Photo Credit: By-studio

Season of birth (SOB) is associated with asthma and allergic rhinitis, according to a letter to the editor published online in Clinical and Translational Allergy. Researchers examined the potential association of SOB with airway allergy and related diseases in Finland using a randomly sampled retrospective registry-based follow-up study of 74,868 patients (mean age, 34.53 years). The population was divided into four groups based on SOB. The researchers found that the proportion with asthma was 43.1%, 42.1%, 41.1%, and 42.7% for the winter, spring, summer, and autumn SOB groups, respectively. The corresponding proportions with allergic rhinitis were 12.6%, 12.0%, 10.7%, and 12.1%. Compared with summer SOB, being born in any other season was significantly associated with allergic rhinitis, and being born in autumn or winter was associated with asthma. In adjusted models, no significant association was seen for chronic rhinosinusitis, nonsteroidal anti-inflammatory drug-exacerbated respiratory disease, or nonallergic rhinitis.