Polymyositis

Polymyositis is a rare disease of the muscles. It usually affects the muscles closest to the trunk of the body. However, it may affect muscles anywhere in the body. The muscles become inflamed or swollen. This causes pain. The disease is progressive and starts slowly. If untreated, the muscles gradually become weaker. The pain in the muscles also increases.

  • Causes

    Polymyositis may be caused by a combination of genetic and environmental factors that trigger an abnormal immune response.

  • Definition

    Polymyositis is a rare disease of the muscles. It usually affects the muscles closest to the trunk of the body. However, it may affect muscles anywhere in the body. The muscles become inflamed or swollen. This causes pain. The disease is progressive and starts slowly. If untreated, the muscles gradually become weaker. The pain in the muscles also increases.

    Front Muscles of Trunk
    Trunk Core Muscles
    Copyright © Nucleus Medical Media, Inc.

  • Diagnosis

    This diagnosis is not easy. Symptoms vary from person to person. It is often a matter of ruling out other diseases and conditions. Your doctor will ask about your symptoms and medical history. A physical exam will be done.

    Tests may include the following:

    • Blood tests to check for elevated muscle enzymes and autoimmune antibodies
    • Electromyogram
      (EMG) to measure muscle activity

    • Muscle
      biopsy


    Imaging tests take pictures of internal body structures to look for muscle inflammation. This can be done with an
    MRI
    .

  • Prevention

    There are no current guidelines to prevent polymyositis.

  • Risk Factors

    Polymyositis is more common in women, and in people aged 31-60 years old.

  • Symptoms

    Polymyositis may cause:

    • Muscle weakness
    • Muscle pain
    • Fatigue
    • Great effort needed to climb stairs
    • Trouble rising from a chair
    • Difficulty reaching overhead
    • Chronic dry cough

  • Treatment

    While there is no cure, treatment can improve your muscle strength and function. Talk with your doctor about the best plan for you. Options include: