Spontaneous pneumomediastinum in dermatomyositis: a case series and literature review

OBJECTIVES: To describe a case series of spontaneous pneumomediastinum in dermatomyositis and to review the literature.METHODS: This was a retrospective single-center case series, reporting 9 patients with pneumomediastinum and defined dermatomyositis, followed from 2005 to 2017.RESULTS: Median age of patients: 33 years; cutaneous and pulmonary involvement in all cases; constitutional symptoms in 88.8% of patients; involvement of the joints in 11.1%, gastrointestinal tract in 44.4%, and muscles in 77.7%; subcutaneous emphysema was observed in 55.5% and pneumothorax in 11.1%, respectively.Muscle weakness was observed in 77.7% of cases and with a median level of serum creatine phosphokinase of 124U/L.Drawing on results for our literature review, the overall analysis showed that the risk factors associated with spontaneous pneumomediastinum were: (a) a history of interstitial pneumopathy; (b) normal or low levels of muscle enzymes; (c) previous use of systemic glucocorticoid; (d) over 50% of patients had subcutaneous emphysema; (e) high mortality as a consequence of severity of the interstitial lung disease.CONCLUSIONS: Our case series revealed that pneumomediastinum is a rare complication in dermatomyositis that occurs in patients with a history of interstitial pneumopathy and may be accompanied by subcutaneous emphysema and pneumothorax.