To assess the independent and joint effects of parental atopy and exposure to molds on the development of asthma in childhood, the authors conducted a cohort-based, incident case–control study in 2008. The case group consisted of 188 children with new asthma, and the control group (n = 376) was matched one to two for age and sex. The outcome of interest was the development of asthma during the study period. The studied determinants were parental atopy and three indicators of exposure including histories of water damage, presence of visible molds, and perceived mold odor in the home at baseline in 2002. In conditional logistic regression adjusting for confounding, parental atopy [adjusted odds ratio (aOR) 3.29, 95% CI 2.19–4.94] and the presence of mold odor (aOR 2.09, 95% CI 1.30–3.37) and visible mold (aOR 1.76, 95% CI 1.18–2.62) were independent determinants of incident asthma, and apparent interaction in additive scale was observed. Our finding suggests that the interaction between parental atopy and molds may play a role in the development of asthma in children.Practical Implications
Our study strengthens the evidence for the roles of indoor dampness problem and parental atopy as determinants of asthma in children. Furthermore, the interaction between parental atopy and exposure to molds suggests a role for the development of childhood asthma, i.e., the children whose parents had atopic disease and molds exposure are more susceptible to develop asthma.