摘要Introduction::Anti-melanoma differentiation-associated gene 5-positive dermatomyositis (anti-MDA5 + DM) is a distinct subtype of DM, which is characterized by typical cutaneous features, minimal or no muscle involvement and notable interstitial lung disease, which typically progresses rapidly and has a high mortality. Spontaneous pneumomediastinum (PNM), a relatively unusual but serious complication of anti-MDA5 + DM, further increases mortality. Currently, there is no generally accepted treatment regimen for anti-MDA5 + DM-associated PNM. Case Description::A 53-year-old man with anti-MDA5 + DM presented with rapidly progressive interstitial lung disease that progressed to diffuse subcutaneous emphysema and PNM despite aggressive immunosuppressive therapies. He responded well to combined anti-infection treatments, moderate immunotherapy, and continuous oxygen therapy. Conclusion::Comprehensive screening for potential infections, as well as close monitoring of the patient's immune status is essential for individualizing treatment and maximizing prognosis.