The role of inhaled and/or nasal corticosteroids on the bronchodilator response

Results: The mean BDR was 10.3% [95% confidence interval (CI) 8.312.4%] in children with asthma, 9.0% (95% CI 7.3-10.9%) in subjects with asthma and AR, and 5.0% (95% CI 4.1-5.9%) in children with AR alone (P<0.001). After treatment, the mean BDR was reduced to 5.2% (95% CI 4.2-6.3%) (P<0.001) in children with asthma and to 4.5% (95% CI 3.5-5.5%) (P<0.001) in children with asthma and AR. However, children with rhinitis showed no significant change in BDR after treatment, with the mean value being 4.7% (95% CI 3.7-5.8%) (P=0.597). Conclusion: The findings of this study imply that an elevated BDR in children with AR cannot be attributed to nasal inflammation alone and highlights the close relationship between the upper and lower airways.