The nature of allergic rhinitis (AR) in preschool children has yet to be clearly characterized. The aim of this study was to investigate the prevalence and its risk factors of AR and its relationship with FeNO in preschool children.
This is a population-based, cross-sectional survey of 1757 preschool children, aged 3-7 years in Korea in 2010. A modified International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was used. In addition, skin prick tests (SPT), serum total IgE and specific IgE were assessed. Current AR was defined as having nasal symptoms within the last 12 months and diagnosed AR by clinicians. Atopy was defined who had one or more positive reactions on SPT.
The prevalence of current AR in preschool age was 23.0% (392 out of 1702) and atopic current AR was 9.65% (93 out of 964). Parental AR (aOR, 3.60; 95% CI, 1.74-7.47), past history of asthma diagnosis (aOR, 2.09; 95% CI, 1.39-3.16) and past history of atopic dermatitis diagnosis (aOR, 1.46; 95% CI, 1.13-1.89) were the independent risk factors for current AR. Specifically, mold exposure during infancy (aOR 1.46; 95% CI, 1.13-1.88) and use of antibiotics in infancy (aOR, 1.89; 95% CI, 1.46-2.45) were also associated with an increased risk of current AR, whereas having older sibling (aOR, 0.53; 95% CI, 0.41-0.69) reduced the risk. Furthermore, atopic current AR without asthma diagnosis had significantly higher geometric mean FeNO levels compared with non-atopic current AR (12.47; 95% CI, 9.85-15.78 vs. 8.72; 95% CI, 8.31-9.15, P=0.0007) as well as higher compared with non-atopic healthy children (8.55; 95% CI, 7.97-9.17, P=0.0004). IgE level (232.9; 95% CI, 179.4-302.4 vs. 68.43; 95% CI, 62.51-74.91, P=<.0001) and eosinophil fraction (4.65; 95% CI, 3.96-5.46 vs. 2.86; 95% CI, 2.72-3.01, P=<.0001) of atopic current AR were higher than non- atopic current AR group.
AR is a common disease in Korean preschool children. Mold exposure and antibiotics use during infancy increased the risk whereas older sibling decreased the risk of AR. Furthermore, FeNO levels, IgE, and eosinophil were higher in atopic current AR without asthma group, which suggests FeNO can be a useful diagnostic tool of AR in preschool children.
This study was supported by grant of the Korean Health Technology R&D Project, Ministry of Health & Welfare, Republic of Korea (A092076 and HI13C1674).