FEF25–75 Might Be a Predictive Factor for Bronchial Inflammation and Bronchial Hyperreactivity in Adolescents with Allergic Rhinitis

Abstract

Allergic rhinitis and asthma are closely associated. Bronchial hyperreactivity (BHR) is a pathophysiological characteristic of asthma. Allergic inflammation is characterized by eosinophilic infiltrate and may by indirectly assessed by exhaled nitric oxide (FeNO). Forced expiratory flow between 25 percent and 75 percent of vital capacity (FEF25-75) may predict BHR in adult patients with allergic rhinitis. The aim of this study was to evaluate the presence of BHR in a large group of adolescents with allergic rhinitis and whether FEF25-75 might be related with BHR and FeNO. Methods 150 adolescents with allergic rhinitis were enrolled. Clinical examination, skin prick test, spirometry, methacholine challenge, and FeNO were performed in all patients. Results Severe BHR is quite frequent in allergic adolescents. Impaired FEF25-75 values (such as less than 65 percent of predicted) constitute a relevant predictive factor for severe BHR (OR 4.4). FeNO levels were significantly related with BHR. Conclusion This study provides evidence that impaired FEF25-75 values might predict severe BHR and BHR is related with FeNO in adolescents. Therefore, BHR should be suspected in adolescents with low FEF25-75 values.