Dermatomyositis Disease

Dermatomyositis (DM) is a long term inflammatory disorder which affects muscles. Symptoms generally a skin rash and worsening muscle weakness over time. Symptoms may occur suddenly or develop over months. Other symptoms may include weight loss, fever, lung inflammation, or light sensitivity. Complications may include calcium deposits in muscles or skin. The cause is unknown. Theories include that it is an autoimmune disease or a result of a viral infection. It is a type of inflammatory myopathy. Diagnosis is typically based on some combination of symptoms, blood tests, electromyography, and muscle biopsies.