[A PEDIATRIC CASE OF DIFFUSE PANBRONCHIOLITIS WHO PREDOMINANTLY SHOWED RESTRICTIVE PULMONARY DYSFUNCTION AND DRAMATICALLY RESPONDED TO MACROLIDE LOW-DOSE LONG-TERM THERAPY.].

A 12-year-old boy visited our hospital with complaints of chronic cough and dyspnea. Chest X-ray and CT revealed diffuse granular shadow in the bilateral lung fields and "Tree-in-bud appearance" in the peripheral airways, respectively. Sinusitis was present, and restrictive disorder was predominantly found in pulmonary function. The patient was diagnosed with DPB, and long-term therapy was started with low-dose clarithromycin (CAM), The patient showed a dramatic response to CAM, with improvements of both the clinical symptoms and pulmonary function within 1-2 months. According to the relevant literature, in adult patients with this disease, pulmonary dysfunction starts from an obstructive pattern; however, this is not the case in pediatric patients. It was therefore suggested that the mechanisms underlying the development of pulmonary dysfunction in cases of childhood onset differs from those with an adult onset.