Polymyositis Definition

Polymyositis is a rare, incurable disease of the connective tissues, characterized by weakness of the muscles of the skeleton. A chronic, potentially debilitating disease, polymyositis can be controlled with a combination of therapies recommended by a health care provider.

The Facts

• Polymyositis is an inflammatory myopathy. This inflammation and weakness of the skeletal muscles develops gradually and occurs mostly in adults between the ages of 30 and 60, although it can affect people of any age. African-Americans and women are affected most by polymyositis.

Symptoms

• Polymyositis develops gradually, with spontaneous remission, making it difficult to notice the onset. Since the primary symptom of polymyositis is weakness in the muscles nearest to the torso, the symptoms of polymyositis may be attributed to other factors.

  As the disease progresses, performing tasks such as climbing stairs, lifting or reaching overhead, or even rising from a chair may become difficult.

  Other symptoms of polymyositis include difficulty swallowing or speaking, tenderness of joints or muscles, fatigue and shortness of breath

Causes

• Like most diseases and disorders of the muscles, the cause of polymyositis is unclear.

  Genetics may be a factor in polymyositis and other inflammatory myopathies, as are
  bacterial, viral and parasitic infections.

  It is speculated that inflammatory myopathies such as polymyositis are caused when the immune system produces antibodies that attack the muscles and tissues. This speculation is based in research on polymyositis sufferers who have autoantibodies in their bloodstream.

Diagnosis

• Polymyositis can be challenging to diagnose. However, doctors now have several tools to detect polymyositis, including magnetic resonance imaging, which can detect inflammation in the muscles without invasive tests. Muscle tests such as electromyography and muscle biopsy allow for study of specific muscles. Blood analysis will determine any elevation of muscle enzymes that are indicative of damage to the muscle, while additionally detecting the presence of autoantibodies which are associated with polymyositis.

Treatment

• Doctors often treat polymyositis with a range or combination of drugs and other therapies that not only treat the symptoms of this disease, but also improve functioning. Drugs that suppress the immune system, therefore reducing the production of antibodies that may be attacking the muscles, are often used. Most often, these drugs include corticosteriods such as prednisone.

  Other drugs may be prescribed to alleviate the symptoms caused by steroid treatment.

  To improve muscle function and address functional disabilities resulting from polymyositis, a doctor may prescribe physical therapy and speech therapy, as well as dietetic consultation.