Environmental risk factors for respiratory and skin atopy: results from epidemiological studies in former East and West Germany.

The fall of the Berlin wall in 1989 offered the unique opportunity to compare populations of a similar genetic and geographic background which had been living under quite different environmental exposure conditions for over 40 years. Since 1990 comparative epidemiological studies were performed between various regions in former East and West Germany with yearly questionnaires and 3 years' physical, dermatological, allergological and exposure examination in a total of about 30,000 preschool children. There were striking differences between the various German regions with higher prevalence rates of respiratory atopy (hay fever, asthma) and atopic sensitization (prick test, RAST) in West Germany, while atopic eczema was significantly higher in East Germany (17.5 vs. 11.4% in West Germany). Total serum IgE levels were markedly higher in children in the east of Germany, similarly to the prevalence of parasitic infestation (questionnaire data as well as positive ascaris RAST). In multivariate logistic regression analysis the following factors were significantly associated with atopic eczema: animal contact (odds ratio, OR 2.9), animal furs in the bedroom (OR 2.2), use of gas without ventilation (OR 1.7) and living near road with heavy traffic (OR 1.7). Furthermore, socioeconomic factors measured as parental educational status (university vs. elementary school) were significantly associated (OR 2.3) with atopy. Respiratory tract infections and irritant responses decreased together with decreasing SO2 and suspended particulate air pollution in East Germany from 1991 to 1997. It is concluded that environmental factors from the physical, chemical, biological, and psychological environment (characteristic of a 'modern' or 'western' society) do influence the development of atopic sensitization and disease.