PREVALENCE OF AND RISK-FACTORS FOR ALLERGIC DISEASES - COMPARISON OF 2 CITIES IN JAPAN

Background: Differences in the prevalence of allergic diseases and the effects of genetic and environmental factors on these diseases in two areas of the same country have not been examined by multiple logistic regression. Objective: To determine whether the effects of genetic an d environmental factors on allergic diseases differ between two areas. Methods: A questionnaire was distributed in March 1991 to children le ss than 16 years old attending kindergarten, elementary, or junior hig h school in two Japanese cities; Gifu, with a temperate climate, and I toman, with a subtropical one. The number of subjects analyzed were 12 43 in Gifu and 1953 in Itoman. Multiple logistic regression analysis w as performed using SAS. Results: The prevalences of allergic diseases and atopic dermatitis in Gifu were significantly higher than in Itoman (P <.05). In contrast, the prevalence of bronchial asthma in Itoman w as significantly higher than in Gifu (P <.05). Multiple logistic regre ssion analysis showed that in both cities children of families with al lergic histories have significantly higher risk of contracting an alle rgic disease and atopic dermatitis. The prevalences of allergic diseas es and atopic dermatitis were higher in Gifu than in Itoman, even afte r being controlled for genetic and environmental factors. Conclusions: The increased risk of contracting an allergic disease and atopic derm atitis for the children in Gifu may be due to such factors not include d in the study as climate, eating habits, or the level of air pollutio n.