Nuclear matrix protein 2 antibody-positive adult dermatomyositis: a case report and review of the literature.

Dermatomyositis is a clinically heterogenous inflammatory myopathy with unique cutaneous features. Myositis-specific antibodies can aid in diagnosis and anticipation of patient prognosis. Herein, we report a 22-year-old man who presented with multifocal erythematous plaques with violaceous papules on his bilateral elbows, neck, and face. He was diagnosed with biopsy-proven dermatomyositis and determined to be seropositive for nuclear matrix protein 2 antibody (NXP-2). He was treated with systemic corticosteroids, then intravenous methylprednisolone and azathioprine, and ultimately achieved greatest treatment response with intravenous immune globulin therapy.