The differential diagnosis of persistent wheezing in a child classically includes asthma, gastroesophageal reflux, anatomical abnormalities, and cardiac failure. Bronchiolitis obliterans is a rare but important consideration in the workup of the wheezing patient.

We report two children with wheezing since infancy and a diagnosis of asthma. Pt A is 13 year-old male with recurrent episodes of wheezing since 7 months of age. His wheezing was aggravated by exercise, but did not occur at night. His symptoms worsened and became persistent despite aggressive treatment with inhaled steroids and beta agonists. Pulmonary function tests revealed FVC 67%, FEV1 37%, FEV1:FVC 68%, PEFR 33%, FEF 25-75 15%. There was no significant change post-bronchodilator treatment. CXR was unremarkable. Patient B is a 6 year-old girl who presented with wheezing at 8 months of age following viral respiratory infections. She had poor response to oral steroid bursts and bronchodilator therapy and her symptoms became a daily problem. Pulmonary function tests showed FVC 48%, FEV1 35%, FEV1:FVC 68%., PEFR 37%, FEF 25-75 48%. CXR revealed only hyperinflation.

Chest CT of Pt A demonstrated bronchiectasis of the large airways with narrowing and fibrosis of the small airways, consistent with bronchiolitis obliterans. Chest CT of Pt B showed bilateral emphysema with bronchiectasis.

We present two cases of Bronchiolitis Obliterans masquerading as severe persistent asthma. CT scans are an important part of the evaluation because CXR may be normal and early diagnosis may allow for aggressive treatment.