Dermatomyositis Flare With Immune Checkpoint Inhibitor Therapy for Melanoma

Immune checkpoint inhibitor (ICI) medications have seen expanded use in the management of numerous malignancies. These therapies encompass a unique spectrum of immune-related adverse events (irAEs). Rheumatological irAEs from ICIs have been described in various case reports; however, limited literature exists regarding the treatment of patients with pre-existing myositis. We describe a case of myositis flare after initiation of nivolumab for metastatic melanoma in a patient who had previously achieved remission of dermatomyositis.