A rare cause of crepitus.

Accepted 25 June 1997 A 52-year-old man presented to Accident and Emergency complaining of pain in his right upper chest and right arm which he attributed to falling out of bed approximately 36 hours earlier. On examination he was apyrexial, normotensive and mildly tachypnoeic. His right upper arm and chest were swollen and crepitant to palpation. There were no open wounds. Chest examination was otherwise unremarkable. His chest radiograph (figure 1) showed no evidence oflung collapse. The lucent areas along fascial planes and rib fractures in the upper thorax were thought to confirm that a resolving pneumothorax was responsible for the apparent subcutaneous emphysema. He was admitted for observation but within an hour the appearance of his right arm had deteriorated dramatically (figure 2).