Cardiac involvement in a case of juvenile dermatomyositis with positive anti-melanoma differentiation associated protein 5 antibody

Juvenile dermatomyositis (JDM) is an autoimmune disease characterized by muscle weakness and specific skin lesions, as well as non-muscular involvement such as interstitial lung disease (ILD), cardiac involvement and arthritis. Anti-melanoma differentiation-associated protein 5 (anti-MDA5)-positive JDM patients are typically characterized by the presence of skin ulcers and rapidly progressing ILD (RP-ILD). Although cardiac involvement is not an expected involvement in anti-MDA5-positive JDM cases, it is significant because it can be fatal. In this report, an anti-MDA5 myositis-specific autoantibody-positive JDM case referred with the diagnosis of psoriatic arthritis in whom cardiomyopathy and arrhythmia were detected in follow-up is presented. Since cardiac involvement is associated with mortality, it would be useful to follow up anti-MDA5 positive patients for cardiac involvement in addition to lung involvement. Tofacitinib is a promising treatment option in treatment-resistant JDM.