Subcutaneous emphysema: an unusual presentation of foreign body in the airway.

Six children with a foreign body in the airway presented with progressive subcutaneous emphysema as a clinical feature. The aim of this report is to highlight this unusual clinical presentation of foreign body in the tracheobronchial tree. A peculiar arrangement of fascial planes in the neck, chest, and abdomen and an excessive pressure gradient at the alveolar level, facilitates extraalveolar migration of air in the subcutaneous tissue.