Methods: This is a general population-based, cross-sectional survey of 1757 preschool children in Korea. Those with physician-diagnosed asthma were excluded. A modified International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was used. Current AR was defined as having nasal symptoms within the last 12 months and physician-diagnosed AR.
Results: Children with atopic current AR had significantly higher geometric mean levels of FeNO compared with those in non-atopic current AR (12.43; 95% CI, 7.31-21.13 vs. 8.25; 95% CI, 5.62-12.10, P=0.008) as well as non-atopic healthy children (8.58; 95% CI, 5.51-13.38, P=0.013). FeNO levels were higher in children with atopic current AR compared with those of atopic healthy (12.43; 95% CI, 7.31-21.13 vs. 9.78; 95% CI, 5.97-16.02, P=0.121). Total serum IgE levels and eosinophil percentage were significantly higher in children with atopic current AR compared with those with non-atopic current AR.
Conclusions: FeNO level was higher in preschool children having atopic current AR, which suggests that FeNO level can be a useful diagnostic biomarker in these children.