Peak expiratory flow monitoring to screen for asthma in patients with allergic rhinitis.

AIM To investigate the benefit of using peak expiratory flow (PEF) monitoring to screen for asthma in allergic rhinitis patients. METHODS Eighty-nine consecutive patients with allergic rhinitis but never assessed for asthma were included in this prospective study. Their allergic status was determined by skin prick tests. All of the subjects filled in a questionnaire on asthma-like symptoms. If they reported such symptoms, pulmonary function tests were carried out. Then, PEF was checked twice daily for 3 weeks. RESULTS Thirty-six percent of our study group were male and 64% were female patients with a mean (SD) age of 36.3 (14.0) years. Skin prick tests were positive to grass mixture in 71 (79.8%) patients, to tree mixture in 51 (57.3%), to mite in 46 (51.7%), and to epidermal mix in 26 (29.2%) patients. Thirty-six patients (41%) reported 3 or more asthma symptoms. Lung function test results for these 36 patients showed obstruction for 11.1% (4 patients); the remaining patients (88.9%) had normal function parameters. The subjects who reported 3 or more asthma symptoms but had normal lung function monitored their PEF for 3 weeks. Sixteen (50%) patients from this group and the 4 patients with demonstrated airway obstruction had more than 20% diurnal variation in PEF. These 20 patients' asthma symptoms disappeared after they received 3 months of low-dose inhaled corticosteroid therapy. CONCLUSION It is necessary to look for asthma in patients suffering from allergic rhinitis. PEF monitoring is a low-cost, objective approach to asthma diagnosis that can be performed by a patient with allergic rhinitis even if spirometry is normal. Knowledge of this technique is of utmost importance because delay in diagnosis will result in the unsatisfactory treatment of the disease.