Response of mucocutaneous lesions to rituximab in a case of melanoma differentiation antigen 5-related dermatomyositis.

We report the first case in Western Europe of a person presenting with dermatomyositis associated with melanoma differentiation antigen 5 antibodies. She sequentially developed severe mucocutaneous erythematous and itchy lesions of the face, scalp, neck, knees and recurrent aphthae. In addition she presented painful, periungual, edematous digital lesions and small ulcers with digital necrosis. Her rapidly evolving, near-fatal interstitial lung disease responded to high-dose intravenous cyclophosphamide. However, her recurrent mucocutaneous manifestations improved only after rituximab administration.