Epidemiologie des atopischen ekzems

Atopic eczema is the most common chronic inflammatory skin disease in childhood. According to the ISAAC study, prevalence in childhood ranges between 1% and 16%. German studies show a prevalence for children of over 10% and for adults of about 3%. Numerous studies over the past decades confirmed a significant increase in prevalence also in Germany. In East and West Germany, within the period of 1991-2000, over 33,300 pre-school children were interviewed, and about 4,500 were clinically examined. The lifetime prevalence (15.5% vs. 12.7%; odds ratio [OR] 1.92, confidence interval [CI] 1.09-1.31) and prevalence on the date of examination (11.5% vs. 8.1%, OR 1.64, CI 1.34-2.02) were significantly higher in East Germany. Lifetime prevalence has increased significantly in both regional parts of the country. The intrinsic type (no reaction to the skin prick test) was more common in East Germany (8.5% vs. 4.7%, OR 1.77, CI 1.12-2.79). The preventive effect of breastfeeding was confirmed by a large population-based study from Belarus, where enhanced breastfeeding led to halving of the eczema prevalence after one year (3.3% vs. 6.3%, OR 0.54, CI 0.31-0.95). According to preliminary results of the GINI study, only strongly hydrolyzed caseine-based formulas are able to reduce eczema prevalence in genetically predisposed children. The use of probiotics seems to be helpful in terms of prevention and therapy. Data concerning the influence of infections and vaccinations in childhood for the manifestation of eczema are still to be regarded as ambiguous. Living on a farm and exposure to endotoxins seem to have hardly any effect on the development of atopic eczema. While some studies regard keeping small pets as risk factor, others showed a preventive effect by keeping larger animals; a possible selective use of preventive measures, especially by genetically predisposed groups, should be regarded thoroughly when interpreting these results. The results of epidemiologic studies may contribute to the pathogenetic understanding and thus to the development of preventive measures.