and upper extremities that can be secondary to prior
infection or inflammation. Vitiligo consists of well-demarcated hypopigmented macules and
commonly occurs in young patients. It can occur in all races, but it is more apparent in darkly
pigmented patients. It is known to be autoimmune in nature, and it has been associated with
thyroid disease in 30% of patients. Tuberculosis is a pulmonary infectious disease that can have
skin manifestations, including erythematous macules or dusky-brown plaques that can occur
anywhere on the body. Biopsy is required to confirm the diagnosis.
Reference:
Gelber R. Leprosy. In: Kasper D, et al, eds. Harrison’s Principles of Internal Medicine. 19th ed.,
2015:1122-1128.
Question 13
Edited: Aug 17, 2018
Report Question
A 40-year-old Mexican man presents to you with diffuse rash and large, hypopigmented
macules and plaques that are present on his thighs and face. The lesions have decreased
sensation to touch, heat, or pain. The patient also complains of muscle weakness and
numbness in his hands and feet.
What is the best treatment for this condition?

terbinafine


dapsone

and corticosteroids

psoralen


rifampin,

pyrazinamide, isoniazid, and ethambutol

dapsone

plus rifampin
Educational Objective:
Identify the appropriate treatment for leprosy.
Key Point:
Leprosy is usually treated with a combination of dapsone and rifampin.
Explanation:
This patient has leprosy, an infectious disease characterized by disfiguring skin sores, nerve
damage, and progressive debilitation. It is most common in the Hispanic population. Hallmarks
of the disease include anesthetic lesions and disfiguring nodules, especially on the face and
ears. The most effective treatment is dapsone plus rifampin.
Tinea corporis is a fungal infection, commonly known as ringworm, that consists of
erythematous scaly lesions with central clearing. Treatment is usually topical or oral antifungals
like ketoconazole cream or terbinafine. Pityriasis alba presents with small circular
hypopigmented lesions on the face and upper extremities that can be secondary to prior
infection or inflammation. Vitiligo consists of well-demarcated hypopigmented macules and
commonly occurs in young patients. It can occur in all races, but it is more apparent in darkly
pigmented patients. It is known to be autoimmune in nature, and it has been associated with
thyroid disease in 30% of patients. Tuberculosis is a pulmonary infectious disease that can have
skin manifestations, including erythematous macules or dusky-brown plaques that can occur
anywhere on the body. Biopsy is required to confirm the diagnosis.
Reference:
Gelber R. Leprosy. In: Kasper D, et al, eds. Harrison’s Principles of Internal Medicine. 19th ed.,
2015:1122-1128.
Question 14
Edited: Aug 17, 2018
Report Question
A 25-year-old woman presents to you with a painful swollen area at the base of her nail. She
tells you that it has been present for 3 days. She recently had a manicure, which involved
applying acrylic nails. She is otherwise in good health and is only taking ethinyl
estradiol/norgestimate.
What is the most likely diagnosis?

cellulitis


paronychia


onychomycosis


onycholysis


impetigo

Educational Objective:
Discuss how to diagnose paronychia.
Key Point:
Paronychia is an infection at the base of the nail; it is sometimes fluctuant.
Explanation:
Paronychia is an infection of the skin surrounding the nail margin, although it can spread to
involve a larger area. It is commonly caused by infection with Staphylococcus
aureus or Candida species. Treatment consists of warm compresses, incision, and drainage if
the area is purulent; if the area is severe, then first-generation cephalosporins are appropriate.
Cellulitis is a localized bacterial infection that can occur anywhere and is often induced by
trauma such as an insect bite or laceration. Impetigo is a localized bacterial infection that often
presents with honey-crusted lesions caused by infection with S aureus or Streptococcus
pyogenes and is seen in children. Onychomycosis is a fungal infection of the nail with thickening
and yellow discoloration of the nail plate. Onycholysis is separation of the nail from the nail
bed.
Reference:
Rigopoulos D, Larios G, Gregoriou S, Alevizos A. Acute and chronic paronychia. Am Fam
Physician. 2008;77(3):339-346.
Question 15
Edited: Aug 17, 2018
Report Question
A 25-year-old man presents with a complaint of multiple acne breakouts around his beard. He
says it has been happening for several weeks. He states that he seems to get these breakouts
when he shaves. Currently, he is using over-the-counter benzoyl peroxide wash with some
improvement.
Examination reveals multiple papules and pustules over the beard and neck area with bilateral
mild cervical lymphadenopathy. Potassium hydroxide preparation was performed, and no
hyphae were seen. Punch biopsy was performed and the results are pending.
What is the most likely diagnosis?

folliculitis

barbae

tinea

barbae

acne

vulgaris

pustular

psoriasis

candidiasis

Educational Objective:
Discuss how to diagnose folliculitis barbae.
Key Point:
Folliculitis barbae is an infection/inflammation of the hair follicles that sometimes presents with
pustules.
Explanation:
This patient has folliculitis barbae, which defined histologically defined as the presence of
inflammatory cells within the hair follicle, creating a follicular-based pustule. Folliculitis barbae
is very common in areas covered with hair such as the back of the neck, face, and groin. Shaving
commonly aggravates the area and can lead to constant reinfection. The most common cause
of folliculitis barbae is infection with Staphylococcus aureus, but other less common causes are
infections with Pseudomonas aeruginosa ("hot tub" folliculitis), viruses, and fungi. The best
treatment for folliculitis barbae involves warm compresses to decrease the inflammation,
antibiotic ointment like mupirocin, and oral antibiotics.
Acne represents a noninfectious form of folliculitis and can be anywhere on the face, chest, or
back. Although acne is a possible diagnosis, in this instance, folliculitis barbae is the most likely
condition because it is localized on the beard area and aggravated by shaving. Tinea barbae
caused by a fungus would have positive findings on potassium hydroxide preparation.
Candidiasis represents a fungal infection and would show hyphae on potassium hydroxide
preparation. Pustular psoriasis is usually seen on the palms and soles, not in the beard area.
References:
Laureano AC, Schwartz RA, Cohen PJ. Facial bacterial infections: folliculitis. Clin
Dermatol. 2014;32(6):711-714.
Stevens DL, Bisno AL, Chambers HF, et al; Infectious Diseases Society of America. Practice
guidelines for the diagnosis and management of skin and soft tissue infections: 2014
update. Clin Infect Dis. 2014;59(2):e10-e52.
Question 16
Edited: Aug 17, 2018
Report Question
A 25-year-old man presents with a complaint of multiple acne breakouts around his beard. He
says it has been happening for several weeks. He states that he seems to get these breakouts
when he shaves. Currently, he is using over-the-counter benzoyl peroxide wash with some
improvement.
Examination reveals multiple papules and pustules over the beard and neck area with bilateral
mild cervical lymphadenopathy bilaterally. Potassium hydroxide preparation was performed,
and no hyphae were seen. Punch biopsy was performed and the results are pending.
What is the most common etiologic agent of the condition described in this patient?

Propionibacterium

acnes

Staphylococcus

aureus

Pseudomonas

aeruginosa

Tinea

mentagrophytes

Candida

albicans
Educational Objective:
Recognize the etiologic pathogens that can cause folliculitis barbae.
Key Point:
S aureus and Pseudomonas species are common bacterial pathogens in folliculitis barbae.
Explanation:
This patient has folliculitis barbae, which defined histologically defined as the presence of
inflammatory cells within the hair follicle, creating a follicular-based pustule. Folliculitis barbae
is very common in areas covered with hair such as the back of the neck, face, and groin. Shaving
commonly aggravates the area and can lead to constant reinfection.
The most common cause of folliculitis barbae is infection with S aureus, but other less common
causes are infections with P aeruginosa ("hot tub" folliculitis), viruses, and fungi. The best
treatment for folliculitis barbae involves warm compresses to decrease the inflammation,
antibiotic ointment like mupirocin, and oral antibiotics.
Acne represents a noninfectious form of folliculitis and can be anywhere on the face, chest, or
back. Although acne is a possible diagnosis, in this instance, folliculitis barbae is the most likely
condition because it is localized on the beard area and aggravated by shaving. Tinea barbae
caused by a fungus would have positive findings on potassium hydroxide preparation.
Candidiasis represents a fungal infection and would show hyphae on potassium hydroxide
preparation. Pustular psoriasis is usually seen on the palms and soles, not in the beard area.
References:
Laureano AC, Schwartz RA, Cohen PJ. Facial bacterial infections: folliculitis. Clin
Dermatol. 2014;32(6):711-714.
Stevens DL, Bisno AL, Chambers HF, et al; Infectious Diseases Society of America. Practice
guidelines for the diagnosis and management of skin and soft tissue infections: 2014
update. Clin Infect Dis. 2014;59(2):e10-e52.
Question 17
Edited: Aug 17, 2018
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A 55-year-old man who is HIV positive presents to you with rash on his chest and upper
extremities. He states that the rash has been present for 1 week and does not itch. He also
complains of high fevers (103 °F) for 3 days and nausea, vomiting, night sweats, chills, poor
appetite, and an unintentional weight loss of 5 pounds. He denies cough and chest pain, but he
does state he has generalized abdominal pain.
On examination, you note multiple red and purple papules and nodules on both his upper
extremities and thorax, but the rash does not appear on his palms or soles. When manipulated,
the lesions bleed profusely. There are no oral lesions. You also note bilateral axillary
lymphadenopathy.
Biopsy of a single lesion is performed and shows acute neutrophilic inflammation and capillary
proliferation.
What is the most likely diagnosis?

pyogenic

granuloma

bacterial

abscess

cavernous

hemangioma

bacillary

angiomatosis

Kaposi

sarcoma
Educational Objective:
Discuss how to diagnose bacillary angiomatosis.
Key Point:
In immunosuppressed patients, infection with Bartonella species can cause fever, malaise,
lymphadenopathy, and multiple skin nodules with capillary and neutrophil infiltration.
Explanation:
This patient has bacillary angiomatosis, which is a bacterial infection equally caused
by Bartonella quintana and B henselae. It is usually the result of exposure to flea-infested cats
that are also infected with B henselae(called cat-scratch disease) and the human body louse B
quintana (known as the cause of "trench fever" during World War I) in immunodeficient
individuals. Initially, it presents as numerous superficial, small red to purple papules or nodules.
If the lesions are manipulated, then they tend to bleed profusely. It is also associated with
systemic symptoms like high fever, adenopathy, nausea, vomiting, night sweats, chills, and poor
appetite. It is diagnosed with specimens obtained by biopsy and visualization of the organism
on silver stain, blood culture, and polymerase chain reaction testing. It is effectively treated
with antibiotics like erythromycin and, if treated early, has an excellent prognosis.
Pyogenic granuloma is a benign vascular lesion that often occurs secondary to trauma. It is
most common in the acral areas of the body in children. Cavernous hemangiomas are benign,
slow-growing vascular lesions that are the most common type of vascular malformation
(birthmark). These birthmarks are usually show bluish skin discoloration, local swelling, and
pain. Kaposi sarcoma is a tumor caused by human herpesvirus 8 infection that is common in
patients with immunocompromise, those with a history of organ transplant, or in those with
AIDS. It is usually located on the lower extremities and has an insidious onset and is not
associated with systemic symptoms like fever, chills, malaise, and weight loss. Bacterial abscess
is a localized collection of pus in the skin that may occur on any skin surface. Symptoms and
signs are pain and tender, firm, or fluctuant swelling. Diagnosis is usually clinical and treatment
involves incision and drainage followed by a course of antibiotics. The most common causative
organisms are Staphylococcus aureus and Streptococcus pyogenes. Recently, methicillinresistant S aureus has become a more common cause.
Reference:
Giladi M, Ephros M. Bartonella infections, including cat-scratch disease. In: Kasper D, et al,
eds. Harrison’s Principles of Internal Medicine. 19th ed., 2015:1082-1083.
Question 18
Edited: Aug 17, 2018
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A 25-year-old woman who rides horses presents to you complaining of rash on her left foot
with intense itching for 1 week. She has used over-the-counter antibiotic ointment as well as
cortisone cream with no relief. She owns several horses and dogs. Her general health is
unremarkable, and she is not taking any prescription medications. She has no known allergies.
Examination reveals a 2-inch, serpiginous erythematous lesion on the dorsal aspect of her left
foot. There are surrounding vesicles with yellow discharge on the surface.
What is the most likely diagnosis?

tinea

pedis

psoriasis


scabies


cutaneous

larva migrans

arthropod

bites
Educational Objective:
Discusshow to diagnose cutaneous larva migrans.
Key Point:
Suspect cutaneous larva migrans in patients who have a serpiginous skin eruption (caused by
burrows) and who have contact with animals, particularly in warm, humid climates.
Explanation:
This patient has cutaneous larva migrans (creeping eruption), which is the most common
tropically acquired dermatosis. The intensely pruritic, serpiginous, erythematous lesion and the
patient's exposure to horses help to guide the diagnosis.
The most common organisms that cause cutaneous larva migrans are Ancylostoma, Necator,
and Strongyloides hookworm species. Thiabendazole is considered the agent of choice in
cutaneous larva migrans. Topical application is used for early, localized lesions. Oral ivermectin
can be used as well, but topical agents should be initially attempted.
Tinea pedis is a superficial fungal infection found in the intertriginous areas such as the webs of
the toes and the soles of the feet. It is usually not serpiginous and scales are found on the
surface. Scabies is an infection caused by the mite Sarcoptes scabiei, and it is not usually limited
to a single area of the body.
Psoriasis is an inherited dermatosis that involves the flexural surfaces of the body with mild to
moderate itching. In addition, the lesions are usually well-defined, erythematous plaques with
silvery scales that bleed upon removal (Auspitz sign). Arthropod bites can occur from any type
of insect and present as individual papules, not serpiginous papules.
References:
Ma DL, Vano-Galvan S. Creeping eruption--cutaneous larva migrans. N Engl J Med.
2016;374(14):e16.
Weller P. Trichinella and other tissue nematode infections leprosy. In: Kasper D, et al,
eds. Harrison’s Principles of Internal Medicine. 19th ed., 2015:1412.
Question 19
Edited: Aug 17, 2018
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A 73-year-old woman presents to you with rash under her breast that she first noticed 3 weeks
ago. She said it started under the right breast, but then it spread rapidly to involve the area
under both breasts, and now she says it burns and itches.
Further questioning reveals recent urinary tract infection treated with
trimethoprim/sulfamethoxazole for 1 week. Examination reveals an erythematous
intertriginous eruption with satellite pustules beyond the edge of the main infection.
What is the most likely diagnosis?

psoriasis


impetigo


candidiasis


tinea

cruris

tinea

versicolor
Educational Objective:
Discuss how to diagnose cutaneous candidiasis.
Key Point:
Cutaneous candidiasis is often distinguished by the presence of "satellite" lesions beyond the
edge of main infection.
Explanation:
This patient has candidiasis, which is a superficial yeast infection commonly seen in
intertriginous areas, such as the breasts, groin, axillae, and abdominal folds. It frequently
follows an infection treated with oral antibiotics. Satellite pustules are one of the hallmarks of
this diagnosis.
Tinea cruris is seen in the groin with a sharply demarcated border and without satellite
pustules. Impetigo is a superficial bacterial infection localized to a small area of the body with
honey-crusted lesions. Tinea versicolor is a superficial fungal infection seen most often on the
trunk and upper extremities following sun exposure. It is rarely symptomatic and does not have
satellite pustules. Psoriasis is usually bilateral on the extensor surfaces of the body with silvery
scales and well-demarcated plaques. Satellite pustules are not seen.
Reference:
Lawley L, et al. Eczema, psoriasis, cutaneous infections, acne and other common skin disorders.
In: Kasper D, et al, eds. Harrison’s Principles of Internal Medicine. 19th ed., 2015:350-351.
Question 20
Edited: Aug 17, 2018
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A patient presents to you with the complaint of a whitish thick discoloring on his left great
toenail. He states that he has intense pain in his great toenail when wearing his new sneakers.
On examination, you notice a soft, dry, powdery substance that can be easily scraped away on
the left great toenail. A provisional diagnosis of onychomycosis is made based on these
findings.
What is your initial step in management of this patient's condition?

treatment

with topical antifungal creams

treatment

with oral antifungal therapy

potassium

hydroxide wet mount

culture

of nail scrapings
Educational Objective:
Discuss how to diagnose onychomycosis.
Key Point:
Potassium hydroxide wet mount of nail scrapings can be used to diagnose onychomycosis and
differentiate it from other conditions with similar manifestations.
Explanation:
A potassium hydroxide wet mount is an inexpensive and quick test to perform that will help to
differentiate whether or not a fungal infection is present. If present, then hyphae will be
present and can be viewed under the microscope. Culture of nail scrapings is a more specific
test that will help to establish the presence of dermatophytes organisms that are susceptible to
itraconazole, fluconazole, and terbinafine. Treatment should not begin until a potassium
hydroxide wet mount and culture have been performed. This is because many diseases may
mimic onychomycosis and treatment should be geared to the organism involved.
Reference:
Edwards J. Candidiasis. In: Kasper D, et al, eds. Harrison’s Principles of Internal Medicine. 19th
ed., 2015:1343.
Question 21
Edited: Aug 17, 2018
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A 58-year-old man with a history of hypertension complains of pain, swelling, and redness of his
right index finger. Examination reveals a tense, erythematous distal phalanx with an abscess
involving the lateral nail space that extends into the pulp of the fingertip.
Concerning treatment of this infection, which of the following statements is true?

Treatment

includes warm compresses, topical antibiotics, and oral analgesics.

Osteomyelitis

is present.

Treatment

requires immediate consultation with a hand surgeon.

Treatment

includes a first-generation cephalosporin, incision and drainage along the ulnar aspect of

The
 wound should be thoroughly irrigated and the skin edges approximated with nonabsorbent sutu
Educational Objective:
Describe the proper treatment of distal pulp finger infection.
Key Point:
Treatment of a distal pulp finger infection, also known as a felon, includes incision, drainage,
and antibiotics. Sometimes a hand surgeon is required.
Explanation:
A felon is an infection of the pulp of the distal finger or thumb. Traditional management of a
felon includes incision and antibiotic treatment. Incision through the fibrous septa is needed to
provide adequate drainage and will sometimes require debridement in the operating room.
Incisions should be made on the ulnar aspects of the second, third, and fourth digits, with radial
incisions of the first and fifth fingers. Closure of the skin edges is contraindicated.
Complications, although relatively uncommon, include soft tissue and bony necrosis
lymphangitis and osteomyelitis. Hand surgery consultation is an option for complex cases but
often incision and drainage will suffice.
Reference:
Rakel RE, Rakel D. Textbook of Family Medicine. 8th ed., 2011.
Question 22
Edited: Aug 17, 2018
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A 24-year-old man presents with an enlarged (3 cm), tender, posterior auricular lymph node. He
has had 2 days of fatigue and some malaise. He did not take his temperature, but thinks he was
febrile yesterday evening. He has not had any recent night sweats. He is otherwise healthy, and
he works as a retail cashier. He is monogamous with a female partner and has not had any
recent international travel.
Which of the following is the most likely cause of his lymphadenitis?

tuberculous

lymphadenitis/scrofula

lymphoma


Staphylococcus

and Streptococcus infections

rheumatoid

arthritis
Educational Objective:
List the causes of lymphadenitis.
Key Point:
The most common causes of lymphadenitis in young adults are bacterial and viral infections.
Explanation:
The most common causes of lymphadenitis in young adults are bacterial and viral infections.
While all the other options are potential etiologies of lymphadenopathy, they are much less
likely. Tuberculous lymphadenitis is the most common extrapulmonary manifestation of
tuberculosis, particularly in patients with HIV infection, but there is nothing in this patient’s
history to suggest HIV infection or tuberculosis. Lymphoma is in the differential diagnosis, but it
would typically lead to painless, persistent adenopathy. This patient does not have articular
complaints to suggest rheumatoid arthritis.
Reference:
Stringer C, Sabhaney V. Neck masses. In: Tintinalli JE, et al, eds. Emergency Medicine: A
Comprehensive Study Guide. 8th ed., 2016.
Question 23
Edited: Aug 17, 2018
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A 63-year-old woman with diabetes complicated by peripheral neuropathy has a 1.5-cm
ulceration on the plantar surface of her foot at the first metatarsal head. She has no fever, but
her white blood count is elevated at 14,000/mm3. She feels fatigued, and her blood glucose
level is elevated at 359 mg/dL. There is some cellulitis surrounding the ulcer and some
devitalized skin. Plain x-ray does not show any gas in the soft tissue and there are no clear-cut
bone erosions.
Which of the following is the most appropriate pathogen to be covered when selecting
antimicrobial therapy for this diabetic foot infection?

Clostridium

species

Bacteroides

species

Staphylococcus

and Streptococcus species

Pseudomonas

aeruginosa
Educational Objective:
Describe how to treat patients with diabetic foot ulcers.
Key Point:
Staphylococcus and Streptococcus are the most common pathogens causing diabetic foot
ulcers.
Explanation:
Species of Staphylococcus and Streptococcus are the most common pathogens that cause
diabetic foot ulcers and should be targeted with empiric antibiotic therapy. The rising
prevalence of methicillin-resistant S aureusmakes it prudent to cover that entity as well. The
other pathogens listed are potential pathogens in diabetic foot ulcers, but they are much less
common than Staphylococcus and Streptococcus species. It is generally not helpful to obtain
superficial wound cultures, because they are likely to yield many species present on the skin
surface.
Reference:
Powers A. Diabetes mellitus: complications. In: Kasper D, et al, eds. Harrison’s Principles of
Internal Medicine. 19th ed., 2015:2428-2429.
Question 24
Edited: Sep 13, 2018
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A 32-year-old man has had several days of sore throat, malaise, and a maculopapular
erythematous rash on his trunk. He takes no prescription medications on a daily basis, and his
only medical history is an inguinal hernia repair. His recent travel includes a cruise to the
Caribbean that he admits included getting drunk on several occasions and engaging in casual
sex.
You are concerned that his exanthem is viral. Which of the following tests is most likely to yield
an actionable result?

hepatitis

serologies

Coxsackie

virus serology

herpes

simplex virus serology

fourth-generation

HIV assay
Educational Objective:
Select the proper diagnostic test for HIV viral exanthem.
Key Point:
Acute HIV infection can present with an erythematous maculopapular rash and multiple,
nonspecific symptoms.
Explanation:
Acute HIV infection can present with a clinical syndrome that can include an erythematous
maculopapular rash, as well as other features such as fever, pharyngitis, lymphadenopathy,
arthralgias, headache, and malaise. A fourth-generation HIV assay includes tests for the p24
antigen and can diagnose acute infection.
Coxsackie virus can cause exanthem, but the diagnosis would not be likely with Caribbean
travel; in addition, the test result would not change management. Herpes simplex virus and
hepatitis infections do not present with this clinical picture.
Reference:
Fauci A, Lane H. Human immunodeficiency virus disease. In: Kasper D, et al, eds. Harrison’s
Principles of Internal Medicine. 19th ed., 2015:1249.
Question 25
Edited: Aug 17, 2018
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A 20-year-old college student presents with a 2 cm boil on the right side of his neck. He believes
a new shirt he was wearing for the last few days caused friction and the development of the
boil. He is concerned because his roommate was recently admitted to the hospital for a leg
abscess caused by methicillin-resistant Staphylococcus aureus (MRSA).
The patient is healthy. He has no other complaints except local pain. Vital signs are normal. He
has a 3 cm fluctuant, tender, erythematous mass in the posterior portion of the neck on the
right. You incise and debride the lesion.
You obtain 3 mL of pus and send it out for a culture.
What is the preferred antibiotic option?

doxycycline


no
 antibiotic

clindamycin


trimethoprim/sulfamethoxazole

Educational Objective:
Manage community-acquired MRSA soft tissue infections.
Key Point:
Small, community-acquired MRSA abscesses do not require an antibiotic. Incision and drainage
of the lesion is sufficient. Patients with large abscesses (e.g., greater than 5 cm) should receive
an antibiotic such as doxycycline, clindamycin, or TMP/SMX.
Explanation:
Community-acquired MRSA infections have become highly prevalent in the community. They
commonly result in soft tissue infections ranging from simple to catastrophic sepsis. Most cases
are uncomplicated infections, such as small abscesses in healthy hosts, without manifestations
of spreading or systemic compromise.
The most appropriate treatment for a simple abscess is incision and drainage with culture of
the exudate. No antibiotics are indicated in this situation. Patients with abscesses larger than 5
cm or those with systemic manifestation may receive antibiotics in addition to surgical
drainage. In such cases, antibiotic options include doxycycline, trimethoprim/sulfamethoxazole,
clindamycin, and linezolid or vancomycin.
References:
Lee MC, Rios AM, Aten MF, et al. Management and outcome of children with skin and soft
tissue abscesses caused by community-acquired methicillin-resistant Staphylococcus
aureus. Pediatr Infect Dis J. 2004;23(2):123-127.
Stevens DL, Bisno AL, et al. Practice guidelines for the diagnosis and management of skin and
soft tissue infection: 2014 update by the Infectious Diseases Society of America. Clin Infect Dis
2014; 59: 147
Question 26
Edited: Aug 17, 2018
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A 36-year-old woman with a history of poorly controlled diabetes mellitus and morbid obesity
presents to you with redness, swelling, and tenderness in her left leg following minor trauma 4
days ago. Physical examination reveals a temperature of 38.5°C, blood pressure of 122/80 mm
Hg, pulse of 96, and regular respirations of 16/minute.
You note no frank opening in the skin, but redness, warmth, and tenderness extends from the
knee to the ankle. You start her on a 24-hour course of intravenous antibiotics and she begins
to improve. Blood cultures are negative, so far. She now wishes to be discharged.
Which oral antibiotic will provide coverage for methicillin-resistant Staphylococcus
aureus infection and beta-hemolytic streptococci?

vancomycin


ciprofloxacin


clindamycin


levofloxacin

Educational Objective:
Treat a patient with cellulitis.
Key Point:
Treat cellulitis of uncertain cause with clindamycin, doxycycline, or amoxicillin plus
trimethoprim/sulfamethoxazole.
Explanation:
It may be difficult to determine the organism responsible for cellulitis. The most common
causes of cellulitis are Staphylococcus aureus or hemolytic group B streptococci. If the agent
cannot be identified, the most appropriate option is to offer treatment with a single antibiotic
or a combination of antibiotics to cover both organisms. These options include clindamycin
alone, amoxicillin, doxycycline (or minocycline), or amoxicillin plus
trimethoprim/sulfamethoxazole, or vancomycin.
References:
Liu C, Bayer A, Cosgrove SE, et al; Infectious Diseases Society of America. Clinical practice
guidelines by the Infectious Diseases Society of America for the treatment of methicillinresistant Staphylococcus aureus infections in adults and children [Erratum in Clin Infect Dis.
2011;53(3):319]. Clin Infect Dis. 2011;52(3):e18-e55.
Obaitan I, Dwyer R, et al. Failure of antibiotics in cellulitis trials: a systematic review and metaanalysis. American Journal of Emergency Medicine, 2016;34: 1645-1652
Question 1
Edited: Aug 17, 2018
Report Question
An older man presents to you with lesions on his face, which he says have been present for
several years (see Figure).
Figure.
He has similar areas of involvement in the ears and scalp. Which of the following is the most
likely diagnosis?

secondary

syphilis

traumatic

scars

lichen

planus

vitiligo


discoid

lupus erythematosus
Educational Objective:
Differentiate the manifestations of discoid lupus erythematosus from those of vitiligo.
Key Point:
Vitiligo and discoid lupus erythematosus may both be associated with pigmented, whitecolored patches; however, the latter condition is associated with scarring.
Explanation:
This patient has discoid lupus erythematosus. Although vitiligo presents with depigmented
white-colored patches, it does not result in scarring as one can appreciate on the patch on this
patient’s chin. In addition, discoid lupus will often have accentuation of hair follicles with
prominent follicular plugs.
Secondary syphilis may cause a maculopapular rash that preferentially affects the palms and
soles. Whitish discoloration would be unusual. Traumatic scars may evolve into keloids, but
white discoloration would also be unusual.
References:
Garza-Mayers AC, McClurkin M, Smith GP. Review of treatment for discoid lupus
erythematosus. Dermatol Ther. 2016;29(4):274-283.
Que SK, Weston G, Suchecki J, Ricketts J. Pigmentary disorders of the eyes and skin. Clin
Dermatol. 2015;33(2):147-158.
Question 2
Edited: Aug 17, 2018
Report Question
Which of the following is the most common precipitating event in recurrent erythema
multiforme?

connective-tissue

diseases

herpes

simplex virus infection

drugs


malignancies


diabetes

mellitus
Educational Objective:
Recognize herpes simplex virus infection as a common cause of erythema multiforme.
Key Point:
Erythema multiforme is generally associated with an infectious cause, especially herpes. In only
about 10% of cases, drug use may also trigger the syndrome.
Explanation:
Erythema multiforme can present as a variety of dermatologic reactions to multiple causes,
hence the name "multiforme." Stevens-Johnson syndrome is a severe form with mucosal
involvement, bullae, and fever. Toxic epidermal necrolysis (TEN) is a severe form, with more
than 30% of the body surface affected with extensive sloughing of the epidermis. Such severe
forms can be life threatening.
Erythema multiforme is likely an immunologic reaction to circulating immune complexes,
usually triggered by a particular drug or infection. Several studies define almost all cases of
erythema multiforme as being infectious in etiology (> 90% related to herpes simplex virus).
Other infections associated with erythema multiforme include those with Mycoplasma species.
Only about 10% of cases can be associated with drug use. Drugs associated with erythema
multiforme include penicillin, sulfonamides, phenytoin, phenylbutazone, and barbiturates.
Stevens-Johnson syndrome and TEN are almost uniformly drug-related. Erythema multiforme is
not considered a precursor of TEN. The pathology includes edema of the superficial dermis with
mononuclear and eosinophilic infiltrates and keratinocyte necrosis.
Connective-tissue disorders, diabetes mellitus, and malignancies are not associated with
erythema multiforme.
References:
Huff JC, Weston WL, Tonnesen MG. Erythema multiforme: a critical review of characteristics,
diagnostic criteria, and causes. J Am Acad Dermatol. 1983;8(6):763-775.
Sola CA, Beute TC. Erythema multiforme. J Spec Oper Med. 2014;14(3):90-92.
Question 3
Edited: Aug 17, 2018
Report Question
A patient presents to you with palmar eruption (see Figure).
Figure.
It is comprised of papules with central necrosis. It likely represents which of the following
conditions?

urticaria


secondary

syphilis

Stevens-Johnson

syndrome

dyshidrotic

eczema

erythema

multiforme
Educational Objective:
Identify the characteristics of erythema multiforme.
Key Point:
Erythema multiforme can present with a variety of skin lesions such as macules, papules,
vesicles, or bullae. Target lesions are characteristic of the condition.
Explanation:
Erythema multiforme is likely an immunologic reaction to circulating immune complexes,
usually triggered by a particular drug or infection. Several studies define almost all cases of
erythema multiforme as being infectious in etiology (> 90% related to herpes simplex virus).
Other infections associated with erythema multiforme include those with Mycoplasma species.
The term "multiforme" refers to the fact that lesions of erythema multiforme can assume a
wide variety of forms. Usually, macules initially appear and develop into papules within
approximately 2 days. Flat-topped, 1- to 2-cm distinctly marginated papules are the most
common, especially target papules (a red ring surrounds a pale ring around a red "bull's eye").
Vesicles or bullae may develop from the center of the targets. Mild cases usually have target
lesions without bullae.
Dyshidrotic eczema usually presents with pruritic vesicles on the palms. Stevens-Johnson
syndrome is a severe form of erythema multiforme associated with mucosal involvement,
bullae, and fever, which are not described in this patient. Secondary syphilis presents with
palmar and plantar rash, not generally with central necrosis. An appropriate sexual history is
usually contributory. Urticaria is manifested by hives and their distribution is usually more
disseminated.
References:
Huff JC, Weston WL, Tonnesen MG. Erythema multiforme: a critical review of characteristics,
diagnostic criteria, and causes. J Am Acad Dermatol. 1983;8(6):763-775.
Sola CA, Beute TC. Erythema multiforme. J Spec Oper Med. 2014;14(3):90-92.
Question 4
Edited: Aug 17, 2018
Report Question
A woman presents to you with an intractable urge to scratch her abdomen (see Figure).
Figure.
She states that the itchy area began as an insect bite.
Which of the following is the most likely diagnosis?

factitial

ulcer

bite
 from a brown recluse spider

allergic

contact dermatitis

necrotizing

fasciitis

pyoderma

gangrenosum
Educational Objective:
Diagnose factitial ulcers caused by intentional self-inflicted trauma.
Key Point:
Factitial ulcers, also called dermatitis artefacta, are self-inflicted lesions. They are always
located in areas accessible to self-manipulation. The condition is usually associated with
psychiatric disorders.
Explanation:
Factitial ulcers, also called dermatitis artefacta, are caused by intentional, self-inflicted trauma
and through the repetitive, mechanical trauma or application of acids, caustics, or other
ulcerative substances. These patients often have severe personality disorders or psychoses. The
condition may be induced for secondary gain or as a result of other psychologic disorders.
The differential diagnosis includes other types of ulcers (eg, stasis ulcers, vasculitic ulcers.).
Allergic contact dermatitis is incorrect because, although it may be well demarcated, angular,
and linear, it does not present as an ulcer. A bite from a brown recluse spider would cause
cellulitis with subsequent necrosis but is not recurrent.
Characteristics of factitial ulcers, their location, historical findings, associated medical
conditions and risk factors, as well as treatment options are shown in the Table below.
Color
Red
Lesion Morphology
Location and Grouping
Historical Findings and
Course
Exudates and crusts, scarring, ulcers
Lesions have an "outside job" appearance, with well-demarcated
borders and geometric, angular, stellate, linear, or other unnaturalappearing shapes
Variable, but always in an area accessible to self-manipulation
Patients may appear to overreact to questions about the origin of
such lesions, may vigorously deny any suggestion of selfmanipulation
Associated Medical
Conditions and Risk
Factors
Schizophrenia
Personality disorders (eg, borderline personality)
Treatment
Psychiatric follow-up is important, but patients often resist this form
of therapy
The usual medical treatments should be applied, but are unlikely to
be effective due to noncompliance
When "unmasked," patients are usually lost to medical follow-up for
these lesions
References:
Micheletti RG, Werth VP. Small vessel vasculitis of the skin. Rheum Dis Clin North Am.
2015;41(1):21-32.
Tammaro A, Piscopello J, Cortesi G, et al. Dermatitis artefacta: psychological and neurological
distress? Clin Ter. 2014;165(3):e223-e224.
Uçmak D, Harman M, Akkurt ZM. Dermatitis artefacta: a retrospective analysis. Cutan Ocul
Toxicol. 2014;33(1):22-27.
Question 5
Edited: Aug 17, 2018
Report Question
A 42-year-old woman with a history of diabetes mellitus who resides on a ranch in Texas
presents to you with chest pain, cough, and fever for 3 days. She thought she had the flu but
got concerned when she had a small amount of blood in her sputum.
Findings on chest x-ray show a small cavitation in the right middle lobe. In vitro assay to
diagnose latent or active Mycobacterium tuberculosis infection is negative. Her physical
examination reveals tender nodules on both shins. The patient has no history of exposure to
tuberculosis.
What would be the most likely pathology of the lesions on her lower extremities?

intense

neutrophilic infiltrate

caseating

granulomas

erythema

nodosum

spongiosis

Educational Objective:
Recognize the signs and symptoms of erythema nodosum.
Key Point:
Erythema nodosum usually manifests as tender nodules in the shins and is associated with an
infectious disease (eg, coccidioidomycosis).
Explanation:
This patient likely has coccidioidomycosis. She is an inhabitant of Texas who has developed
fever, cough, and hemoptysis, and she has a small cavitation seen on chest x-ray. Tuberculosis
could be a possibility, but she does not have epidemiologic risk factors and the findings was
negative on the in vitro assay, so she does not have latent or active M tuberculosis infection.
Coccidiomycosis is associated with erythema nodosum that manifests as painful, subcutaneous
nodules. Other infectious processes may also be associated with erythema nodosum.
Sarcoidosis and use of drugs may also cause this condition.
Caseating granulomas will be seen in tuberculosis. Intense, neutrophilic infiltrate will be seen in
an abscess or neutrophilic dermatitis. Spongiosis is a manifestation of eczema.
References:
Blake T, Manahan M, Rodins K. Erythema nodosum - a review of an uncommon
panniculitis. Dermatol Online J. 2014;20(4):22376.
Chowaniec M, Starba A, Wiland P. Erythema nodosum - review of the literature. Reumatologia.
2016;54(2):79-82.
DiCaudo DJ. Coccidioidomycosis. Semin Cutan Med Surg. 2014;33(3):140-145.
Question 6
Edited: Aug 15, 2018
Report Question
A 54-year-old man with a history of obesity, diabetes mellitus, and hypertension has an
ulceration on his right lower extremity after minor trauma (see Figure).
Figure.
He has been applying topical bacitracin ointment, but he tells you that the ulceration is still not
healing. He has some pain during dressing changes. You note a moderate amount of serous
drainage. He has no fever or chills.
What is the best management for this patient's ulceration?

cover

wound with dressing, check ankle-brachial index, and continue topical bacitracin

excisional

debridement

leave

wound open to the air, obtain culture, and start empiric antibiotics

cover

wound with dressing and compression therapy
Educational Objective:
Discuss why compression therapy is an essential treatment for venous stasis ulcers.
Key Point:
Covering the wound with dressings and applying compression therapy are keys to the
treatment of venous stasis ulcers. No antibiotics are indicated in the absence of infection.
Explanation:
The patient has developed an ulceration following minor trauma. The Figure suggests the
presence of venous insufficiency with the presence of venous stasis manifested as skin
discoloration. The ulcer is clean and does not seem to have any sloughing or infection. The
ulceration should be treated with dressing and compression therapy in the form of multilayer
compression wraps or compression stockings.
Historically, leaving the wounds open to air was recommended, but using a dressing favors the
healing by activation of the patient’s own enzymes. Obtaining a culture is not indicated because
there is no clinical evidence of infection. Continued use of topical bacitracin may predispose the
patient to contact dermatitis and is not indicated. Checking up on an ankle-brachial index is
pertinent if there is reason to be suspicious of arterial insufficiency. Excisional debridement is
recommended in the presence of sloughing or necrotic tissue.
References:
Alavi A, Sibbald RG, Phillips TJ, et al. What's new: management of venous leg ulcers: treating
venous leg ulcers. J Am Acad Dermatol. 2016;74(4):643-664.
Michael JE, Maier M. Lower extremity ulcers. Vasc Med. 2016;21(2):174-176.
Question 7
Edited: Aug 16, 2018
Report Question
A 25-year-old man with a previous medical history of recurrent nosebleeds has been admitted
to the hospital following an episode of hematemesis. He required a blood transfusion and is
now stable. Esophagogastroduodenoscopy was performed and showed evidence of
telangiectasis.
Examination of his lips is shown in the Figure.
Nosebleeds occur in his family, and he tells you that his mother died at a young age due to
hemorrhagic stroke.
Which of the following is the most likely diagnosis?

venous

insufficiency

Wilson

disease

ataxia

telangiectasia

hereditary

hemorrhagic telangiectasia
Educational Objective:
Appreciate that hereditary hemorrhagic telangiectasia manifests frequently with epistaxis and
mucocutaneous telangiectasias.
Key Point:
Hereditary hemorrhagic telangiectasia usually presents with epistaxis and mucocutaneous
telangiectasias. Gastrointestinal bleeding and a family history of bleeding issues are also
suggestive of the condition.
Explanation:
This is a young patient with a history of epistaxis who has, based on the examination of his lips,
has obvious telangiectasis. He has just been admitted to the hospital with gastrointestinal
bleeding. He also has several family members with a history of nosebleeds and a mother who
died from hemorrhagic stroke, which could have been associated with a brain arterial venous
malformation. His overall presentation seems to be compatible with hereditary hemorrhagic
telangiectasia, also known as Osler-Weber-Rendu syndrome. Of the answer choices, it is the
most likely given this patient's history and findings.
Wilson disease can be associated with liver cirrhosis and telangiectasis, but this patient does
not appear to have any symptoms that suggest hepatic disease.
Ataxia telangiectasia presents with progressive ataxia and abnormal eye movements, both of
which are not present in this patient.
Venous insufficiency may be associated with telangiectasis, but the lesions will be seen in the
patient's legs--particularly the ankles--but not in the lips.
Rosacea is also a common cause of telangiectasis.
References:
Khaitan BK, Gupta V, Rai M, Garg A. It looks familial: hereditary hemorrhagic telangiectasia. Am
J Med. 2017;130(5):537-538.
McDonald J, Pyeritz RE. Hereditary hemorrhagic telangiectasia. In: Pagon RA, et al,
eds. GeneReviews. Published June 26, 2000. Revised February 2, 2017. Accessed May 18, 2017.
Question 1
Edited: Aug 17, 2018
Report Question
A woman presents to you after developing tense blisters on her trunk and extremities (see
Figure).
Figure.
Her mouth is spared. Which of the following is the most likely diagnosis?

herpes

simplex virus (HSV) infection

arthropod

bite reactions

impetigo


pemphigus

vulgaris

bullous

pemphigoid
Educational Objective:
Recognize the manifestations of bullous pemphigoid.
Key Point:
Bullous pemphigoid is distinguished by tense bullae overlying urticarial plaques.
Explanation:
This patient has tense bullae overlying urticarial plaques, a classic presentation for bullous
pemphigoid. This is an autoimmune blistering disorder that usually occurs in older persons.
Reactions to an arthropod bite may present as vesicles or bullae, but they are usually also
associated with erythematous papules and are not so extensive and coalescing. Pemphigus is
also an autoimmune blistering disorder, but it presents as flaccid bullae and almost always
includes mucosal involvement. Impetigo is vesiculopustular and associated with golden-yellow
crusts. HSV infection presents with grouped vesicles on erythematous bases, usually on or near
a mucocutaneous surface.
Reference:
Rakel RE, Rakel D. Textbook of Family Medicine. 8th ed., 2011.
Question 2
Edited: Aug 17, 2018
Report Question
A 42-year-old woman presents to you with flaccid bullae in a generalized distribution. She
complains of sores inside her mouth that make it difficult for her to eat. She notes that her skin
sloughs off with only minor pressure. She denies weight loss, fever, and myalgias. She has no
past medical history of any skin disorder.
Findings on immunofluorescence skin biopsy show a tombstone-like fluorescent pattern.
Based on this presentation, what is the most likely diagnosis?

bullous

erythema multiforme

pemphigus

foliaceus

bullous

impetigo

pemphigus

vulgaris

bullous

pemphigoid
Educational Objective:
Discuss the clinical presentation of pemphigus vulgaris.
Key Point:
Pemphigus vulgaris is a life-threatening autoimmune skin disorder characterized by
intraepidermal blistering and sloughing of skin with minor pressure (Nikolsky sign). Mucous
membranes are often affected.
Explanation:
The patient has pemphigus vulgaris. She has flaccid bullae that exhibit a positive Nikolsky sign,
which refers to skin sloughing off with minor pressure. There is also mucosal involvement, and
findings on immunofluorescence are pathognomonic for pemphigus vulgaris.
Bullous pemphigoid occurs in the elderly, with tense blisters, and the mucous membranes are
spared. Bullous erythema multiforme typically consists of round targets with 3 different zones
and well-defined borders. It is most prominent on the extremities, and confluence of the
lesions and epidermal detachment is limited to less than 10% of body surface area. Bullous
impetigo is a toxin-mediated erythroderma that commonly affects children. It presents as
honey-crusted lesions or vesicles usually localized to a small area and is secondarily infected
with Staphylococcus aureus or Streptococcus pyogenes. Pemphigus foliaceus is an autoimmune
skin disorder characterized by loss of intercellular adhesion of keratinocytes in the upper parts
of the epidermis (acantholysis), resulting in the formation of superficial blisters. Pemphigus
foliaceus is characterized by crusty sores that often begin on the scalp that may move to the
chest, back, and face. Mouth sores do not occur. It is not as painful as pemphigus vulgaris, and
it is often misdiagnosed as dermatitis or eczema.
Reference:
Stanley JR, Amagai M. Pemphigus, bullous impetigo, and the staphylococcal scalded-skin
syndrome. N Engl J Med. 2006;355(17):1800-1810.
Question 3
Edited: Aug 17, 2018
Report Question
A 35-year-old woman presents to you with flaccid bullae in a generalized distribution. She
complains of sores inside her mouth that make it difficult for her to eat. She notes that her skin
sloughs off with only minor pressure. She denies weight loss, fever, and myalgias. She has no
past medical history of any skin disorder.
Findings on immunofluorescence skin biopsy show a tombstone-like fluorescent pattern.
What is the term used when the skin sloughs off with minor pressure?

Nikolsky

sign

Auspitz

sign

Koebner

phenomenon

Hutchinson

sign
Educational Objective:
Describe the Nikolsky sign and its significance in diagnosing pemphigus vulgaris.
Key Points:
Pemphigus vulgaris is a life-threatening autoimmune skin disorder characterized by
intraepidermal blistering and sloughing of skin with minor pressure (Nikolsky sign).
Explanation:
Nikolsky sign is the term used when the skin sloughs off with minor pressure. It occurs in
pemphigus vulgaris and pemphigus foliaceus and is positive when slight rubbing of the skin
results in exfoliation of the skin's outermost layer.
Koebner phenomenon occurs when psoriatic lesions appear at sites of cutaneous physical
trauma (scratching). Auspitz sign occurs in cases of psoriasis when removal of the overlying
scale causes pinpoint bleeding because of the thin epidermis above the dermal papillae.
Hutchinson sign is characterized by pigment on the nail folds that is common in subungual
melanoma or where a skin lesion on the tip of the nose precedes the development of
ophthalmic herpes zoster. This occurs because the nasociliary branch of the trigeminal nerve
innervates both the cornea and the tip of the nose.
Reference:
Stanley JR, Amagai M. Pemphigus, bullous impetigo, and the staphylococcal scalded-skin
syndrome. N Engl J Med. 2006;355(17):1800-1810.
Question 4
Edited: Aug 17, 2018
Report Question
A woman in her 20s was admitted to the medical intensive care unit after she acutely
developed widespread erythroderma with vesicles and bullae with resultant sheets of
epidermis sloughed off, oral erosions, and fever (see Figure).
Figure.
Which of the following is the most likely diagnosis?

staphylococcal

scalded-skin syndrome

erythema

multiforme (EM)

bullous

pemphigoid

toxic

epidermal necrolysis (TEN)

pemphigus

vulgaris
Educational Objective:
Recognize the presentation of toxic epidermal necrolysis.
Key Point:
TEN is a serious, desquamating skin condition, often caused by certain medication use, in which
the epidermis completely detaches from the dermis.
Explanation:
This patient has TEN, a hypersensitivity reaction characterized by the abrupt onset of
erythroderma followed by vesicles and bullae that completely shear away from the underlying
dermis. TEN is nearly always a medication-induced reaction, and the most common culprits are
antibiotics (sulfonamide, penicillin), anticonvulsants (phenytoin, carbamazepine,
phenobarbital), nonsteroidal anti-inflammatory drugs, and allopurinol.
TEN is a dermatologic emergency, and the most important part of therapy is cessation of the
offending medication. Therapy is otherwise supportive (intravenous fluids, blankets, local skin
care).
Pemphigus vulgaris is an autoimmune blistering disorder that may be indistinguishable from
TEN, because it also causes oral erosions and bullae. Pemphigus usually has a more indolent
course and is not associated with widespread abrupt erythroderma. Bullous pemphigoid is also
an autoimmune blistering disorder with tense blisters, often on the lower legs, but it rarely
presents with oral erosions.
Staphylococcal scalded-skin syndrome is rare in adults, usually occurs in children, and is caused
by a Staphylococcus aureus exotoxin that produces widespread erythroderma with peeling of
the skin. The split in the epidermis is superficial rather than involving the entire epidermis, as
seen in TEN.
EM is a hypersensitivity reaction that produces oral erosions and flat-topped papules and
plaques, some with a target-like morphology.
Reference:
Rosen's Emergency Medicine: Concepts and Clinical Practice. 8th ed., 2014.
Question 5
Edited: Aug 17, 2018
Report Question
Which of the following is the most common cause of toxic epidermal necrolysis (TEN)?

contact

dermatitis

drug

hypersensitivity reaction

caustic

burn to the skin

herpes

simplex virus (HSV) infection
Educational Objective
Identify common etiologies of toxic epidermal necrolysis.
Key Point
TEN is mostly caused by an adverse reaction to medication, but it can also have an infectious
etiology.
Explanation:
TEN is usually caused by an adverse reaction to certain drugs, but less commonly it is caused by
infection (eg, mycoplasma). TEN may represent a severe form of Stevens-Johnson syndrome.
Toxic shock presents with desquamating erythema due to staphylococcal infection. A similar
syndrome can result from severe streptococcal infection.
True classic erythema multiforme is considered to be mostly caused by subclinical or clinical
HSV infection. True classic erythema multiforme, while sharing many clinical and histologic
features, may no longer be considered nosologically related to TEN and Stevens-Johnson
syndrome.
Reference:
Valeyrie-Allanore L, Roujeau JC. Epidermal necrolysis (Stevens-Johnson syndrome and toxic
epidermal necrolysis). In: Goldsmith LA, et al. Fitzpatrick's Dermatology in General Medicine.
8th ed., 2012.
Question 1
Edited: Dec 20, 2018
Report Question
A child presents to you after rapidly growing the lesion seen in this Figure within the first year
of life.
Figure.
Which of the following is the treatment of choice if the lesion begins to obstruct the child's
vision?

topical

corticosteroids

intralesional

steroids

laser

therapy

oral
 propranolol
Educational Objective:
Characterize the presentation and management of infantile hemangioma.
Key Point:
Although most infantile hemangiomas will involute spontaneously after the first year of life,
large hemangiomas may require treatment and oral beta blockers are first-line therapy.
Explanation:
Capillary hemangiomas develop early in life. In general, they will grow, remain stable, and
involute spontaneously by the age of 5 years. Spontaneous involution often produces a better
cosmetic result than excision.
When hemangiomas have potential for scarring, obstructing growth, or disfigurement, they
may require treatment. Propranolol orally is the drug of choice for rapidly growing
hemangiomas that are to be treated. Use of propranolol inhibits any further growth of the
lesions and hastens involution. Propranolol is extremely effective and is now the preferred
treatment of choice. Previously, laser (pulsed dye) therapy or intralesional steroids were used.
References:
Drolet BA, Frommelt PC, Chamlin SL, et al. Initiation and use of propranolol for infantile
hemangioma: report of a consensus conference. Pediatrics. 2013;131(1):128-140.
Léauté-Labrèze C, Hoeger P, Mazereeuw-Hautier J, et al. A randomized, controlled trial of oral
propranolol in infantile hemangioma. N Engl J Med. 2015;372(8):735-746.
Martin K. Vascular disorders (chapter 650). In: Kliegman RM, et al. Nelson Textbook of
Pediatrics. 20th ed., 2016:3122-3128.
Szychta P, Stewart K, Anderson W. Treatment of infantile hemangiomas with propranolol:
clinical guidelines. Plast Reconstr Surg. 2014;133(4):852-862.
Question 2
Edited: Dec 20, 2018
Report Question
A 16-year-old girl presents to you with multiple pink, scaly skin eruptions on her upper torso
(see Figure).
Figure. Reproduced from Chuh A, Zawar V, Law M, Sciallis G3. Gianotti-Crosti syndrome,
pityriasis rosea, asymmetrical periflexural exanthem, unilateral mediothoracic exanthem,
eruptive pseudoangiomatosis, and papular-purpuric gloves and socks syndrome: a brief review
and arguments for diagnostic criteria. Infect Dis Rep. 2012;4(1):e12.
She states that she had a 2-cm eruption on her chest 1 week before. Other than the presence of
the eruptions, her only complaint is mild itching.
Which of the following statements is consistent with the diagnosis?

The
 infection is sexually transmitted and should be treated with ceftriaxone.

Treatment

should include antifungal medication.

The
 lesions will resolve with no intervention.

The
 back eruption is in a dermatomal distribution.
Educational Objective:
Characterize the presentation and benign course of pityriasis rosea.
Key point:
Pityriasis rosea is an exanthem of children and young adults that presents with a "herald patch"
on the trunk followed by lesions in a distribution resembling a Christmas tree. It requires
symptomatic treatment only.
Explanation:
Pityriasis rosea is a skin eruption found mostly in children and young adults. A "herald patch"
precedes the rash in 50% of cases. The macules appear on the trunk and proximal extremities in
a distribution that resembles a fir tree in shape. The eruption is usually asymptomatic, other
than mild itching; oral lesions may be present, but they are very rare.
No treatment is necessary for this condition because it will resolve in 8 to 12 weeks on its own.
The differential diagnosis includes tinea corporis, drug eruption, and secondary syphilis.
Dermatomal distribution of disease is more likely with herpes zoster virus infection. Although
the herald patch may be mistaken for tinea corporis, the lesion is unresponsive to antifungal
medication.
References:
Chuh A, Zawar V, Law M, Sciallis G. Gianotti-Crosti syndrome, pityriasis rosea, asymmetrical
periflexural exanthem, unilateral mediothoracic exanthem, eruptive pseudoangiomatosis, and
papular-purpuric gloves and socks syndrome: a brief review and arguments for diagnostic
criteria. Infect Dis Rep. 2012;4(1):e12.
Kliegman RM, Stanton B. Diseases of the epidermis (chapter 657). In: Kliegman RM, et
al. Nelson Textbook of Pediatrics. 20th ed., 2016:3160-3168.
Question 3
Edited: Dec 20, 2018
Report Question
A child has developed a slowly spreading, scaly plaque on her face (see Figure).
Figure.
She sleeps with her cat, which has been scratching itself lately.
Which of the following is the most likely diagnosis?

eczema


tinea

faciei

psoriasis


seborrheic

dermatitis
Educational Objective:
Differentiate tinea faciei from other facial dermatologic conditions.
Key Point:
Tinea faciei presents with scaly papules that can develop into a well-demarcated, annular, scaly
plaque.
Explanation:
This patient has a well-demarcated plaque with scaling; because of those characteristics, this
lesion is in the papulosquamous category. The differential diagnosis of papulosquamous lesions
includes psoriasis, pityriasis rosea, parapsoriasis (mycosis fungoides), lichen planus, secondary
syphilis, lupus erythematosus, and fungal (dermatophyte) infections.
Eczema is poorly demarcated with epithelial disruption. Psoriasis usually presents with silvercolored, scaly papules and plaques. Seborrheic dermatitis occurs as yellow-colored scaling
lesions in the scalp, eyebrows, nasolabial areas, beard, and behind the ears.
Dermatophyte skin infections start as a scaly plaque that enlarges and with time may show
central clearing ("ringworm"). Organisms such as Microsporum canis are zoonotic, meaning
they can be spread from animals to humans, as in this case.
References:
Galbraith SS. Diseases of the dermis (chapter 659). In: Kliegman RM, et al. Nelson Textbook of
Pediatrics. 20th ed., 2016:3175-3185.
Kliegman RM, Stanton B. Diseases of the epidermis (chapter 657). In: Kliegman RM, et
al. Nelson Textbook of Pediatrics. 20th ed., 2016:3160-3168.
Question 4
Edited: Dec 20, 2018
Report Question
An 11-year-old boy presents to you with the focal hair loss seen in the Figure.
Figure.
The hair loss was first noticed about 5 to 6 weeks ago. The child's father tells you that he has
been losing his hair over the past 5 years.
The area of hair loss is highly pruritic in the child. His hair is not falling out in clumps. There is no
history of psychiatric disease. The area of hair loss does not appear to come and go.
Which of the following is the most likely diagnosis?

alopecia

areata

telogen

effluvium

trichotillomania


tinea

capitis
Educational Objective:
Diagnose tinea capitis.
Key point:
Tinea capitis presents with scaly, pruritic areas of hair loss containing black dots that are hairs
broken off at follicle.
Explanation:
This patient has tinea capitis, which may be associated with hair loss and a pruritic scalp. It is
not classically associated with lesions that are transient, nor does hair fall out in clumps.
Trichotillomania is distinguished from other forms of hair loss when a history of anxiety or
obsessive-compulsive disorder is present. Alopecia areata may be associated with waxing-andwaning hair loss patterns. Telogen effluvium is classically associated with hair falling out in
clumps.
Reference:
Martin KL. Disorders of hair (chapter 662). In: Kliegman RM, et al. Nelson Textbook of Pediatrics.
20th ed., 2016:3192-3197.
Question 5
Edited: Dec 20, 2018
Report Question
A mother presents to you after she saw lesions on her child's hands that she says has been
present for the last 2 months (see Figure).
Figure.
The mother tells you that her other daughter has similar lesions on her hands.
Which of the following is the most likely diagnosis?

verruca

vulgaris

sebaceous

nevus

dermoid

cysts

psoriasis

Educational Objective:
Recognize the presentation of verruca vulgaris.
Key point:
Cutaneous warts (verruca vulgaris) are distinguished by punctate capillaries when superficial
keratotic layer is pared down, and they are caused by human papillomavirus infection.
Explanation:
This is a classic example of verruca vulgaris, also known as warts, which is a common skin
growth caused by human papillomavirus infection. It is characterized by a verrucous
appearance or a rough, grayish surface. The superficial keratotic layer can be pared away,
revealing punctate capillaries, which are distinctive. First-line treatments are either cryotherapy
or topical salicylic acid
Psoriasis is not generally associated with the skin disease seen in warts. It often presents with
raised, circular lesions with a keratinized surface. Sebaceous nevus often presents as solitary
lesions that are smooth, circular, or linear and as hairless patches. Dermoid cysts are most
often skin-colored, solitary, and present as a small lump beneath the skin.
Reference:
Moscicki A. Human papillomaviruses (chapter 266). In: Kliegman RM, et al. Nelson Textbook of
Pediatrics. 20th ed., 2016:1618-1622.
Question 6
Edited: Dec 20, 2018
Report Question
At a well-child visit, you notice a dark lesion on the patient's leg (see Figure).
Figure.
The mother tells you that it was been present since birth. The lesion covers the patient's entire
ankle.
Which of the following is the most worrisome risk associated with this type of lesion?

development

of melanoma

development

of valvular heart disease

bleeding


developmental

delay
Educational Objective:
Identify the risk associated with large congenital nevi.
Key point:
Large congenital nevi have a 2% to 5% risk of developing malignant melanoma.
Explanation:
This child has a distinctive pigmented nevus, which is called a congenital nevus. These types of
nevi often cover the trunk and include the upper and lower back. Congenital nevi are present at
birth and have an increased risk of developing into malignant melanoma, particularly those
over the axial skeleton and posterior scalp.
The overall risk of melanoma in large congenital nevi is estimated to be 2% to 5%. The
development of melanomas in giant nevi usually occurs before puberty during the first 5 years
of age. In small and medium nevi, development routinely occurs after puberty.
Treatment consists of surgical removal, in stages, and often with grafting. Removal of a rapidly
changing nevus (size, color, or symmetry) is warranted.
References:
Yun SJ, Kwon OS, Han JH, et al. Clinical characteristics and risk of melanoma development from
giant congenital melanocytic naevi in Korea. Br J Dermatol. 2012;166:115-123.
Question 7
Edited: Dec 20, 2018
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A 1-day-old male neonate is found to have tiny white blisters on his face on examination. He
was born at 36 weeks via spontaneous vaginal delivery without complication. His mother
received no prenatal care. Her physical examination during delivery was normal, she denies any
significant past medical history, and her prenatal laboratory results are pending.
The neonate has been breastfeeding well and has had 2 wet diapers and 1 meconium stool. His
vital signs have been normal since delivery.
On examination, he is sleeping comfortably. He has 1 to 2 mm white cysts scattered over his
nose, cheeks, and forehead. His lungs are clear; he has no murmur and no organomegaly. The
rest of the examination is normal.
The Figure demonstrates the lesions seen on his face.
Figure. Reproduced from Sadana DJ, Sharma YK, Chaudhari ND, Dash K, Rizvi A, Jethani S. A
clinical and statistical survey of cutaneous changes in the first 120 hours of life. Indian J
Dermatol. 2014;59(6):552-557.
What should be done at this time?

routine

monitoring

topical

steroids

lumbar

puncture (LP)

intravenous

acyclovir
Educational Objective:
Describe the management of milia in a neonate.
Key Point:
Milia is a normal rash found on neonates that self-resolves in several weeks and does not
require medical intervention.
Explanation:
This healthy neonate appears to have milia, which is a benign newborn rash. It is caused by the
cystic retention of keratin in the superficial epidermis. The cysts are called Epstein pearls when
they are present in the oral cavity. They normally resolve spontaneously during the first few
weeks of life.
All neonates with rashes should be closely examined to rule out serious disease. Although this
child’s mother had no prenatal care, there are no concerning issues on examination. A full
diagnostic workup of the neonate would be required if the mother had active herpetic lesions
or if the infant showed signs of poor feeding, lethargy, or fever. The lesions of herpes generally
show up later, at around 9 to 11 days of life. LP and cerebrospinal fluid analysis may assist in
the diagnosis of neonatal herpes simplex virus (HSV) infection. Treatment of HSV involves
intravenous acyclovir.
Topical steroids may be warranted in those with lesions consistent with eczema and infantile
acropustulosis.
References:
Gehris RP, et al. Dermatology (chapter 8). In: Zitelli BJ, et al. Zitelli and Davis' Atlas of Pediatric
Physical Diagnosis. 7th ed., 2018:275-340.
Martin KL. Diseases of the neonate (chapter 647). In: Kliegman RM, et al. Nelson Textbook of
Pediatrics. 20th ed., 2016:3116-3118.
Sadana DJ, Sharma YK, Chaudhari ND, Dash K, Rizvi A, Jethani S. A clinical and statistical survey
of cutaneous changes in the first 120 hours of life. Indian J Dermatol. 2014;59(6):552-557.
Question 8
Edited: Dec 20, 2018
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A 10-day-old boy with lethargy and small vesicles on an erythematous base on his head. He was
born at 38 weeks of gestation via spontaneous vaginal delivery to a 16-year-old woman.
The neonate was bottle-feeding well up until yesterday. Since then, he has seemed sluggish. He
has been sleeping more and has had fewer wet diapers.
On examination, his vital signs are normal. He is difficult to arouse, and he does not seem
interested in a bottle, although his mother says the last time he ate was 6 hours ago. He has a
patch of erythematous grouped vesicles about 5 to 6 mm in size on top of his scalp. His eyes,
nose, and pharynx are free of sores. His lungs are clear, he has no murmur, no jaundice, and no
organomegaly. The rest of the examination is normal.
What should be performed at this time?

biopsy

of a blister and await pathology results over the weekend

start

acyclovir and ask them to return after the weekend for follow-up

close

monitoring with 24-hour follow-up care

refer

for further workup, hospital admission, and treatment
Educational Objective:
Describe the management of neonatal herpes simplex virus infection.
Key Point:
The differential of dermatologic disease with neurologic symptoms in a neonate should include
herpes simplex virus (HSV) infection. The severe disease sequelae associated with HSV infection
mandates urgent diagnostic evaluation and treatment.
Explanation:
This neonate presents with lethargy, poor feeding, and skin lesions that could be associated
with herpes simplex virus (HSV) infection. Thus, he should be referred for hospital admission for
diagnosis and further workup to rule out disseminated or central nervous system (CNS)
infection. Urine, stool, cerebrospinal fluid (CSF), and eye and throat specimens should be sent
for culture. Biopsy of the blister should be performed and the sample sent to a pathologist.
Neonatal localized manifestations of HSV infection commonly appear in the mouth, eyes, or on
the skin. Skin lesions occur at the site of inoculation, such as where scalp electrodes cause skin
trauma.
Treated neonates/infants with localized disease have a high survival rate. Those with CNS or
disseminated infection have much higher mortality rates. The workup will entail lumbar
puncture due to the CNS manifestations. Based on an analysis of the CSF, treatment with an
antiviral medication can be initiated to target the suspect HSV infection. Acyclovir should not be
initiated until diagnostic studies have been obtained. Given the morbidity associated with HSV
infection, monitoring without intervention is not recommended.
References:
James SH, Kimberlin DW. Neonatal herpes simplex virus infection. Infect Dis Clin North Am.
2015;29(3):391-400.
Stanberry LR. Herpes simplex virus (chapter 252). In: Kliegman RM, et al. Nelson Textbook of
Pediatrics. 20th ed., 2016:1572-1579.
Question 9
Edited: Dec 20, 2018
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A 2-day-old female neonate is found to confluent erythematous macules and papules with
centralized pustules on examination. She was born at 39 weeks via cesarean delivery. Her
mother received routine prenatal care and has a history of giving birth to a previous child via
cesarean delivery.
The infant has been breastfeeding well and has had 3 wet diapers and 1 meconium stool. Her
vital signs have been normal since delivery.
On examination, she is sleeping comfortably. She has macules 2 to 3 cm in size with central
vesicles 1 to 2 mm in size scattered over her face, trunk, arms, and legs. She has no jaundice.
Her lungs are clear; she has no murmur and no organomegaly. The rest of the examination is
normal.
The Figure illustrates the appearance of the dermatologic lesions.
Figure. Image courtesy of RegionalDerm.com.
A smear of a vesicle would predominantly show which of the following?

multinucleated

giant cells

hyperkeratosis


polymorphonuclear

leukocytes

eosinophils

Educational Objective:
Recognize the physical manifestations of erythema toxicum neonatorum.
Key Point:
A major diagnostic feature of erythema toxicum neonatorum, which is a benign, self-limiting
condition, is the presence of eosinophils in the lesions. The lesions will resolve without
treatment.
Explanation:
This healthy girl appears to have erythema toxicum neonatorum, which is a benign rash seen in
neonates. The cause is unknown, but the eosinophil response is suggestive of hypersensitivity
reaction. Lesions may occur from birth and up to 10 days of life, and individual lesions clear
within 5 days. No treatment is necessary.
All neonates with rashes should be closely examined to rule out serious disease. No serious
concerns were seen during examination. A full diagnostic workup would be required if the
neonate showed signs of poor feeding, lethargy, or fever.
Hyperkeratosis may be seen in such skin diseases as sucking blisters and epidermolytic
hyperkeratosis. Pustules associated with transient neonatal pustular melanosis contain
polymorphonuclear leukocytes. Multinucleated giant cells can be seen in viral lesions secondary
to herpes simplex and varicella zoster virus infections.
References:
Gehris RP, et al. Dermatology (chapter 8). In: Zitelli BJ, et al. Zitelli and Davis' Atlas of Pediatric
Physical Diagnosis. 7th ed., 2018:275-340.
Haveri FT, Inamadar AC. A cross-sectional prospective study of cutaneous lesions in
newborn. ISRN Dermatol. 2014;2014:360590.
Martin KL. Diseases of the neonate (chapter 647). In: Kliegman RM, et al. Nelson Textbook of
Pediatrics. 20th ed., 2016:3116-3118.
Question 10
Edited: Dec 20, 2018
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A 1-day-old female neonate is found to have a rash above her left eye on examination. She was
born at 40 weeks via spontaneous vaginal delivery requiring vacuum assistance. The neonate
required blow-by oxygen upon delivery.
The neonate has been bottle-feeding well and has had 2 wet diapers and 1 meconium stool.
Her vital signs have been normal since the delivery.
On examination, she is sleeping comfortably. She has dull pink macules 0.5 cm in size on her
glabella, eyelids, and upper lip. She also has left-sided cephalohematoma. There is no
conjunctivitis or eyelid edema, and her extraocular movements are intact. She has no jaundice.
Her lungs are clear; she has no murmur and no organomegaly. The rest of the examination is
normal.
The Figure demonstrates the appearance of the dermatologic lesions.
Figure.
What is the probable course of the facial lesions?

no
 change in size or color over time

deepening

and enlarging within 3 years, requiring laser therapy for complete resolution

fading

almost completely within 3 weeks

fading

almost completely within 3 years
Educational Objective:
Recognize the course of action of nevus simplex (salmon patch).
Key Point:
Nevus simplex or salmon patch occur commonly over the face and self-resolve by 3 years.
Explanation:
This vascular lesion is a salmon patch, which is thought to be due to a persistence of fetal
circulation. These lesions are asymptomatic and benign, and they tend to fade within a few
years. Other common locations are the nape of the neck and the forehead.
Hemangioma is a benign vascular proliferation that rapidly enlarges during the first year and
spontaneously involutes by 2 or 3 years of age. Superficial hemangiomas are bright red with a
nodular consistency and are called strawberry hemangiomas. Deeper ones are purple and
called cavernous hemangiomas.
A port wine stain is a macular vascular patch made of dilated blood vessels. It is typically benign
but can be associated with other abnormalities and syndromes.
All neonate with rashes should be closely examined to rule out serious disease. The vacuum
extraction yields the possibility of local bruising and damage to the head and face. Further
workup of the neonate would be required if she showed signs of eye injury.
References:
Gehris RP, et al. Dermatology (chapter 8). In: Zitelli BJ, et al. Zitelli and Davis' Atlas of Pediatric
Physical Diagnosis. 7th ed., 2018:275-340.
Haveri FT, Inamadar AC. A cross-sectional prospective study of cutaneous lesions in
newborn. ISRN Dermatol. 2014;2014:360590.
Martin KL. Diseases of the neonate (chapter 647). In: Kliegman RM, et al. Nelson Textbook of
Pediatrics. 20th ed., 2016:3116-3118.
Question 11
Edited: Dec 20, 2018
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A 5-day-old male neonate presents to you for a newborn check. His mother says that he is
bottle-feeding well, sleeping 3 to 4 hours at a time, and has regular wet diapers and bowel
movements. However, she is concerned about a blue-grey pigmented macule on his lower back
(see Figure).
Figure.
She cannot recall any trauma in the past few days. She has been with her child most of the
time, except for a few hours when her boyfriend, who is not the baby’s father, to give her a
break.
The infant was born at 38 weeks via spontaneous vaginal delivery without complication. His
medical records indicate that his birth had a routine hospital course. The newborn examination
documents the discoloration at birth.
The baby is gaining weight well. Today he is sleeping comfortably. He has a blue-black macular
area measuring 5 cm over the lumbosacral area. He has no jaundice. His lungs are clear; he has
no murmur and no organomegaly. The rest of the examination is normal.
What should be done at this point?

Inform

the mother that the discoloration will probably disappear by 12 years of age.

Inform

the mother that the discoloration will most likely require laser removal.

Call
 the proper authorities to report possible abuse.

Inform

the mother that the discolored area should be closely monitored for malignant transformatio
Educational Objective:
Recognize the clinical presentation and natural history of Mongolian spots.
Key Point:
Dermal melanocytosis, or mongolian spots, are benign blue or gray macular lesions that usually
self-resolve by 12 years of age.
Explanation:
This infant has a Mongolian spot over his lumbosacral area. Mongolian spots develop in utero
and are most noticeable at birth. They are asymptomatic. In approximately one-half of cases,
Mongolian spots disappear within the first year of life, and most of those remaining resolve by
10 to 12 years of age.
Malignant degeneration does not occur. The lesions can be distinguished from child abuse
based on their congenital onset and their appearance as blue or grey colored lesions with
variably defined lesions. Laser removal is possible in the small percentage of cases where the
lesions persist.
References:
Carrasco MM, Wolford JE. Child abuse and neglect (chapter 6). In: Zitelli BJ, et al. Zitelli and
Davis' Atlas of Pediatric Physical Diagnosis. 6th ed., 2012:171-235.
Gupta D, Thappa DM. Mongolian spots – a prospective study. Pediatr Dermatol 2013,
30(6):683-688.
Haveri FT, Inamadar AC. A cross-sectional prospective study of cutaneous lesions in
newborn. ISRN Dermatol. 2014;2014:360590.
Kane K, et al. Color Atlas and Synopsis of Pediatric Dermatology. 2nd ed., 2002:178-179.
Martin KL. Diseases of the neonate (chapter 647). In: Kliegman RM, et al. Nelson Textbook of
Pediatrics. 20th ed., 2015:3116-3118.
Question 12
Edited: Dec 20, 2018
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A 6-year-old boy has eczema. He has inflamed, dry, and pruritic areas on his face, trunk, and
extremities. He is initially treated with moisturizers and topical hydrocortisone 2.5%. With
those measures, he improves, but the itchy, dry erythema on his face persists. Which of the
following would be the next step in treating his facial eczema?

phototherapy


tacrolimus

topically

group

IV topical steroids

cyclosporine

systemically
Educational Objective:
Manage eczema in children.
Key Point:
Topical calcineurin inhibitors such as tacrolimus or pimecrolimus are second-line therapies in
children not responding to emollients or low-potency topical steroids.
Explanation:
Initial measures for treating eczema include emollients, hygiene, and low potency steroids.
Patients not responding to initial therapies could be advanced to topical calcineurin inhibitors
such as tacrolimus or pimecrolimus. In particular, topical calcineurin inhibitors are acceptable
for facial use, where higher potency steroids would be avoided.
The topical calcineurin inhibitors have included a warning about a possible link to lymphoma
development, although the risk is likely small.
In areas other than the face and skin folds, more potent steroids could be considered.
Phototherapy and oral cyclosporine are not used in children for safety reasons. However, they
are both options in adults.
References:Eichenfield LF, Tom WL, Berger TG, et al. Guidelines of care for the management of
atopic dermatitis: section 2. Management and treatment of atopic dermatitis with topical
therapies. J Am Acad Dermatol.2014;71(1):116-132.
Schneider L, Tilles S, Lio P, et al. Atopic dermatitis: a practice parameter update 2012. J Allergy
Clin Immunol. 2013;131(1):295-9.e1-27.
Tollefson MM, Bruckner AL; Section on Dermatology. Atopic dermatitis: skin-directed
management. Pediatrics. 2014;134(6):e1735-e1744.
Question 13
Edited: Dec 20, 2018
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A 15-year-old girl has had acne for 1 year. Initially, she had open and closed comedones, and
she was treated with topical adapalene. She returns because she feels that, while she initially
improved, in recent months her condition has worsened. On examination, she has some open
comedones but also many erythematous papules and several pustules. She is otherwise healthy
and not taking any medications. Which of the following is the most suitable next step in her
acne treatment?

isotretinoin

therapy

oral
 doxycycline in combination with topical benzoyl peroxide and topical adapalene

phototherapy

with ultraviolet light

oral
 cephalexin combined with topical clindamycin
Educational Objective:
Summarize the effective management of moderate to severe inflammatory acne.
Key Point:
Inflammatory acne is treated with topical antibiotics and retinoids, and oral antibiotics (usually
tetracyclines) are added for more severe disease.
Explanation:
This boy has moderate to severe inflammatory acne, and it should be treated with a
combination of oral antibiotics, topical antibiotics, and topical retinoids.
The presence of inflamed papules and pustules indicates that there is inflammatory acne.
Acne is treated in a step-wise fashion. Comedonal acne is treated with topical retinoids. For
mild inflammatory acne, topical benzoyl peroxide or topical antibiotics are added to topical
retinoid therapy. For moderate to severe inflammatory acne, oral antibiotics are added, usually
tetracyclines.
Oral cephalexin has not been shown to be particularly effective for acne and may promote a
shift toward methicillin-resistant Staphylococcus aureus.
Ultraviolet light is not used for treating acne.
Isotretinoin therapy is not a first-line therapy and is a severe teratogen with other serious
potential side effects, including depression and suicide.
References:Eichenfield LF, Krakowski AC, Piggott C, et al; American Acne and Rosacea Society.
Evidence-based recommendations for the diagnosis and treatment of pediatric acne. Pediatrics.
2013;131( Suppl 3):S163-S186.
Zaenglein AL, Pathy AL, Schlosser BJ, et al. Guidelines of care for the management of acne
vulgaris. J Am Acad Dermatol. 2016;74(5):945-73.e33.