Pneumomediastinum and pneumoretroperitoneum.

A 23-year-old man presented to the emergency department with extensive subcutaneous emphysema and severe dehydration after a prolonged self-imposed religious fast. Chest radiographs showed marked pneumomediastinum and pneumoretroperitoneum without pneumothorax. Patients are often admitted to the hospital for close observation when these findings are recognized, but this caution is generally unwarranted. This case illustrates the common occurrence of the usually benign entity of pneumomediastinum without pneumothorax.