Postinfectious Bronchiolitis Obliterans Misdiagnosed as Bronchial Asthma in a Pediatric Patient

Bronchiolitis obliterans is a chronic obstructive respiratory disease involving stenosis or occlusion of the bronchioles and smaller airways. The prognosis of bronchiolitis obliterans is poor, and the patient might require home oxygen therapy and/or lung transplantation. Bronchiolitis obliterans has various etiologies; in children, the most common causes are infections by respiratory pathogens like adenoviruses. In such cases, the condition is termed as postinfectious bronchiolitis obliterans. A 7-year-old girl was diagnosed with bronchial asthma at the age of 1 year and was on a regimen of a leukotriene receptor antagonist and an inhaled corticosteroid. At 1 year of age, she was admitted to our hospital with a respiratory syncytial virus infection, and despite continued treatment with the above drugs, she required frequent readmissions. At the age of 7 years, she was diagnosed with postinfectious bronchiolitis obliterans based on the following findings: mosaic perfusion on high-resolution chest computed tomography and ventilation-perfusion mismatch on ventilation-perfusion scintigraphy. A lung biopsy was not performed due to its invasiveness. It has been suggested that appropriate treatment during the early stage improves the prognosis of bronchiolitis obliterans. This disease might be misdiagnosed as bronchial asthma because of the clinical similarities. In patients who do not respond to the treatment for bronchial asthma, pediatricians should consider other diseases with similar signs and symptoms, such as bronchiolitis obliterans, in the differential diagnosis.