PEDIATRIC DERMATOLOGY 

Prepared by:DR. Salma El Gazzar

ObjectivesDescribe 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

  Maculopapular rash .

  Peticheal rash .

  Purpuratic rash .

 . Outline the initial evaluation for skin rash

Introduction- 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. 

Basic Understanding Of the Dermatology

The structure and function of the skin: 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.

SKIN LAYERS

CLASSIFICATIONS OF SKIN LESIONS

 primary lesion: 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

Secondary lesion: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.

COMMON PEDIATRICS SKIN RASHES.

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.

Assessment of dermatological rashes in a pediatric patient

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,

Summary of Paediatric Skin Rashes

Vesiculobullous rashesDifferential diagnosis of vesiculobullous rash:Clear fluid: 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: acne vulgaris. Folliculitis Pustular psoriasis

Chickenpox (varicella) 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.

Herpes simplex

- 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 SymptomsSmall, painful, fluid-filled blisters around the lips or edge of the mouthTingling or burning around the mouth or nose, often a few days before blisters appearFeverSore throatSwollen lymph nodes in neck

Herpetic whitlow 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.

Hand ,foot and mouth syndrome

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 throatFeeling of being unwell (malaise)Painful, red, blister-like lesions on the tongue, gums and inside of the cheeksA red rash, without itching but sometimes with blistering, on the palms, soles and sometimes the buttocksIrritability in infants and toddlersLoss 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.

IMPETIGOContagious bacterial infection of epidermisCan affect any skin regionTransmitted by direct contact with infected persons or fomitesPrimary impetigo: more common in children, infection via minor breaks in skinSecondary impetigo: any age, secondary infection of trauma/woundsClinical 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

Maculopapular rashes

Causes of Maculopapular RashRubeola (Measles)Rubella (German Measles)Roseola (Exanthema Subitum)Chikungunya Virus (Dengue)Parvovirus B19 (Erythema Infectiosum or Fifth Disease)Infectious Mononucleosis

Kawasaki diseaseDrug EruptionsOthers (Cytomegalovirus (CMV), Salmonella typhi (Typhoid Fever), Enteroviruses,etc.)

MeaslesThe 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) 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

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

RUBELLA- 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: 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

ROSEOLA INFANTUMThe 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 INFECTIOUSMErythema infectiosum is caused by infection with PV-B19, a member of the Parvoviridae family. Signs and symptomsMild 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

SCARLET FEVER

CauseErythrogenic toxin-producing strain of Group A beta-haemolytic Streptococcus

FeaturesIncubation 2-4 daysBright 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)

TreatmentSymptomatic relief Penicillin V 7-10 days

KWASAKI DISEASE 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 feetpeeling skin around the fingertips, hands or feet (occurs later in the illness)

2-non-specific rash on the body, often accentuated in the groin area3-bloodshot eyes (no discharge)4-redness in the lips, mouth and tongue

dry, red, cracked lipsinflamed, red mouthswollen, 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 irritabilitydiarrheavomitingabdominal painenlarged liver or gallbladdercough 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 lower-dose aspirin for its antiplatelet effects.

Aspirin is used in patients with small coronary artery aneurysms (CAAs).

Dipyridamole is indicated in patients with larger CAAs.

PETICHAL &PURPURIC RASH

DescriptionPurpura : 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

Causes of purpuric & peticheal rash

non-thrombocytopenic purpura : Congenital causes such as:

Hereditary haemorrhagic telangiectasia  Connective tissue diseases such as Ehlers-Danlos

syndrome  Congenital cytomegalovirus (CMV) and 

congenital rubella. 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 - post-transfusion purpura).

Coagulation problems (eg  (DIC), thrombocytopenic purpura,).

Sequestration of the platelets as occurs in splenomegaly.

MENINGEOCOCCEMIAMeningococcemia 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 meningitisSymptomsThere may be few symptoms at first. Some may include:FeverHeadacheIrritabilityMuscle painNauseaRash 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-Schonlein PurpuraHenoch-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 symptomsThe typical prodrome of HSP includes the following(Headache ,Anorexia,FeverSubsequently, 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

Other common skin disorders in pediatrics

Contact Dermatitis 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

Diaper dermatitis (diaper rash)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).

SEBORRHAIC DERMATITIS(Cradle Cap)

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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