Environmental risk factors for allergic rhinitis differ by income level: A Global Asthma Network survey

BACKGROUND: Estimating the prevalence and identifying risk factors for allergic rhinitis (AR) provides critical burden of disease data and offers opportunity to intervene in early-life preventing morbidity. METHODS: We conducted a Global Asthma Network (GAN) Phase I cross-sectional study in children (6-7 years) and adolescents (13-14 years). Multilevel logistic regression models were fitted with random intercepts for school, center, and country, adjusting for sex and country income at the child level. Associations between symptoms and a range of lifestyle and environmental risk factors were assessed using odds ratios and corresponding 95% confidence intervals for mean individual and school exposure. Participants provided informed consent/assent, and each center was required to provide proof of ethical clearance. RESULTS: We analysed data from 266,182 children and adolescents across 1688 schools in 65 centers for AR symptoms. Prevalence was 8.5% in children and 13.3% in adolescents. Early-life exposures strongly associated with AR included paracetamol use (OR: 2.03; 95% CI: 1.89-2.18) and antibiotics (OR: 1.67; 95% CI: 1.56-1.78), with a stronger effect for antibiotics in low- and middle-income countries (LMICs). Farm animal exposure increased AR risk among LMIC children (OR: 1.31; 95% CI: 1.12-1.53). In adolescents, computer use (OR: 1.28; 95% CI: 1.22-1.35) and tobacco use (OR: 1.37; 95% CI: 1.29-1.46) were significant risk factors. Heavy truck traffic consistently elevated AR risk in both age groups. CONCLUSION: The prevalence of AR is stable; early-life exposures to animals increased the risk for AR in children from LMICs. Lifestyle factors and poor air quality from traffic-related pollutants increase the risk of AR.