Indoor allergens, asthma, and asthma-related symptoms among adolescents in Wuhan, China

Purpose Information on indoor allergen exposures among non-Western populations, which have lower prevalence of atopic illness, is scant. We examined whether exposures to common indoor allergens were associated with doctor-diagnosed asthma and asthma-related symptoms among Chinese adolescents. Methods A cross-sectional study of 4185 ninth grade students was conducted at 22 randomly selected schools in Wuhan, China. Information on respiratory health and exposures to indoor allergens was obtained by a self-administered questionnaire completed in class. Results Having animals currently was associated with persistent cough [prevalence odds ratio (POR) = 1.54, 95% confidence interval (CI ): 1.21–2.11] and wheeze (POR = 1.41, 95% CI: 1.03–1.94). Early-life exposure to animals was also associated with doctor-diagnosed asthma (POR = 1.95, 95% CI: 1.35–2.82). Associations with respiratory symptoms strengthened with higher levels of exposure and for exposure in both early childhood and in adolescence. Exposure to cockroaches and having mold/water damage in the home contributed especially to wheezing (POR = 2.03, 95% CI: 1.41–2.90 for cockroaches; POR = 2.49, 95% CI: 1.82–3.40 for mold/water damage). Conclusions Indoor allergen exposures were positively associated with asthma diagnosis and persistent respiratory symptoms among Chinese adolescents. Neither early-life nor current exposure to animals was protective for asthma or asthma-related symptoms.