Idiopathic Spontaneous Pneumomediastinum in an Adolescent.

Idiopathic spontaneous pneumomediastinum (ISPM) is a diagnosis of exclusion after a spontaneous pneumomediastinum (SPM) occurs without any identifiable predisposing factors or known aetiology. It is a rare diagnosis in adolescents, with a few cases reported in the literature. To increase awareness of this rare diagnosis, we present a case of a 17-year-old, fit and healthy male who presented with acute atraumatic chest pain. On examination, surgical emphysema in the supraclavicular fossa was identified. His chest X-ray and a subsequent computed tomography (CT) of the thorax showed extensive pneumomediastinum, with infiltration of air into the soft tissues of the neck and upper arms, but with no identifiable cause. On follow-up, he remained asymptomatic, and a repeat CT of the thorax four weeks after his initial presentation showed complete resolution of the pneumomediastinum. Once confirmed, ISPM is expected to resolve spontaneously without complications, with a very low rate of recurrence in nearly all cases.