Modifiable Factors Impacting Risk of Allergic Rhinitis in Young Children: A Prospective Cohort Study

Background This study is aimed at identifying early‐life modifiable factors associated with allergic rhinitis to assist in reducing the public health burden of allergic rhinitis on young children and their families. Methods Children of mothers with asthma in the Breathing for Life Trial cohort were followed over 4 years. Potential risk and preventative exposures (outdoor, home environment and early life) were measured at 12 months using a validated parent‐reported questionnaire. Validated questionnaires and a skin prick test were administered to collect outcome data at 4 years—allergic rhinitis symptoms ( n = 285), hay fever ( n = 276), airborne allergen sensitisation ( n = 142) and persistent rhinitis ( n = 285). Multivariate logistic regression assessed associations, and population attributable fractions (PAFs) and prevented fractions for the population (PFPs) were calculated. Results Parent‐reported bronchiolitis before 12 months of age was associated with allergic rhinitis symptoms (adjOR 1.95, 95% CI 1.07–3.57, PAF 17.6%). Additionally, hospitalised bronchiolitis was associated with hay fever (PAF 13.5%). Cat ownership was associated with lower odds for allergic rhinitis symptoms and persistent allergic rhinitis (PFP 17% and 24.2%, respectively), and dog ownership was associated with lower odds for hay fever (PFP 23.7%). Additionally, gas cooking was associated with reduced persistent allergic rhinitis (PFP 22.5%) and total breastfeeding for 4–6 months with reduced hay fever (PFP 14.9%). Associations with traffic frequency, second‐hand smoking, type of heating and childcare attendance were not significant. Conclusion Early respiratory infection and cat and dog exposure were identified as potentially modifiable exposures to reduce the risk of childhood allergic rhinitis.