Swimming was associated with rhinitis and pollinosis in a duration‐dependent manner

Abstract Background Previous studies have reported conflicting results regarding the effects of childhood swimming on respiratory allergic symptoms. We investigated the relationship between swimming and respiratory allergic symptoms in schoolchildren. Methods A questionnaire regarding participation in sports club activities and respiratory allergic symptoms in schoolchildren was distributed to the parents of all 6853 public school students (aged 6–14 years) in Omihachiman City, Shiga, Japan. The relationships between participation in sports club activities and the prevalence of respiratory allergic symptoms were analyzed by multivariable logistic regression analyses. Results Questionnaires were returned for 4991 schoolchildren (response rate: 72.8%). Logistic regression analysis revealed significant positive associations between swimming and rhinitis (42.9% vs. 38.9%; adjusted odds ratio, 1.26; 95% confidence interval, 1.10–1.44), and swimming and pollinosis (32.1% vs. 28.1%; adjusted odds ratio, 1.28; 95% confidence interval, 1.11–1.47). The duration of participation in swimming activities was also significantly positively associated with the prevalence of rhinitis and pollinosis. Those who had participated in swimming activities for 6 years or more showed significantly higher prevalences of rhinitis and pollinosis (46.3% and 36.4%, respectively) than those without swimming activities (38.9% and 28.1%, respectively) and those who had participated in swimming activities for 5 years or less (40.1% and 28.5%, respectively). Conclusions Swimming was associated with the prevalence of rhinitis and pollinosis in schoolchildren, especially among those who had participated in swimming activities for 6 years or more. Preventive measures and early interventions for rhinitis and pollinosis should be recommended to these children.