Prevalence of atopy and asthma in eastern versus western Europe: why the difference?

Learning Objectives: This article reinforces the reader's knowledge of the epidemiology of allergy and asthma in eastern versus western European countries and the ability to recognize the different hypotheses formulated to explain the rising trend of allergic asthma in Europe. Data Sources: Articles in English comparing the epidemiology of allergy in eastern versus western Europe published before December 31, 2000. Results: Significant higher prevalences of atopy and allergic asthma were observed in the early 1990s among populations living in western compared with eastern European countries. Changes in lifestyle after the fall of the communist system were associated with an increasing trend of atopic sensitization and hay fever in former East Germany after only 6 to 8 years after the Germany reunification. It has been hypothesized that a similar "converging" trend in the prevalence of allergic asthma and of bronchial hyperresponsiveness may take longer periods. Conclusions: The prevalence of allergic asthma has increased decades earlier in western Europe with respect to eastern Europe. This is probably attributable to changes in lifestyle that had already occurred rather than to air pollution. The factory of a western lifestyle (diet, hygiene, varied allergen exposure) that have determined the difference in allergic asthma prevalence across Europe have yet to be identified.