Purpose: Plastic bronchitis (PB), a rare complication of respiratory infection characterized by the formation of casts in the tracheobronchial tree, can lead to airway obstruction and severe condition. Adenovirus is one of the common pathogens of PB caused by infection. This study aimed to evaluate the clinical features and risk factors for PB in children with severe adenovirus pneumonia.
Methods: A retrospective study of children with severe adenovirus pneumonia with bronchoscopy results at Guangzhou Women and Children’s Hospital between January 2018 and January 2020 was performed. Based on bronchoscopy, we divided children with severe adenovirus pneumonia into two groups: PB and non-PB. Binary logistic regression analysis was used to identify independent risk factors for PB in patients with severe adenovirus pneumonia after univariate analysis.
Results: Our study examined 156 patients with severe adenovirus pneumonia with bronchoscopy results in hospital. Among them, 18 developed PB and 138 did not. On multivariate analysis, the independent risk factors of PB in children with severe adenovirus pneumonia were history of allergies (OR 10.147, 95% CI 1.727– 59.612; P=0.010), diminished breath sounds (OR 12.856, 95% CI 3.259– 50.713; P=0.001), and increased proportion of neutrophils (> 70%; OR 8.074, 95% CI 1.991– 32.735; P=0.003).
Conclusion: Children with severe adenovirus pneumonia with a history of allergies, diminished breath sounds, and increased the proportion of neutrophils > 70% may show higher risk of PB.

Keywords: plastic bronchitis, severe adenovirus pneumonia, risk factors, children