OS 212 [B]: Locomotion and Sensation - Dermatology
1
Lec 03: Eczema and Dermatitis
March 17, 2014
Dr. Cynthia P. Ciriaco-Tan
OUTLINE
I. Introduction
II. Histologic Features
III. Exogenous Dermatitis
A.
B.
C.
D.
E.
Irritant Contact Dermatitis
Allergic Contact Dermatitis
Photodermatitis
Signs and Symptoms of Contact Dermatitis
Diagnosis of Contact Dermatitis
Table 1. Classification of Eczema/Dermatitis
EXOGENOUS
ENDOGENOUS
Irritant Contact
Dermatitis
Allergic Contact
Dermatitis
Photodermatitis
o Phototoxic
o Photoallergic
UNCLASSIFIED
Atopic dermatitis
Seborrheic
Dermatitis
Nummular
Dermatitis
Dishydrotic Eczema
Static Dermatitis
Asteatotic
Eczema
Neurodermatitis/
Lichen Simplex
Chronicus
Prurigo Nodularis
IV. Endogenous Dermatitis
A.
B.
C.
D.
E.
Atopic Dermatitis
Seborrheic Dermatitis
Nummular Dermatitis
Dishydrotic Dermatitis
Static Dermatitis
V. Unclassified
A. Asteatotic Eczema
B. Neurodermatitis
C. Prurigo Nodulari
VI. Differential Diagnosis
VII. Management
I. INTRODUCTION
 Ekzein – AD 543, Greek. “to boil out” or to “effervesce”
 A layman’s term; medical term is DERMATITIS
 Pruritic papulovesicular process associated with:
o Acute: erythema, vesiculation, weeping, edema
o Chronic: thickening, lichenification, scaling
 Both lichenification and thickening may be caused by scratching;
however, lichenification involves accentuation of skin lines
 Can either be exogenous, endogenous, or unclassified
 Skin inflammation with characteristic clinical and histologic features
From Fitzpatrick:
 Eczema/Dermatitis is a polymorphic inflammatory reaction pattern
involving the epidermis and dermis.
 Acute: pruritus, erythema and vesiculation
 Chronic: pruritus, xerosis, lichenification, hyperkeratosis +
fissuring.
II. HISTOLOGIC FEATURES
 Acanthosis: epidermal thickening and/or widening
 Spongiosis: edema and serous exudate between epidermal cells
 Exocytosis: upward movement of lymphocytic/mononuclear infiltrate
in superficial dermis and epidermis
 Subcorneal pustule (neutrophils and bacteria)  secondary
impetignization; not always present
o Presence of PMNs - signals infection (encircled)
III. EXOGENOUS DERMATITIS
 Caused by external factors and/or substances
A. IRRITANT CONTACT DERMATITIS
 Reaction to chemical in a potent concentration in a sufficient
length of time
 Develops at site of contact
 No allergic mechanism
(instant appearance)
 More common type of
contact dermatitis
 Damage results from
direct chemical actionimmediate reaction
 Provoking substances
o Strong/absolute irritants
 Acids/ alkalis
 Metallic elements,
salts
 Essential oils
Figure 2. Irritant contact
o Weak/mild irritants
dermatitis
 Detergent
 Organic solvent
 Excessive water exposure
B. ALLERGIC CONTACT DERMATITIS
 First contact with allergen: Sensitization occurs within a few weeks to
months after but NO visible skin changes
 Subsequent contact: presentation of dermatitis
 May persist for months, years, or
forever (due to sensitization)
 Delayed type hypersensitivity
(Type IV) - mediated by Tlymphocytes (memory); may
persist forever
 Education is important so patients
can avoid inciting factors
 Named according to:
o Inciting factors/allergens
o Location of eczema
INCITING FACTORS/ALLERGENS
Figure 3. Allergic contact
dermatitis due to earrings
 Plant dermatitis - distinguished by its linear configuration
 Metal dermatitis - caused by nickel; gold jewelry < 18 carat, gold
jewelry > 20 carats recommended
 Other types - Clothing, footwear, cosmetic, topical medication,
occupational dermatitis
A
Figure 1. Histologic features of eczema
REMEMBER: Regardless of etiology, eczema will have similar chronic
histologic features:
 Hyperkeratosis
 Irregular acanthosis of epidermis
 Thickening of collagen bundles in papillary dermis (scar)
B
Figure 4. A Metal dermatitis. B Plant dermatitis is linear and
almost vesicular. C Footwear dermatitis. In the US, the Society for
Contact Dermatitis identifies the contactant of the year.
A
Lichen Simplex Chronicus (LSC) – end stage of any eczema
CARA, ANJ, NAOMI
C
A
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Lec 03: Eczema and Dermatitis
LOCATION OF ECZEMA
 Nipple eczema – usually bilateral, in the young and with family history
of the family. It is differentiated from Paget’s disease of the breast
(unilateral presentation).
 Ear eczema
 Eyelid dermatitis – commonly caused by nail lacquer
 Diaper dermatitis – spares the skinfolds. Differentiated from
candidiasis (reverse).
 Hand eczema
 Mucous membrane dermatitis
Figure 5. Diaper dermatitis
Table 2. Irritant vs. Allergic Contact Dermatitis (Fitzpatrick)
ICD
ACD

Occurs after a single

Dependent on sensitization
exposure to a an offending 
Occurs only in sensitized
agent that is toxic to skin
individuals

Dependent on

Minute amounts can elicit
concentration (threshold)
a reaction

Occurs in everyone

Immunologic reaction that
(depends on the
involves the surrounding
penetrability and thickness
skin (spreading
of the stratum corneum)
phenomenon) and may

Confined to the area of
generalize
exposure (sharply
marginated)
C. PHOTOCONTACT DERMATITIS
 Eruption caused by sensitization due to sun-activated irritant/
allergen, as in a medicine,
e.g. clindamycin,
tetracycline, doxycycline
 Usually in sun-exposed
areas
 Two types:
o Phototoxic- counterpart
of irritant contact
dermatitis
o Photoallergiccounterpart of allergic
contact dermatitis
 Make sure it’s just
photoallergy- inner sides of
arms are not exposed to the
sun, hence not involved
D. SIGNS AND SYMPTOMS OF CONTACT DERMATITIS
 Always has pruritus- if it’s eczematous but not pruritic, think twice!
 Stages
o Acute- erythema, edema, papules, vesicles, bullae (occasionally)
o Subacute - dull erythema, minimal edema, vesiculation, crusting
o Chronic - LSC; dry, lichenified scaly patches, occasional fissures
 May also be acneiform, with hyperpigmentation and purpura
 Can distinguish this from acne by checking if lesions are
monomorphic: all lesions are of the same size, same
appearance
 You can have all stages at one point.
E. DIAGNOSIS OF CONTACT DERMATITIS
 Before doing a Patch Test, do
History and PE first to close in
on the diagnosis, as the test can
be expensive. (PGH: P 3000;
elsewhere: P 8000)
 Take the history - course of
eruption
 Physical examination locat
Figure 7. Patch Test
ion,
Cara, Anj, Naomi
OS 212
pattern, regional clues, morphology
 Patch test
o “application of specific allergens directly to the skin under controlled
conditions, causing a local allergic reaction in a susceptible
(sensitized) person (Ale & Maibach, 2010)
o Wells/cells of the patch have corresponding chemicals. Allergens
are placed in a chart. This will be placed on the skin for 2 days,
then check and see where it lights up (reaction occurred).
IV. INTERLUDE: Are you having fun? :)
ENDOGENOUS DERMATITIS
 Caused by reactions of the body to self-molecules
A. ATOPIC DERMATITIS
 Known as Besnier’s prurigo, neurodermatitis disseminata
 More commonly seen in Asians
 Appear as lichenified plaques
 Usually found in the antecubital and popliteal areas, neck, and
cheek; chronic; hardly found in the acute stage, when found in the
acute stage, they usually generalize
 Patients with atopic dermatitis usually have personal or family history
of asthma, urticarial or hay fever
 Genetic predisposition
o Increased IgE-mediated immune responses in early stages;
defective T-cells in later stages
o Defect in filaggrin gene encoding for filament aggregating protein
involved in establishing epidermal barrier function (Sajić,
Asiniwasis, & Skotnicki-Grant, 2012)
o Atopic skin becomes like a sieve where allergens enter
 Essential elements (3)
o Pruritus
o Chronicity/ relapsing course
o Characteristic eczema – area lesions appear on depends on stage
of atopic dermatitis (discussed later)
 Stages (3)
o Infantile – 2 months to 2 years; attacks on extensor areas,
o Childhood – 2-10 years old; attacks on flexural areas
 Babies below 1 y/o don’t know how to scratch. They just rub
against their cheeks when something feels good. As they age,
lesions are seen on the areas they can reach (flexural areas)
o Adult- localizes in antecubitals, popliteals (flexural areas), but
patients can have the reverse, i.e. lesions are still seen in the
extensor areas even in adulthood
 Associated conditions
o Keratosis Pilaris
 A lot of Filipinos present with this lesion
 Closely associated with skin asthma but can appear in nonasthmatics
 Autosomal dominant- when your mother or father has it,
chances are you have it
 Around 10 % of atopics are said to have this
o Pityriasis Alba
 reddish rough patch becoming hypopigmented through time
 Ddx
- Pityriasis Vesicolor- determined by KOH, fingernail test
- Leprosy- Touch sensation test will not work for kids (they
feel or not, it’s the same for them). Let them play outside. If
they don’t sweat, positive for leprosy
Figure 8. Leprosy
B. SEBORRHEIC DERMATITIS
 Also known as seborrhea
 Yellowish or grayish, sharply marginated macules covered with
greasy scales
 Macules or papules coalesce to form irregular patches
 Commonly found in seborrheic areas- areas of greater sebaceous
activity such as: scalp, eyebrow, nasolabial area, pre- and postauricular areas, axillae, interscapular area, chest, back, groin
 Unknown etiology
 Factors
o Stress- lack of sleep, Med school, Derma exam and OSCE
o Hypertension, Diabetes, High Cholesterol
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Lec 03: Eczema and Dermatitis
o HIV- earliest dermatologic
symptom is seborrhea
o Infection- asymptomatic UTI
o Change in weather
o Alcohol intake
Figure 9. Seborrhea on
the nasolabial area
A. NUMMULAR DERMATITIS
 Also known as discoid eczema
 Coin-shaped and eczematous
 Discrete, erythematous, edematous,
papulovesicular plaques
 Most commonly found in the legs and arms
(back of the hands and fingers)
 Unknown etiology
o Simple insect bites, scratches and wounds
may develop into nummular dermatitis
Figure 10. Nummular dermatitis
B.
DYSHIDROTIC DERMATITIS
 Also known as dyshidrosis, cheiropompholyx, pompholyx
 Recalcitrant, deep-seated vesicular eruptions on the palms and
B.
OS 212
NEURODERMATITIS
 Also known as Lichen Simplex Chronicus
(LSC) - end stage of any eczema
 Due to stress or habit of scratching/ rubbing
 Common in med students, they find a place
to pick at constantly
o When cause is unidentifiable, the lesions
are usually due to stress
 Single, fixed lichenified plaque
 Legs, forearms, anogenital areas - areas you
can reach
 In addition to treatment, STOP
scratching/touching the lesion
Figure 14. Lichen Simplex Chronicus
C. PRURIGO NODULARIS
 Hard nodules on proximal
limbs-reachable areas
 Caused by chronic scratching
or rubbing
 If one finger is used in
scratching, the result is
prurigo nodularis; if five
fingers are used, LSC
 Example is an insect bite that
you keep scratching
soles
 Described as “parang sago-sago sa daliri”
 Usually clear fluid, but gets easily infected when ruptured purulent
(turn into pustules)
 Location: acral (peripheral); lateral sides of fingers, palms, soles
 Simultaneous hyperhidrosis
 Ddx: tinea - important to differentiate due to difference in treatment
o Steroids: dyshidrotic dermatitis; Antifungals: tineas
Figure 11. Dyshidrotic dermatitis on dorsal side of hands
C.
STASIS DERMATITIS
 Varicose eczema - common among
adults and elderly
 Venous insufficiency  Pooling of





blood Varicosities Varicose
edema  Static dermatitis
Poor nutrition (deoxygenated blood)
leads to dryness, itchiness, and
edema
Chronic condition of lower leg,
especially in high heel wearers
o Check medial side (note
presence/absence of varicosities)
Accompanied by hemosiderin
deposition (dark spots) and
lipodermatosclerosis - thickening of
skin
Chronic wounds and frequent ulcer
formation due to poor blood perfusion
Differentiate from edema from
Figure 12. Static dermatitis
systemic causes by asking “Kailan
on lower leg
kayo minamanas?”
o Upon waking up: systemic
o Only in the afternoon: Venous insufficiency
V. UNCLASSIFIED DERMATITIS
A. ASTEATOTIC ECZEMA
 Xerotic eczema; winter dry skin, eczema
craquele (skin cracks)
 Common among elderly due to skin
dryness
 Dry skin, with redness, scaling, fine
crackling or fine superficial fissures
(“crazy paving”)
Figure 15. Prurigo Nodularis
VI. DIFFERENTIAL DIAGNOSES
 Fungal infection – has a clear center, advancing border with papules
and pruritus is not present all the time
 Tenia pedis – interdigital webs
 Psoriasis – with Auspitz’s sign, silvery scales but sometimes shows
as red papules so harder to differentiate from eczema
 Scabies – may present like eczema, but nocturnal pruritus is more
intense, interrupting sleepvery small lesions na di mukhang makati
 Pityriasis rosea
 Secondary syphilis – if you’re not sure what it is, DON”T TOUCH
o Primary is an ulcer in genital area. Secondary is associated with
bacteria and can manifest in various forms: copper colored
macules and papules; may appear as alopecia, nummular
dermatitis
 Drug reactions
 Erysipelas
 Icthyosis
 Acrodermatitis enteropathica – Zinc deficiency
 Histiocytosis X – bad case of seborrhea, it can present like a cradle
cap, should be spotted early. When you see a baby in the ward with
petecchial lesions on the soles and hands with hepatomegaly, think
HX
 Pellagra – Niacin deficiency
VII. MANAGEMENT
 Dressings – so that when you put steroids they won’t ooze out
 Dessicants – like alcohol
 Topical steroids – class 1-7, 7 weakest (e.g. Hydrocortisone), know





when to use ointments (oil-based, makes acute lesions weep more)
versus cream (for acute)
Oral Antihistamines – to stop nocturnal itching (atopic dermatitis)
Systemic steroids – to downregulate inflammation; use when acute
stage is worse
Immunomodulators – alternative to systemic steroids (ex. tacrolimus)
Ancillary
o Antibiotics
o Emollients – use for dry skin (atopic dermatitis and eczema
craquele)
Try to identify contactants, educate patients to avoid them and stop
scratching; otherwise, useless treatment
END OF TRANSCRIPTION
Cara: Hello to everyone, especially packmates Meggie, Anton, Kevin, Owa. Wala na palang IDC
so goodbye BSLR-W with seatmates Kei and the broken chair, plus backmates Bernette, Vince,
Danette. Goodbye CH222 with Jantan and backmates TheMurillo, Yan 2, JCP.
Anj: everything in graciousness and good faith
This is the trip. This is the best part of the trip. It’s gonna be wild. It’s gonna be great. You’re
gonna be stars. But dig it. We are never, ever gonna be this young again.
- Dito Montiel, A Guide to Recognizing Your Saints
Naomi: Summeeeeeerrrrrrr!
Figure 13. Asteatotic
eczema on the leg
Cara, Anj, Naomi
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