A Clinical Picture of Amyopathic Dermatomyositis

Clinically amyopathic dermatomyositis (CADM) is a rare subset of classic dermatomyositis (DM) with distinct clinical features and unique autoantibody profiles. Affected individuals usually present with the cutaneous signs of DM, without muscle pain, proximal weakness, or abnormal muscle labs and imaging results. Here, we present the case of a 69-year-old Caucasian male for evaluation of a positive antinuclear antibody (ANA) test and an eight-month history of a rash. He had no associated muscle weakness or pain. A physical examination noted a rash characteristic of dermatomyositis, including pathognomonic Gottron's papules. Skin biopsies were inconclusive, and labs were negative for anti-Jo1 antibodies or elevated muscle enzymes. Treatment was first initiated with hydroxychloroquine before ultimately being switched to methotrexate, which was more effective for him.