Atopisches Ekzem - Die Bedeutung der Hautbarrierefunktion fur Pathogenese und Therapie

Altered epidermal barrier function of varying degrees as determined by transepidermal water loss (TEWL) is a typical feature in patients with atopic eczema (AE) in both eczematous skin lesions and in clinically normal dry skin. It is hypothesized that the stratum corneum lipids in these patients show quantitative and/or qualitative changes. Measurements of the TEWL of positive atopy patch test (APT)-reactions to aeroallergens and of positive patch test reactions to classical contact allergens in the same AE patients showed that the epidermal barrier function is altered only in the positive APT-reactions. The immune reaction characteristic of AE would be a possible explanation for this altered epidermal barrier function. As a consequence of the altered epidermal barrier function comparatively large aeroallergens can more easily penetrate the skin and bind on specific IgE-receptors, thus forming a vicious circle and perpetuating the atopic status. Well-known dermatological topical therapy such as lotio alba enhances epidermal barrier regeneration, so that this treatment of acute forms of AE can now be substantiated pathophysiologically.