Association of dermatomyositis and autoimmune hepatitis: A case report.

The association of dermatomyositis (DM) and autoimmune hepatitis (AIH) is rare and presents a diagnostic and therapeutic challenge. We describe the case of a 36-year-old man with DM diagnosed in 2012 and treated with corticosteroid and methotrexate. The patient achieved total remission 18 months later. In 2022, an AIH was diagnosed (cytolysis, cholestasis, anti-LC1, and anti-SLA antibodies) while DM was in remission. Liver function normalized after two months of treatment with mycophenolate mofetil and corticosteroids. Liver damage in systemic autoimmune diseases can result from viral, iatrogenic, or autoimmune processes. The association between DM and AIH is exceptional and has only been documented in one previous observation. Autoantibodies are essential for diagnosing and managing patients with inflammatory myopathy and AIH. In conclusion, this exceptional association of AIH and DM raises many questions regarding the presence of etiopathogenic links, such as genetic predisposition, autoimmunity disorders, viral infection triggers, or simply a happenstance.