Clinical differentiation between resistant asthma and chronic bronchiolitis: testing a practical approach.

Intractable asthma is a challenging clinical problem. This study was conducted to determine whether a subset of patients with Intractable asthma may be misdiagnosed and have a form of bronchiolitis instead and also to determine the effectiveness of macrolide therapy in these patients. Seventy six patients with Intractable asthma were re-treated with recommended maximal doses of oral prednisolone for 5 days, beclomethasone, cromolyn sodium, salbutamol and ipratropium bromide for 30 days. Thirty five patients were considered as unresponsive and constituted the study group. They underwent high-resolution CT (HRCT) scan following which they were offered with video-assisted thoracoscopic surgical biopsy. Group 1 (n= 27) refused biopsy and each was treated with macrolide therapy, while Group 2 (n=8) underwent biopsy, and then received macrolide therapy. The patients were treated and followed for three months. The study group consisted of 27 patients, with a mean age of 46.9 +/- 11.1 years. The mean duration of time between the onset of symptoms and the start of this study was 8.1 years. In group 2, no patient had pathologic findings of asthma, and 7/8 had a form of bronchiolitis. There was significant improvement in dyspnea, cough and pulmonary function indices at the end of the 3-month in both groups (p< 0.001). Our results suggest that patients with Intractable asthma could be misdiagnosed and some of them have some forms of chronic bronchiolitis. We believe that any patient who does not respond to standard treatments for Intractable asthma should be evaluated with expiratory HRCT; those with significant air trapping should be considered for a course of macrolide therapy or biopsy for better identification of the underlying disease.