Fractional Exhaled Nitric Oxide and Impulse Oscillometry in Children With Allergic Rhinitis

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	Allergy Asthma Immunol Res. 2013 Aug;5:e191. English. Published online 2013 August 22.  Copyright © 2013 The Korean Academy of Asthma, Allergy and Clinical Immunology • The Korean Academy of Pediatric Allergy and Respiratory Disease Yoon Hee Kim, Hyun Bin Park, Min Jung Kim, Hwan Soo Kim, Hee Seon Lee, Yoon Ki Han, Kyung Won Kim,Myung Hyun Sohn and Kyu-Earn Kim Department of Pediatrics and Institute of Allergy, Severance Biomedical Science Institute, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea. Correspondence to: Kyung Won Kim, MD, PhD, Department of Pediatrics, Institute of Allergy, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea. Tel: +82-2-2228-2050; Fax: +82-2-393-9118, Email: kwkim@yuhs.ac  Received September 26, 2012; Revised March 21, 2013; Accepted April 03, 2013. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract Purpose Airway inflammation, bronchial hyper-responsiveness (BHR), and bronchodilator response (BDR) are representative characteristics of asthma. Because allergic rhinitis (AR) is a risk factor for asthma development, we evaluated these 3 characteristics in AR using measurement of fractional exhaled nitric oxide (FeNO), a methacholine challenge test (MCT), and impulse oscillometry (IOS). Methods This study included 112 children with asthma (asthma group), 196 children with AR (AR group), and 32 control subjects (control group). We compared pulmonary function parameters and FeNO levels among the 3 groups. The AR group was subdivided into 2 categories: the AR group with BHR and the AR group without, and again pulmonary function and FeNO levels were compared between the 2 subgroups. Results FeNO levels were more increased in the AR and asthma groups than in the control group; within the AR group, FeNO was higher in the AR group with BHR than in the AR group without. The BDR was more increased in the AR group than in the control group when percent changes in reactance at 5 Hz (Δ X5) and reactance area (Δ AX) were compared. In the AR group, however, there was no difference in Δ X5 and Δ AX between the AR group with BHR and the AR group without. Conclusions Reversible airway obstruction on IOS and elevated FeNO levels were observed in children with AR. Because elevated FeNO levels can indicate airway inflammation and because chronic inflammation may lead to BHR, FeNO levels may be associated with BHR in AR. IOS can be a useful tool for detecting lower airway involvement of AR independent of BHR assessed in the MCT. Keywords: Asthma, allergic rhinitis, bronchial hyper-responsiveness, bronchodilator effect, child, nitric oxide. Formats: Abstract Article PubReader PDF Figures + Tables References