Dermatomyositis is a “connective tissue disease” that causes inflammatory changes in the muscle and a skin rash. The cause is unknown. It usually starts with an itchy, burning, reddish or bluish rash on areas that have been exposed to the sun. As the disease progresses, there is muscle weakness. The arm and thigh muscles are most affected. You may have a hard time climbing stairs, getting out of chairs, lifting heavy things, or raising the arms overhead. Sometimes the muscles ache and become tender. The swallowing muscles may also be affected.

This condition is treated with oral steroids to slow down the disease's progression. Other medicines may also be used. Depending on various factors, steroid-sparing drugs such as azathioprine or methotrexate may be started at the same time as oral steroids to prevent some of the complications of long-term steroid use. In some cases, these drugs may only be used if you fail oral steroid treatment. Some patients (20%) will recover completely. Others will need treatment over their lifetime.

Dermatomyositis may be associated with a higher risk of certain types of cancer (ovarian, stomach, lymphoma). Your doctor may do periodic screening exams.

Home care

The following guidelines will help you care for yourself at home:

  • The rash is sensitive to sun exposure. Use sun protection (hats, cover-up clothing) and sunscreen (at least SPF 15).

  • If you have muscle aches, rest as needed.

  • Light exercise and physical activity can help keep your muscles in the best shape possible. Talk to your doctor about an exercise plan that is right for you. Your doctor may have you see a physical therapist.

  • You may use acetaminophen or ibuprofen to control pain, unless another medicine was prescribed. [NOTE: If you have chronic liver or kidney disease or ever had a stomach ulcer or GI bleeding, talk with your doctor before using these medicines.] Don’t take ibuprofen or other NSAID (nonsteroidal anti-inflammatory) medicine if you were prescribed prednisone.

  • Talk with your doctor before trying to get pregnant.

Follow-up care

Follow up with your doctor or as advised by our staff. For more information contact:

  • Myositis Association

  • Arthritis Foundation 

When to seek medical care

Get prompt medical attention if any of the following occur:

  • Shortness of breath, weakness, dizziness

  • Pain in abdomen

  • Vision changes

  • Change in bowel or bladder habits

  • Blood in the stool (black or red color)

  • Unexpected weight loss

  • Thickening or lump in the breast or elsewhere

  • Difficulty swallowing

  • Cough or hoarseness that doesn't go away

  • Fever of 100.4ºF (38ºC) or higher, or as directed by your health care provider