Plastic Bronchitis

Plastic bronchitis is a rare disorder in which cohesive, branching endobronchial casts form inside the airways, take the shape of the bronchial tree, and obstruct ventilation. A cast may involve one segment, an entire lobe, or a whole lung. Some patients cough up an intact, rubbery cast that visibly reproduces the airway anatomy; others retain the cast and present with sudden respiratory compromise. The obstruction is mechanical, not simply an excess of ordinary sputum. That distinction changes the priority: oxygen can support gas exchange, but it cannot remove a cast sealing a central bronchus. Acute central obstruction is the principal cause of death. Modern classification asks why the cast formed. In lymphatic plastic bronchitis, abnormal lymphatic flow allows lymph to enter the pulmonary airways. In eosinophilic or inflammatory plastic bronchitis, type 2 airway inflammation generates an eosinophil-rich scaffold. The older Seear type I and type II labels are less useful because they can obscure these mechanisms. Causes include Fontan, Glenn, or Blalock–Taussig palliation for congenital heart disease; infection; asthma, atopy, and eosinophilic pneumonia; allergic bronchopulmonary aspergillosis; sickle cell acute chest...