Clinical characteristics of bronchiolitis obliterans without preceding severe lower respiratory tract infection

ABSTRACT

Purpose@#We investigated young children who developed bronchiolitis obliterans (BO) without preceding severe lower respiratory tract infection (LRTI). @*Methods@#Twenty patients referred for chronic respiratory symptoms and diagnosed with BO were enrolled and divided into 2 age groups group 1 ( < 2 years, n = 12) and group 2 ( ≥ 2, < 6 years, n = 8). A diagnosis of BO was made based on clinical and radiologic findings: (1) persistent cough or abnormal breath sounds which were not responsive to any treatment for more than 6 weeks; and (2) mosaic perfusion on high-resolution computed tomography. None of the subjects had experienced LRTI since birth, and those who had any underlying problems were excluded. The clinical characteristics and disease course were examined retrospectively. @*Results@#Mean age of the patients was 6.8 months and 3.4 years in group 1 and 2, respectively. All patients presented with chronic cough and the most common type of cough was mixed (wet and dry), 67% in group 1 and 50% in group 2. Persistent stridor was the major respiratory sign in group 1 (67%), but 63% of group 2 patients showed no abnormal breath sounds. Chest x-ray finding was nonspecific in 75% each of both groups. The respiratory symptoms and signs resolved rapidly in most patients treated with pulse corticosteroid therapy. Bronchial hyperresponsiveness and decreased forced expiratory volume in 1 second were observed in 3 of group 2 children at age 6, during the follow-up. @*Conclusion@#Our study shows that BO could develop without preceding severe LRTI. It also suggests that BO should be considered in the infants with persistent stridor accompanied by chronic cough.