Background: Post-infectious bronchiolitis obliterans (PIBO) in young children is a rare but severe obstructive airway disease. Oral prednisolone treatment potentially improves outcome in these patients. Methylprednisolone pulse therapy (MP) may be a good alternative with beneficial effects but fewer side effects than daily treatment with oral corticosteroids.

Aim: To describe the effect of MP on symptoms, exacerbations, and CT scan abnormalities in children with PIBO.

Methods: This longitudinal, observational registry-based study included children with a new diagnosis of PIBO, followed at an academic hospital in the Netherlands according to the standard of care protocol. Data on clinical characteristics, bronchoscopy and CT scan abnormalities was collected. Clinical evaluation and CT scan was repeated after treatment with MP for 3 consecutive days over 3 consecutive months.

Results: From the 10 children (mean age 25.5 ±11.5 months) with newly diagnosed PIBO, bronchoscopy showed an anatomical anomaly (trachea or bronchomalacia) in 5, diffuse inflammation in 7 and positive culture for micro-organisms in 5. None of these 10 children showed immunodeficiencies. After MP treatment, 6 out of 10 children showed clinical improvement, and 5 of these 6 children showed improvement on the CT scan. The main side effects were hypertension and hyperglycemia, which resolved after discontinuation of therapy.

Conclusion: This study demonstrates a positive effect of MP on symptoms and/or structural CT scan abnormalities in children with PIBO. Expanding the registration platform to other hospitals will enhance our knowledge and help to standardize diagnostics and treatment of this disease.