Swallowing‑induced spontaneous pneumomediastinum after ingestion of a large, unchewed food bolus in a young adult: a case report

Background Spontaneous pneumomediastinum (SPM) is a rare condition with a generally favorable prognosis, although severe complications, including respiratory arrest or tension emphysema, are reported; swallowing may be an under-recognized precipitating factor. Case presentation A man in his 20s swallowed one‑third of a 10‑cm steamed meat bun without chewing. He developed throat tightness and chest pain without cough and presented to our emergency department. Chest computed tomography (CT) findings revealed extensive mediastinal emphysema; swallowing‑triggered spontaneous pneumomediastinum was diagnosed, and intravenous piperacillin/tazobactam was initiated. Esophagography on day 2 and endoscopy on day 3 showed no leakage or perforation. A CT scan on day 8 revealed near resolution, and he was discharged on day 9 without recurrence. We speculated that the large, unchewed bolus caused transient airway obstruction, leading to a sudden increase in intratracheal pressure and resulting in tracheal or alveolar microinjury. Conclusions This case highlights swallowing of a large, unchewed food bolus as a potential trigger of pneumomediastinum. Considering swallowing‑triggered spontaneous pneumomediastinum in patients presenting with chest pain after eating may facilitate early diagnosis and help avoid unnecessary invasive investigations.