Inflammatory Myopathies
Inflammatory myopathies are a group of muscle diseases involving the inflammation and
degeneration of skeletal muscle tissues. They are thought to be autoimmune disorders. In
inflammatory myopathies, inflammatory cells surround, invade, and destroy normal muscle
fibers as though they were defective or foreign to the body. This eventually results in
discernible muscle weakness. This muscle weakness is usually symmetrical and develops
slowly over weeks to months or even years.
Types of Inflammatory Myopathies
The inflammatory myopathies include dermatomyositis, polymyositis, and inclusion body
myositis. Although all of these diseases result in muscle weakness, each is unique in its
development and treatment.
Symptoms of Inflammatory Myopathies
Early signs of inflammatory myopathies may include difficulty rising from a chair,
climbing stairs, or lifting the arms. A patient may become exceedingly fatigued after
prolonged standing or walking. In some cases, early signs may include difficulty in
swallowing or breathing.
Diagnosis of Inflammatory Myopathies
Your physician may run a number of tests, including a physical examination, blood
tests, electromyography (EMG) and a muscle biopsy. The diagnosis is confirmed by the
muscle biopsy using special stains. Electron microscopy of the muscle may be necessary. If
a polymyositis patient does not respond to treatment it is important that he/she see a
specialist to rule out IBM. At times a repeat muscle biopsy may be necessary.
Treatment of Inflammatory Myopathies
High dose prednisone (an immunosuppressant) has been an effective treatment for many
patients. Other immunosupressants such as azathioprine and methotrexate are often used.
Unfortunately, these drugs have adverse side effects, especially after prolonged use. For
patients who do not respond well to prednisone, intravenous administration of
immunoglobulins (IVIg) has also proven effective. |
