Dermatomyositis (DM) is a connective-tissue disease related to polymyositis (PM) that is characterized by inflammation of the muscles and the skin. While DM most frequently affects the skin and muscles, it is a systemic disorder that may also affect the joints, the esophagus, the lungs, and the heart. In the United States, the incidence of DM is estimated at 5.5 cases per million people.

Read full article on Wikipedia · CC-BY-SA