Almqvist C, et al. - This investigation examined the relationship between season of birth and risk of childhood asthma/wheeze or allergic rhinoconjunctivitis in a population-based setting and the mediating impact of lower respiratory infections. From the nationwide Swedish Medical Birth, Patient and Prescribed Drug Registers, two population-based cohorts have been identified. The authors found that the birth season association with childhood asthma/wheeze risk, but not allergic rhinoconjunctivitis, is partly mediated by lower respiratory infections. The connection was comparable for allergic rhinoconjunctivitis in the 7^th year of life, but not mediated by respiratory infections.