Bronchial hyperreactivity in patients with allergic rhinitis: forced expiratory flow between 25 and 75% of vital...

Allergic rhinitis (AR) is considered a strong risk factor for the onset of asthma. Bronchial hyperreactivity (BHR) may be present in patients with AR. Forced expiratory flow between 25 and 75% of vital capacity (FEF(25-75)) may be impaired in AR patients. The aim of this study was to evaluate the presence of BHR in a large group of patients with AR and whether FEF(25-75) might be related to BHR. Four thousand seven hundred eighty-one patients with AR were enrolled. Clinical examination, skin-prick test, spirometry, and methacholine challenge were performed in all patients. Fourteen percent of patients had severe BHR and 25.3% had mild BHR. Patients with low FEF(25-75) values (such as ≤65% of predicted) had severe BHR more frequently than patients with normal FEF(25-75) values (p < 0.001). In addition, low FEF(25-75) values constitute a relevant predictive factor (OR = 12.9) for severe BHR. This study shows that a relevant percentage of AR patients had BHR, and impaired FEF(25-75) values might predict it. Therefore, BHR should be suspected in AR patients with low FEF(25-75) values.