Spontaneous primary pneumomediastinum: is it always benign?

Background Spontaneous Pneumomediastinum is a rare disease. It could be a simple and self-limited condition or be a life-threatening complication of underlying diseases. The therapeutic options also differ by the cause. This systematic review was done to provide, as far as we know, the first attempt to broadly assess the clinical feature, predisposing factors, possible management, and outcome of spontaneous primary pneumomediastinum. Methods In addition to the two patients treated at our hospital, a Pub Med Search for literature on case reports of spontaneous pneumomediastinum published in English up to November 2018 was done. We extracted data on patients' demographic characteristics, symptoms, timing, diagnosis, management, and outcome of the treatment were analyzed based on the preferred Reporting Items for Systematic reviews and Meta-analysis (PRISMA) Result A total of 339 cases were reviewed. 71.7% of them were male. The Mean age affected was 22.4 +/- 11.3 years. Chest pain, 196 (57.8%), is the most common presenting symptom, followed by dyspnea, 156 (46%), cough 95 (28%), neck swelling 92 (27.13%), cervical pain 88 (25.9%), dysphagia 39 (11.5%), odynophagia 37 (10.9%), and Dysphonia 14 (4.1%). Fifty-seven patients (16.8%) had a prior history of Asthma, 19 (5.6%) had Connective Tissue Disorders, and 12 (3.5%) had associated malignancy as an identified risk factor. In 35 (10.3%) patients, spontaneous pneumomediastinum was found incidentally. The mean number of days before the clinical resolution of spontaneous pneumomediastinum was 6.65 +/- 11.8 days and the average hospital stay was 4.15 +/- 1.93 days. Nineteen (5.6%) patients have died as a result of the underlying disease not related to SPM. Conclusion Spontaneous pneumomediastinum is uncommon, usually benign, a self-limited disorder that commonly occurs in a young adult without any apparent precipitating factor or disease. Spontaneous pneumomediastinum usually responds very well to conservative treatment without recurrence. However, secondary causes should be ruled out to minimize the unfavorable outcome.