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By Mayo Clinic staffDermatomyositis (dur-muh-to-mi-uh-SI-tis) is an uncommon disease marked by muscle weakness and a distinctive skin rash. It's a type of inflammatory muscle disease — "myo" means "muscles" in Greek; "itis" means "inflamed." "Derma," which means "skin," refers to the skin-related symptoms that accompany the muscle inflammation of dermatomyositis.
Dermatomyositis may occur at any age, but it mostly affects adults in their late 40s to early 60s or children between 5 and 15 years of age. Women have dermatomyositis more often than men do. Dermatomyositis usually develops over weeks or months.
Periods of remission, when symptoms of dermatomyositis improve spontaneously, may occur. Treatments can improve your skin and your muscle strength and function.
Symptoms