Dermatomyositis (dur-muh-toe-mi-uh-SY-tis) is an inflammatory muscle disease that weakens muscles and produces a distinctive skin rash.

More to Know

Dermatomyositis, a type of inflammatory myopathy, can occur at any age, but is most common in children age 5-15 and adults age 40-60. Females are more likely than males to develop this rare condition.

No one knows exactly what causes dermatomyositis, but it's thought to be an autoimmune disorder in which antibodies attack small blood vessels in the muscle. Viral infections and certain cancers can also lead to the disease.

The first sign of dermatomyositis usually is a patchy purple and red skin rash that appears on the eyelids, face, knuckles, neck, chest, shoulders, back, elbows, knees, and ankles. Other symptoms include progressive muscle weakness, shortness of breath, muscle and joint pain, difficulty swallowing, fatigue, fever, and weight loss. Some people, especially children, may develop hardened deposits of calcium under the skin (calcinosis).

Dermatomyositis cannot be cured, but it can be treated with anti-inflammatory and immunosuppressant medications, as well as intravenous gamma globulin (a donated blood product with healthy antibodies).

Keep in Mind

Dermatomyositis is a serious disease that can result in life-threatening complications such as cancer, heart disease, lung disease, and pneumonia. With treatment, however, most people can see improvement in their condition. Some people may even experience short-term or long-term remission (an absence of symptoms).

All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.