Atopic dermatitis and allergy

Abstract

Though the etiopathogenesis of atopic dermatitis is still unknown, there are several known mechanisms involved: immunological, psychological, metabolic, genetic and others. It seems likely that there are 2 groups of atopic dermatitis: allergic and nonallergic. In the first group, IgE is probably formed locally and plays an important role in immunologic pathogenesis. Gerrard (1973) thinks that cow's milk is important. If cow's milk is given at an early age, when the gastrointestinal tract is relatively defenceless, the infant becomes sensitized. Gerrard recommends that babies with a definite hereditary background of allergy be fed on breast milk only. According to Hjort and Wilkinson (1973), when fixation of IgE on target cells occurs, the lymphocytes release an eczema producing factor causing spongiosis. However, a certain minimal hereditary predisposition, plus intensive allergen exposure (sensitization), plus tissue conditioning factors (infections, toxic, metabolic, biochemical and microcirculatory changes) are necessary to produce this. In the other group, nonallergic dermatitis, several nonimmunological factors are involved. In the allergic group with strongly positive skin tests (10 mm), one can try very low doses of extracts for hyposensitization, often with good results. Local treatment is important and depends on the condition of the skin. Dietary control and improvement of environment consititutes other elements in the treatment of this common dermatitis.