The home environment and current dermatitis in Japanese junior high school children in Kansai area

There is little information on indoor risk factors for dermatitis in Japan. We studied associations between dermatitis in Japanese junior high school students in Hyogo prefecture and the home environment. A standardised questionnaire was sent to students in four schools (12-15 years old), 1048 (99%) participated. Data on the home environment was collected by the questionnaire. Associations were analysed by multilevel logistic regression in mutually adjusted models, calculating odds ratio (OR) with 95% confidence intervals. A total of 15.2% reported current dermatitis, 8.8% cat allergy, 6.1% dog allergy, 6.0% mould allergy, 25.7% pollen allergy and 32.3% any allergy (a history of atopy). Female gender (OR 1.65), a history of atopy (OR 2.14), new building materials (indoor paint or floor materials) (OR 1.59), dampness or indoor mould (OR 1.51) and windowpane condensation in winter (OR 1.45) were associated with current dermatitis. The association between window pane condensation and dermatitis was stronger in students without a history of atopy (interaction p=0.02). In conclusion, dampness, indoor mould and window pane condensation in wintertime can be household risk factors for dermatitis in adolescents. Chemical emissions from new building materials, especially paint and floor materials, can be another risk factor.