Introduction Post–infectious Obliterative bronchiolitis (OB) has multiple aetiologies with adenovirus the most common cause in the UK. Children with OB usually present with respiratory symptoms and features of small airway obstruction. High resolution CT may show variable small airway obstruction and paucity of vascular markings to support the diagnosis. Treatment is supportive. No published studies have reported the medium term prognosis of OB in UK children.

Methods We describe the clinical course of OB in 19 patients followed for up to 5 years after diagnosis. Data on symptoms, lung function, microbiology, imaging and treatment were collected.

Results Median age at diagnosis was 4 years (range 1–11 years, 8 boys). Productive cough was common in up to 70% and wheeze occurred in 20%. Adenovirus was the most common cause identified (9 patients), followed by idiopathic (7 patients). CT confirmed diagnosis and repeat showed no change in 3, improvement in 2 and worsening in 2. Seven children had repeat FEV₁ measurements, of those 4 had an improvement (increase in% predicted FEV₁ 4–25%). 69% of the cohort received prophylactic winter antibiotics and on average had an additional 2 treatment courses /year. Chest physiotherapy was used in all children, mainly during exacerbations. 3 patients required supplementary oxygen and BIPAP which we were able to discontinue by year 5. 1 teenage boy received a lung transplant.

Conclusion Our cohort has been defined. This is a heterogeneous group with a variable course in disease. An improvement in disease outcome may be possible in some patients with effective treatment. However a national multicentre follow- up longer term study would help to define characteristics and prognosis on a population level.