Prepared by:
DR. Salma El Gazzar
.Describe the different morphological types of rash
.Recognize the key component from the history and physical examination of a rash .
:List and discuss the common infectious causes of the following .
Vesicular rash
Macular skin rash
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Maculopapular rash
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Peticheal rash
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Purpuratic rash
.Outline the initial evaluation for skin rash
- Learning to recognize common skin conditions is a skill
that is extremely valuable in all areas of medicine.
- In pediatrics in particular it is important to have the
ability to identify skin lesions, as such knowledge will
enable you to both recognize potentially significant
systemic diseases, such as meningococcemia or chicken
pox, and reassure concerned parents.
The structure and function of the skin:
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The skin is composed of three different layers.
The outer most layer, the epidermis, is made predominantly
of keratinocytes.
The most superficial layer of the epidermis, the stratum
corneum, serves as a protective barrier against the
environment, and prevents desiccation.
The epidermis also plays a role in immune surveillance.
Damage to the epidermis increases skin permeability,
thereby increasing the risk of infection.
The epidermis also contains melanocytes (which gives the
skin its color), Merkel cells (which are pressure receptors),
and Langerhans cells (which participate in the skin's
immune response).
 The dermis lies beneath the basement membrane of the
epidermis.
 The dermis consists of collagen, elastin, and proteoglycans,
which lend support and durability to the skin.
 Blood vessels, lymphatics, sweat glands, hair follicles, smooth
muscle, and neuroreceptors are all found in the dermis.
 Fibroblasts in the dermis are responsible for collagen
production and are the predominant cell in this layer of the
skin.
 Other cells common in the dermis include mast cells,
leukocytes, and histiocytes.
 Subcutaneous tissue resides beneath the dermis.
 This layer serves as insulation, a fat depot, and a cushion
against trauma.
 Blood vessels and lymphatics are found in the subcutaneous
tissue as well as the base of hair follicles and sweat glands.
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Those lesions that are the direct result of a pathologic process.
Primary lesions are described as macules, patches, papules, nodules,
tumors, vesicles, bullae, pustules, plaques, cysts, and wheals.
A macule is a flat, circumscribed skin discoloration that is neither raised
nor depressed. It cannot be felt.
Once it reaches 1cm or greater in size, it is termed a patch.
A papule is an elevated, solid lesion that is less than 0.5cm in diameter.
If the diameter is greater than 0.5cm, it is known as a nodule.
A nodule is basically a larger, deeper papule.
Tumors are usually larger in diameter than nodules, and tend to be
variable in consistency and mobility.
Vesicles (blisters) are raised, fluid-filled lesions less than 0.5cm
in diameter.
 A bulla is a larger fluid-filled lesion that is greater than 0.5cm
in diameter.
A pustule is a papule that contains purulent material.
A plaque is an aggregation of papules, vesicles, or pustules that
is greater than 0.5cm in diameter.
Wheals are palpable, firm, edematous lesions that may vary in
configuration and size.
They tend to be pruritic and evanescent (existing briefly before
disappearing).
A cyst is a lesion that contains fluid or semi-solid material. Its
walls are circumscribed and thick, and it is
 Primary lesions may develop or turn into secondary lesions.
 Secondary lesions include crusts, scales, excoriations, fissures,
erosions, ulcers, and scars.
 Crusts (scabs) are dried collections of blood, serum, or pus.
 They usually arise from a primary lesion such as a vesicle, bulla,
or pustule.
 Scales consist of compressed layers of keratinocytes on the skin
surface.
 An excoriation is a linear erosion caused by scratching.
 A fissure is a crack in the skin.
 An erosion is a focal loss of epidermis that heals without
scarring.
 An ulcer is a focal loss of epidermis extending into the dermis
that heals with scarring.
 A scar is an end-stage lesion composed of connective tissue,
which may be atrophic or hypertrophic.
 A rash is a reaction of the skin.
 It can be caused by many things, such as a drug
reaction, an infection, or an allergic reaction.
 Many different agents can cause similar-appearing
rashes because the skin has a limited number of
possible responses.
 Very often the other associated symptoms or history,
in addition to the rash, help establish the cause of the
rash, such as a history of tick bites, exposure to other
ill children or adults, recentantibiotic use,
environmental exposures, or prior immunizations.
 Most rashes caused by viruses do not harm a child
and go away over time without any treatment.
 However, some childhood rashes have serious or
even life-threatening causes.
Initial assessment of the rash:
Are there any fluid filled vesicles?
Is the rash raised (papular) or flat (macular)?
Is the rash red?
Is the rash scaly?
Is the rash itchy?
When did the rash start?
Where did the rash start, and how did it spread?
History
 What is the past medical and drug history?
 Did the patient present with other symptoms
(e.g. fever, headache)?
 Has the patient been exposed to new topical
applications (e.g. soap, lotions)?
 Has the patient ingested any unfamiliar
foods?
 Has the patient had close contact with
someone else with the same symptoms?
 Has the patient travelled recently?
General examination
If a systemic illness is expected .
Examination of the skin
 Examine the whole skin, even if the rash
seems localized.
 Ensure that the patient is comfortable, with a
close caregiver nearby.
 A rash resulting from a topical application will
be present in a specific area (e.g. under arms,
nappy area).
 A rash resulting from a systemic cause will be
generalized and symmetrical. Systemic illness
may also present in the mouth (e.g. syphilis,
Differential diagnosis of vesiculobullous rash:
Clear fluid:
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Chickenpox (varicella)
Herpes simplex virus (HSV)
Hand foot and mouth syndrome
Impetigo
Staphylococcal scalded skin syndrome
Toxic epidermal necrolysis
Stevens Johnson syndrome
Erythema multiform
Promphoylx
Pustular:
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acne vulgaris.
Folliculitis
Pustular psoriasis
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The varicella-zoster virus, one of the herpes viruses,
causes chickenpox infection. The same virus that causes
chickenpox also causes shingles (herpes zoster).
it can spread easily. You can get it from an infected
person who sneezes, coughs, or shares food or drinks.
You can also get it if you touch the fluid from a
chickenpox blister.
The first symptoms of chickenpox include:
-A fever of 100.4°F (38°C) to103°F (39.4°C).
-Feeling sick, tired, and sluggish.
-Little or no appetite.
-Headache and sore throat.
The first symptoms are usually mild in children, these
symptoms may continue throughout the illness.
 A person who has chickenpox can spread the virus even before he or she
has any symptoms.
 Chickenpox is most easily spread from 2 to 3 days before the rash appears
until all the blisters have crusted over (7 days).
 The first symptoms of chickenpox usually develop about 14 to 16 days
(incubation period 2-3weeks) after contact with a person infected with the
virus. Most people feel sick and have a fever, a decreased appetite, a
headache, a cough, and a sore throat.
 About 1 or 2 days after the first symptoms of chickenpox appear, an
itchy rash develops.
 vesicles (initially papules, often not noticed), appearing as 'drops of water‘
“tear drop like”
 Superficial, thin-walled with surrounding erythema rapidly changing to
pustules and crusts.
 Appears in crops with all stages represented.
 First appears on the face and scalp and then spreads to the trunk and
extremities.
 It is centripetal in distribution.(heavy in trunk ,scarce on extremities)
 Crusts fall off in 1-3 weeks leaving a pink base. Initial fever is classically
high before becoming low-grade.
 Beware of dyspnea/cough which may indicate varicella-zoster virus (VZV)
pneumonitis.
- HSV-1 is the main cause of herpes infections on the
mouth and lips, including cold sores and fever blisters.
- It is transmitted through kissing or sharing drinking
glasses and utensils.
Signs and Symptoms
Small, painful, fluid-filled blisters around the lips or
edge of the mouth
Tingling or burning around the mouth or nose, often a
few days before blisters appear
Fever
Sore throat
Swollen lymph nodes in neck
herpetic whitlow is a lesion caused by the herpes simplex virus.
It is a painful infection that typically affects the fingers or thumbs.
Occasionally infection occurs on the toes or on the nail cuticle.
In children the primary source of infection is the orofacial area, and it is
commonly inferred that the virus (in this case commonly HSV-1) is
transferred by the chewing or sucking of fingers or thumbs.
Symptoms :
swelling, reddening and tenderness of the skin of infected finger. fever and
swollen lymph nodes.
Small, clear vesicles initially form individually, then merge and become
cloudy.
Associated pain often seems large relative to the physical symptoms. The
herpes whitlow lesion usually heals in two to three weeks.
Treatment :
Although it is a self-limited illness, oral or intravenous antiviral treatments,
particularly acyclovir, have been used in the management of
immunocompromised or severely infected patients.
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The most common cause of hand-foot-and-mouth disease is
infection with the coxsackievirus A16.
Oral ingestion is the main source of coxsackievirus infection
and hand-foot-and-mouth disease.
Symptoms:
Fever, Sore throat
Feeling of being unwell (malaise)
Painful, red, blister-like lesions on the tongue, gums and inside
of the cheeks
A red rash, without itching but sometimes with blistering, on
the palms, soles and sometimes the buttocks
Irritability in infants and toddlers
Loss of appetite
 The usual period from initial infection to the onset of signs and symptoms
(incubation period) is three to six days.
 A fever is often the first sign of hand-foot-and-mouth disease, followed by
a sore throat and sometimes a poor appetite and malaise.
 One or two days after the fever begins, painful sores may develop in the
mouth or throat.
 A rash on the hands and feet and possibly on the buttocks can follow
within one or two days.
Complications:
Dehydration , viral meningitis , encephalitis.
Treatment:
 There's no specific treatment for hand-foot-and-mouth disease.
 Signs and symptoms of hand-foot-and-mouth disease usually clear up in
seven to 10 days.
 A topical oral anesthetic may help relieve the pain of mouth sores.
acetaminophen (Tylenol, others) or ibuprofen (Advil, Motrin IB, others)
may help relieve general discomfort.
IMPETIGO
Contagious bacterial infection of epidermis
Can affect any skin region
Transmitted by direct contact with infected
persons or fomites
Primary impetigo: more common in children,
infection via minor breaks in skin
Secondary impetigo: any age, secondary
infection of trauma/wounds
Clinical diagnosis, confirmed by gram stain
or culture of crust or fluid from bullae
Clinical features:
Bullous impetigo
 Always caused by S. aureus,
 Can affect intact skin
 Vesicles and flaccid bullae (large vesicles) contain
clear yellow or slightly turbid fluid +/- surrounding
erythema
 Common in neonates and children <5 years
 Systemic symptoms common
Non-bullous impetigo
 More common than bullous
 Usually due to S. aureus or S. pyogenes
 Scattered discrete 1-3cm lesions with honey-coloured
crust and surrounding erythema
 Most common around mouth/nose
 Patients may have lymphadenopathy
TREATMENT:
 Local infections treated with
topical saline or aluminium
acetate, then 2% mupirocin
ointment
 If systemic symptoms present, use
beta-lactamase resistant antiobiotic
eg. Cephalexin
 If impetigo due to MRSA use
Clindamycin
Causes of Maculopapular Rash
Rubeola (Measles)
Rubella (German Measles)
Roseola (Exanthema Subitum)
Chikungunya Virus (Dengue)
Parvovirus B19 (Erythema Infectiosum or Fifth Disease)
Infectious Mononucleosis
Kawasaki disease
Drug Eruptions
Others (Cytomegalovirus (CMV), Salmonella typhi
(Typhoid Fever), Enteroviruses,etc.)
The cause of measles is a virus that replicates in the nose and
throat of an infected child or adult.
Clinical picture:
Prodromal stage (croyza, cough and conjunctivitis)
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Fever (38.5-40) tend to be highest just before the appearance
of rash)
Dry cough
Runny nose
Sore throat
Inflamed eyes (conjunctivitis)
Tiny white spots with bluish-white centers on a red
background found inside the mouth on the inner lining of the
cheek — also called Koplik's spots
The skin rash :
The rash consists of small red spots, some of which are slightly raised.
Spots and bumps in tight clusters give the skin a blotchy red appearance.
The face breaks out first, particularly behind the ears and along the hairline.
Over the next few days, the rash spreads down the arms and trunk, then over the
thighs, lower legs and feet.
 At the same time, fever rises sharply, often as high as 104 to 105.8 F (40 to 41 C).
 The measles rash gradually recedes, fading first from the face and last from the
thighs and feet
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Incubation period. 10 to 14 days
Communicable period. starting four days before the rash appears and ending when the
rash has been present for four days.
Complications :
Ear infection, Bronchitis, laryngitis or croup, Pneumonia, Encephalitis,Low platelet
count (thrombocytopenia).
Treatment:
Fever reducers. Antibiotics. Vitamin A.
Koplik's spots
- The cause of rubella is a virus .
- A person with rubella is contagious from 10 days before the
onset of the rash until about one or two weeks after the rash
disappears.
- An infected person can spread the illness before the person
realizes he or she has it.
The signs and symptoms of rubella typically last about two to
three days (3-day measles) and may include:
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Mild fever of 102 F (38.9 C) or lower
Headache
Stuffy or runny nose
Inflamed, red eyes
Enlarged, tender lymph nodes at the base of the skull, the back of the
neck and behind the ears
A fine, pink rash that begins on the face and quickly spreads to the trunk
and then the arms and legs, before disappearing in the same sequence
Aching joints, especially in young women
The most common cause of roseola is the human herpes virus 6,
but the cause also can be another herpes virus — human herpes
virus 7.
Fever. Roseola typically starts with a sudden, high fever — often
greater than 103 F (39.4 C). sore throat, runny nose or cough
along with or preceding the fever. The fever lasts three to five
days.
Rash. Once the fever subsides, a rash typically appears — but
not always ‘ THE RAINBOW FOLLOWING THE STORM’.
It consists of many small pink spots or patches which are
generally flat, but some may be raised.
The rash usually starts on the chest, back and abdomen and then
spreads to the neck and arms. It may or may not reach the legs
and face.
The rash last from several hours to several days before fading.
Erythema infectiosum is caused by infection
with PV-B19, a member of the Parvoviridae
family.
Signs and symptoms
Mild prodromal symptoms or even no prodrome (Headache , Fever, Sore
throat, Pruritus, Coryza, Abdominal pain, Arthralgia) begin approximately 1
week after exposure to PV-B19 and last 2-3 days.
These symptoms precede a symptom-free period of about 7-10 days, after
which the infection progresses through the following stages:
Phase 1 - The exanthem begins with the classic slapped-cheek appearance,
which typically fades over 2-4 days
Phase 2 - This phase occurs 1-4 days later and is characterized by an
erythematous maculopapular rash that fades into a classic lacelike reticular
pattern as confluent areas clear
Phase 3 - Frequent clearing and recurrences for weeks or occasionally months
may occur due to stimuli such as exercise, irritation, stress, or overheating of
the skin from sunlight or bathing in hot water
Cause
Erythrogenic toxin-producing strain of Group A betahaemolytic Streptococcus
Features
Incubation 2-4 days
Bright red blanching rash (sandpaper)
First in areas of warmth and pressure (neck , axillae, groins)
then widespread
Red face with circumoral pallor
Strawberry tongue (white then red)
Treatment
Symptomatic relief
Penicillin V 7-10 days
Kawasaki disease (mucocutaneous lymph node
syndrome) is an acute systemic illness characterized by
inflammation of the blood vessels (vasculitis).
The majority are age 5 years or younger, although
children of any age can get the disease.
The average age of a child with the illness is
approximately 2 years.
Boys are about 1.5 times as likely to develop Kawasaki
disease as girls.
signs and symptoms:
starting with a persistent high fever (101 degrees F to 104 degrees F) for at
least four days, along with four out of five of the following (WARM CREAM ):
1-changes in extremities
red, swollen palms of hands and soles of feet
peeling skin around the fingertips, hands or feet (occurs later in the illness)
2-non-specific rash on the body, often accentuated in the groin area
3-bloodshot eyes (no discharge)
4-redness in the lips, mouth and tongue
dry, red, cracked lips
inflamed, red mouth
swollen, red tongue (“strawberry tongue”)
5-swollen lymph node(s) in the neck (more than 1.5 cm), usually on one side
Other symptoms that may develop include:
arthritis-like symptoms (joint pain and swelling of the joints)
extreme irritability
diarrhea
vomiting
abdominal pain
enlarged liver or gallbladder
cough and respiratory symptoms
INVESTIGATIONS:
 elevated white blood cell count
 elevated liver function tests
 signs of inflammation in the blood and urine( ESR, positive
CRP, Sterile pyuria)
 Anemia
  platelets by day 10-14
 (ECG or EKG): a test that records the electrical activity of the
heart and shows abnormal rhythms.
 echocardiogram is a diagnostic tool that uses sound waves to
produce a moving picture of the heart and heart valves in order
to:
 measure the coronary arteries
 evaluate the structure and function of the heart muscle and
heart valves
TREATMENT:
 The principal goal of treatment for Kawasaki disease is to
prevent coronary artery disease and to relieve symptoms.
 Full doses of intravenous immunoglobulin (IVIG) are the
mainstay of treatment.
 Closely monitor cardiovascular function.
 High-dose aspirin for a variable period, followed by lowerdose aspirin for its antiplatelet effects.
 Aspirin is used in patients with small coronary artery
aneurysms (CAAs).
 Dipyridamole is indicated in patients with larger CAAs.
Description
Purpura : purplish discoloration of the skin
produced by small bleeding vessels near the surface.
Purpura may also occur in the mucous membranes,
especially of the mouth, and in the internal organs.
petechiae purpura spots that are very small (<1 cm
in diameter)
ecchymoses or bruising: Larger, deeper purpura
non-thrombocytopenic purpura :
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Congenital causes such as:
Hereditary haemorrhagic telangiectasia
Connective tissue diseases such as Ehlers-Danlos
syndrome
 Congenital cytomegalovirus (CMV) and congenital
rubella.
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Acquired causes such as severe infections
(eg meningococcal infections).
Allergic causes such as Henoch-Schönlein
purpura
Drug-induced causes such as steroids
Thrombocytopenic purpura :
 Impaired platelet production such as:
 Generalised (eg leukaemia, , myeloma, marrow
infiltration by solid tumours).
 Selective reduction in megakaryocytes (eg drugs such
as co-trimoxazole, chemicals, viral infections).
 Excessive platelet destruction such as:
 Immune problems (eg autoimmune
thrombocytopenic purpura, secondary immune
thrombocytopenia - SLE, viral infections, drugs - posttransfusion purpura).
 Coagulation problems (eg (DIC), thrombocytopenic
purpura,).
 Sequestration of the platelets as occurs in splenomegaly.
Meningococcemia is defined as dissemination of meningococci (Neisseria
meningitidis) into the bloodstream .
Patients with acute infection can present clinically with
(1)meningitis,
(2) meningitis with meningococcemia,
or (3) meningococcemia without obvious meningitis
Symptoms
There may be few symptoms at first. Some may include:
Fever
Headache
Irritability
Muscle pain
Nausea
Rash with red or purple spots develops in 75% of cases:
Initial rash that may be erythematous or maculopapulars, short lived,
followed by petechiae and purpura
Characteristic petechial skin rash, usually located on the trunk and legs.
Later symptoms may include:
-A decline in level of consciousness
-Large areas of bleeding under the skin.
-Shock.
Henoch-Schönlein purpura (HSP) is an acute
immunoglobulin A (IgA)–mediated disorder characterized by
a generalized vasculitis involving the small vessels of the
skin, the gastrointestinal (GI) tract, the kidneys, the joints,
and, rarely, the lungs and the central nervous system (CNS).
Signs and symptoms
The typical prodrome of HSP includes the
following(Headache ,Anorexia,Fever
Subsequently, symptoms develop, of which the following
are the most common:
Rash ,Abdominal pain and vomiting Joint pain, especially
involving the knees and ankles, Subcutaneous edema, Scrotal
edema Bloody stools
Skin findings (usually the first sign of HSP) :
 Erythematous macular or urticarial lesions,
progressing to blanching papules and later
to palpable purpura.
 typically symmetrical and tend distributed
in dependent body areas, such as the ankles
and lower legs in older children and adults
and the back, buttocks, upper extremities,
and upper thighs in young children; hives,
angioedema, and target lesions can also
occur
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Contact dermatitis can result from injury to the skin, as in
irritant dermatitis, or from a hypersensitivity response, as in
allergic dermatitis.
The distribution of the rash is determined by the points of
contacts.
Common hypersensitivity contact dermatitis allergens
include latex (rubber), nickel (jewelry, buckles, snaps), hair
dye and leather (tanning chemicals).
If a particular substance is suspected, a simple test to
confirm hypersensitivity is to tape a small piece of it on the
medial portion of the upper arm and observe for a reaction
12 hours later.
In the pediatric population, irritant dermatitis is more
commonly seen than allergic dermatitis.
Irritant dermatitis is an inflammation of the skin
caused by exposure to irritants such as soaps, saliva,
citrus juice, bubble baths, or detergents.
The appearance of the skin may range from mild
redness, edema, or vesicles to oozing bullae.
The face and hands may be affected by saliva from a
drooling infant.
Bubble baths may be the source of an intense pruritus.
Restrictive shoes that trap sweat and moisture may
cause irritant dermatitis of the feet.
Treatment of contact dermatitis may be as simple as
removing the irritant.
Hydrocortisone cream will provide additional relief.
Contact Dermatitis
DEFINITION:
 Diaper rash, or diaper dermatitis, is a general term describing
any of a number of inflammatory skin conditions that can
occur in the diaper area.
INCIDENCE:
 Diaper rash is the most common dermatitis found in infancy.
 Diaper rash occurs in approximately 50% of infants.
 The peak of incidence occurs between the ages of nine and
twelve months
ETIOLOGY:
 The main source of irritation is urine and feces on the skin.
 Diaper dermatitis may occur if diapers are not changed
frequently enough, or if the infant has diarrhea.
 However, it may occur even if diapers are changed regularly.
LOCATION AND DESCRIPTION:
 The buttocks, perineal area, lower abdomen and top of the
thighs are the areas that are most frequently involved.
 Characteristically, areas of flexure are spared.
 The rash appears erythematous, and the skin may look
scalded.
 Ulcers and erosions may be seen in severe cases.
TREATMENT:
 Diaper rash may be treated by frequent changes of diapers, at least every
three hours, and close attention to keeping the skin dry.
 Most cases are self-limited and resolve in 3 days.
 Petrolatum or zinc oxide may be used as a protective barrier.
 Severe cases may be treated with low potency topical corticosteroids.
 Diaper rashes may be complicated with a secondary Candida infection.
 Candida albicans can complicate any diaper rash that has been present for
three or more days.
 In these cases, the rash involves the skin flexures with satellite lesions.
These rashes may be treated with anti-candidal agents (e.g., clotrimazole,
miconazole and nystatin).
Greasy yellow scale on erythematous base
 Common on scalp, eyebrows, ears, diaper area &
in skin folds
 Affected regions may also develop fissures,
weeping & maceration
 May persist until 1 year of age
 Specific cause unknown
 Treatment
-mild case resolve with emollient
-scales treated with ointment contain
sulphur and salicylic acid
-Topical steroids
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Thank you