Petkeeping and exposure to mite and cat allergens in children from East and West Germany

One possible explanation for the differences in the prevalence of atopic se nsitization between children from East and West Germany could be difference s in the exposure to indoor allergens. This study examined whether pets wer e kept less frequently in households of children (5 - 7 and 9 - 11 years ol d) in Dresden than in Munich and whether there were differences in indoor c oncentrations of mite and cat allergens. We analysed questionnaire data fro m 6317 German children in Dresden and 4777 children in Munich and investiga ted allergen levels in 296 homes in Dresden and 297 homes in Munich. Cats a nd dogs were kept less frequently in Dresden than in Munich before 1990 as well as after 1990. In contrast, only small differences were found for smal ler pets. Guinea pigs were kept more frequently in Dresden before and after 1990. Petkeeping increased between 1986 and 1996 in both cities. This tren d was more pronounced in Dresden. The sum of house dust mite group 1 allerg ens (Derp 1 + Der f 1) did not differ significantly in Dresden [geometric m ean (GM) 2, 19, 95% confidence interval (CI) 1,54-3,10 mu g/g dust] and Mun ich (GM 2,46, 95% CI 1,78-3,39 mu g/g dust). In contrast, a lower concentra tion of the cat allergen Fel d 1 was found in Dresden (GM 26, 95% CI 19-36 ng/g dust) compared to Munich (GM 118, 95% CI 85-164 ng/g dust, p < 0,0001, Mann-Whitney U-test). Considering the results of other investigators these data suggest that cat allergen exposure was lower in East German than in W est German homes whereas mite allergen concentrations vary substantially wi thin both regions and do not differ consistently between East and West Germ any.