Spontaneous pneumomediastinum: An uncommon presentation of anti-MDA5-positive dermatomyositis

Abstract

Anti-MDA5 positive dermatomyositis (anti-MDA5+ DM) is a rare subtype of dermatomyositis, often associated with rapid-progressive interstitial lung disease (RP-ILD), leading to significantly higher mortality. Spontaneous pneumomediastinum, although rare, is a potentially fatal manifestation of this condition and could also be a predictor of RP-ILD and associated with worse outcomes. A 41-year-old man initially presented with spontaneous pneumomediastinum leading to desaturation, proximal muscle weakness, Gottron’s papules, and the “V sign” on his neck. Testing confirmed the presence of MDA5 antibodies, diagnosing anti-MDA5+ DM. He was treated conservatively for pneumomediastinum and started on immunosuppressive therapy. Long-term management includes regular adjustment of immunosuppressive medications and follow-up with High-Resolution Computed Tomography (HRCT) and pulmonary function tests due to the risks of RP-ILD and recurrent spontaneous pneumomediastinum. This case highlights the importance of thoroughly evaluating patients with spontaneous pneumomediastinum for signs of autoimmune disease and myositis profile. Early diagnosis and aggressive treatment are essential to reduce complications and improve outcomes in anti-MDA5+ DM patients.

Keywords: Spontaneous pneumomediastinum, anti-MDA5 positive dermatomyositis, RP-ILD