Unilateral "white lung" in a child revealing plastic bronchitis: A reversible cause of airway obstruction.

Plastic bronchitis is a rare cause of airway obstruction in children and may mimic severe pulmonary disease on imaging. We report the case of a 2-year-5-month-old boy admitted with prolonged febrile respiratory distress and complete opacification of the left hemithorax on chest radiography. Chest computed tomography suggested extensive left pulmonary involvement, initially raising concern for advanced postobstructive pulmonary damage and foreign body aspiration. Flexible bronchoscopy subsequently revealed extensive bronchial casts obstructing the left bronchial tree, which were successfully removed. Histopathological examination demonstrated acellular mucinous casts consistent with type II plastic bronchitis. Clinical and radiological improvement was rapid following bronchoscopic extraction, and no underlying cardiac, infectious, immunological, or lymphatic cause was identified. This case highlights plastic bronchitis as a rare but reversible cause of unilateral "white lung" in children and emphasizes the pivotal role of early bronchoscopy in establishing the diagnosis, guiding management, and avoiding unnecessary invasive procedures.