Spontaneous pneumomediastinum: a rare cause of acute chest pain.

A patient in late adolescence presented with sudden pleuritic chest pain at rest. Chest radiograph showed pneumomediastinum with associated subcutaneous emphysema. CT thorax with oral contrast confirmed spontaneous pneumomediastinum (SPM) and excluded oesophageal or tracheobronchial injury. SPM occurs when alveolar rupture allows air to track along perivascular sheaths into the mediastinum, known as the Macklin effect. The patient remained clinically stable during hospital observation and required only simple analgesia. A repeat chest radiograph showed no progression. The patient was discharged without complications. This case emphasises the need to consider pneumomediastinum in otherwise healthy individuals presenting with acute chest pain.