Skin Allergy in Childern
Urticaria :
Urticaria is an allergic disorder characterized by its lesions : "wheels" . These are erthematous raised, circumscribed skin lesions which are intensely pruritic . They result from capillary dilatation and increased capillary permeability leading to edema in the upper corium of the skin . Immunologic and non-immunologic mechanism are resposible for the pathogenesis of urticaria .
The allergens may be ingestants (food, drugs), contactants (insects, plants), injectants (drugs, insect bites, antisera), inhalants (pollens) or physical factors (cold, heat) . Urticaria is usually self-limited .
Antihistamines like diphenhydramine or loratadine can be used . In severe extensive cases, epinephrine 1/1000, 0.01 ml/kg subcutaneously may be of help . Corticosteroids may be used in chronic cases .
Urticaria :
Urticaria is an allergic disorder characterized by its lesions : "wheels" . These are erthematous raised, circumscribed skin lesions which are intensely pruritic . They result from capillary dilatation and increased capillary permeability leading to edema in the upper corium of the skin . Immunologic and non-immunologic mechanism are resposible for the pathogenesis of urticaria .
The allergens may be ingestants (food, drugs), contactants (insects, plants), injectants (drugs, insect bites, antisera), inhalants (pollens) or physical factors (cold, heat) . Urticaria is usually self-limited .
Antihistamines like diphenhydramine or loratadine can be used . In severe extensive cases, epinephrine 1/1000, 0.01 ml/kg subcutaneously may be of help . Corticosteroids may be used in chronic cases .
Papular urticaria :
Usually occurs in childern (<10 years), in summer time, following insect bites (fleas, mosquitoes, animal lice, bed bugs) . A bit may incite an "ad" reaction at distant sites . These are small papules which itch markedly and soon become excoriated . Vesiculation is commen . Lesions tend to occur on the exposted parts of the body (arms, legs, necks, face) . Palms and soles are the commonest sites .
Treatment :
- Local calamine lotion (with 0.25% menthol & 0.5% phenol), cool compresses.
- Oral antihistamines (to relieve pruritis) or a short course of systemic steroids.
- Topical corticosteroids and antihistamines are rarely effective.
- Insect repellents containing diethyltoluamide (DEET) for mosquitoes and fleas.
- Control of insects.
Infantile Eczema (Atopic dermatitis) :
It is an inflammatory skin disorder characterized by erythema, edema, intense pruritus, exudation, crusting and scaling.
Suggested Etiology : Allergy or skin hyperreactivity.
Clinical picture :
● Onset is usually in infancy (with introduction of foreign foods in the diet). There are erythematous, markedly pruritic, weepy patches mainly on the cheeks and extensor surfaces.
● A remission occurs at about 3-5 years of age when the disease becomes quiescent. Mild eczema may persist in the cubital and popliteal fossae or behind the ears.
● Drying and thickening of the skin occur with increasing age.
● The face takes a whitish hue (mask of atopic dermatitis). Hyperpigmentation, scaling and lichenification occur.
● A lasting remission usually occurs in the 4th decade of life.
Complications : Secondary infection, keratoconus from the continuous rubbing of the eye, and cataract.
Differenial diagnosis : Other causes of dermatitis as seborrheic dermatitis, contact dermatitis, acrodermatitis,.....
Treatment : includes control of the "itch-scratch-itch" cycle :
● Avoidance of ingestants, contactants (as wool and detergents), injectants and atmospheric factors that can trigger itching and scratching (e.g. extremes of temperature and humidity).
● Warm moderately humid climate, oil baths and creams to seal water into skin, cotton garments.
● Topical corticosteroids and antihistamines.
● Systemic steroids are used only in severe cases.
