OBJECTIVETo analyze the clinical characteristics, image findings, laboratory examination, the therapeutic methods and clinical outcomes of bronchiolitis obliterans (BO) in pediatric patients.

METHODTwenty-six pediatric patients with BO were reported. All data were collected from cases who were hospitalized in the Department of Pediatrics, First Affiliated Hospital of Guangzhou Medical College from June 1(st), 2009 to the April 30(th), 2011, and infectious agents, clinical manifestations, risk factors, changes in imageology, laboratory examination, therapeutic methods and treatment responses were analyzed.

RESULTThe ranges of age at onset was 4.5 months-8 years in 26 cases (18 boys and 8 girls). The course of disease was (6.2 ± 3.5) months. The period of followed-up ranged from 2 to 24 months. The common clinical characteristics were persistent wheezing of different severity (26 cases, 100%), cough (24 cases, 92%), intolerance to exercise (22 cases, 85%), short of breath (21 cases, 81%), retraction (20 cases, 77%), wheezy phlegm (16 cases, 62%), keeping with crackles (10 cases, 38%), cyanosis around the mouth (3 cases, 12%) and no clubbed fingers (toes). In 18 cases the etiology was detected, mycoplasma (11 cases, 42%), respiratory syncytial virus (4 cases, 15%), parainfluenza virus (2 cases, 8%), influenza virus A (2 cases, 8%) and influenza virus B (2 cases, 8%), human bocavirus (HBoV) (1 case, 4%). There were 8 cases (31%) with combined infection. Chest X-ray in 10 cases indicated changes suggestive of bronchopneumonia (38%), in only 1 case there was an image of interstitial pneumonia disease (4%). All the patients were diagnosed by high-resolution computerized tomography (HRCT). All cases were demonstrated to have air retention, poor blood perfusion in lung, just like "Westemark sign" with HRCT. In 19 cases antineutrophil cytoplasmic antibody (ANCA) was determined and 10 patients (53%) were positive for P-ANCA, and 8 cases (42%) were positive for C-ANCA. All patients received oral corticosteroid and low doses azithromycin. In 13 cases (50%) the treatment effectively reduced the severity of disease and the frequency of cough and wheezing. The average number of days for symptom improvement was (7.1 ± 4.8) days.

CONCLUSIONRespiratory infection plays an important role in BO in children. The chronic and persistent wheezing, cough, intolerance to exercises, short breath, retraction were the main clinical manifestations. But these symptoms are non-specific. Chest X-ray can not provide enough information for diagnosis. Classical "Westemark sign" with HRCT is an important sign. ANCA with a high positive rate (approximately 50%) suppose immuno-lesion in BO. Oral corticosteroid and methotrexate may relieve clinical symptoms.