What is polymyositis and dermatomyositis?

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Polymyositis and dermatomyositis: Overview

Polymyositis and dermatomyositis are problems with your immune system. Polymyositis attacks your muscles. Dermatomyositis attacks your skin and muscles.

These problems affect people in different ways. Most people have muscle weakness. Some people also have swelling or pain. Others get a rash.

Your symptoms depend on the muscles that are affected. It may be hard to swallow if your throat muscles are affected. And if your chest muscles are affected, it could be hard to breathe.

Medicines can help with swelling. They may also help control your immune system. Physical therapy and other exercises can also help.


Dermatomyositis is a rare disease that causes inflammation of the skin and muscles. The inflammation can cause an itchy rash and skin thickening, as well as muscle weakness and pain.

Dermatomyositis is an autoimmune disease, in which the body produces antibodies that attack its own tissues. The disease mainly affects middle-aged women. It is treated with medicines to control inflammation and with physical therapy to help relieve muscle problems.

Some people who have dermatomyositis may get better within a few years. Others may have persistent problems that, in some cases, may affect other organs and become severe.

How can you care foryourself when you havepolymyositis and dermatomyositis?

  • You may get different medicines. Some may be for pain and swelling. Others may be for a rash. You may get some to control your immune system.
  • Take your medicines exactly as prescribed. Call your doctor if you think you are having a problem with your medicine.
  • Physical therapy can help keep your muscles strong and flexible. You also may get exercises from a doctor who specializes in diseases of the joints.
  • Talk to your doctor about an exercise program. Activity is important for your muscles, heart, and lungs. If your doctor says it is okay, you may be able to walk, swim, cycle, or take exercise classes. You also may be able to lift weights.
  • If your muscles get very sore, you may want to do less activity or change the type of activity.
  • Use canes, crutches, and any other assistive devices to help you get around.
  • Do not smoke or allow others to smoke around you. If you need help quitting, talk to your doctor about stop-smoking programs and medicines. These can increase your chances of quitting for good.

Polymyositis and dermatomyositis: When to call

Call 911 anytime you think you may need emergency care. For example, call if:

  • It is very hard to breathe or swallow.

Call your doctor now or seek immediate medical care if:

  • Your muscle pain or weakness suddenly gets worse.

Watch closely for changes in your health, and be sure to contact your doctor if:

  • You have side effects from the medicines that help control the immune system. These may include:
    • Weight gain.
    • Mood changes.
    • Trouble sleeping.
    • Bruising easily.
  • You have any other problems with your medicine.

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The content above contains general health information provided by Healthwise, Incorporated, and reviewed by its medical experts. This content should not replace the advice of your healthcare provider. Not all treatments or services described are offered as services by us. For recommended treatments, please consult your healthcare provider.