Exposure to moldy or damp indoor environments is associated with allergic disease in young children, but it is unclear whether the effects persist to adolescence. Our objective was to assess whether exposure to mold or dampness during infancy increases the risk of asthma, rhinitis, or IgE sensitization in children followed from birth to 16 years of age.

We collected questionnaire derived reports of mold or dampness indicators and allergic outcomes from 3798 children in a Swedish birth cohort (BAMSE). Sensitization was assessed from blood samples in 3293 children. Longitudinal associations between prevalent asthma, rhinitis, and IgE sensitization and mold or dampness indicators were assessed using generalized estimating equations.

Exposure to any mold or dampness indicator was associated with asthma up to 16 years of age (OR 1.31; 95% CI 1.08–1.59), while exposure to mold odor (OR 1.29; 95% CI 1.03–1.62) and visible mold (OR 1.28; 95% CI 1.04–1.58) were associated with rhinitis. Increased risks were observed for nonallergic asthma (OR 1.80; 95% CI 1.27–2.55) and rhinitis (OR 1.41; 95% CI 1.03–1.93). No association was observed between mold or dampness indicators and IgE sensitization. Exposure to any mold or dampness indicator was associated with persistent asthma (OR 1.73; 95% CI 1.20–2.50), but not with early‐transient or late‐onset asthma.

Exposure to mold or dampness during infancy increased the risk of asthma and rhinitis up to 16 years of age, particularly for nonallergic disease. Early exposure to mold or dampness appeared particularly associated with persistent asthma through adolescence.