What is Dermatomyositis/Polymositis?
What is Dermatomyositis/Polymositis?
Polymyositis and Dermatomyositis are inflammatory muscle disease that causes varying degrees of decreased muscle power. Dermatomysitis also involves the skin but polymyositis does not. With dermatomyositis, you develop a violet or deep reddish-purple rash. The disease has a gradual onset and generally begins in the second decade of life. Polymyositis rarely affects persons under the age of 18. The most common symptom is muscle weakness, usually affecting those muscles that are closest to the trunk of the body (proximal). Eventually, patients have difficulty rising from a sitting position, climbing stairs, lifting objects, or reaching overhead. In some cases, distal muscles (those not close to the trunk of the body) may also be affected later in the course of the disease. Trouble with swallowing (dysphagia) may occur. In some patients, the muscles ache and are tender to touch. The disease may be associated with other collagen, vascular, autoimmune, or infectious disorders.
Symptoms can begin suddenly or slowly and may include:
- weakness, especially in the hips, thighs, upper arms, and shoulders
- muscle and joint pain
- weight loss
- fatigue
- fever
- tremors of the hands
- shortness of breath, even at rest
- problems swallowing.
If you have dermatomyositis, you also have a violet or deep reddish-purple rash.
The inflammation can also weaken the heart muscle. The heart can’t squeeze as well, and congestive heart failure may develop. Congestive heart failure is the buildup of fluid in body tissues that can happen when the heart is not working well. The disease also may cause heart rhythm irregularities and very fast heart rates. Inflammation of the pericardial sac, which surrounds the heart, may cause some fluid buildup inside the sac.
How is it diagnosed?
Your rheumatologist will ask about your medical history and your symptoms. Your provider will examine you. The inflammation causes a breakdown of muscle cells, so you may have a blood test (CPK or Aldolase level) to look for abnormal amounts of broken cells. Other types of tests might include:
- biopsy of the involved area (the removal of a small sample of muscle after an anesthetic) to check for inflammation
- electromyography, or EMG, a test that looks at muscle strength and function.
- Sedimentation Rate (ESR) or C-Reactive Protein Level (CRP)
Is there any treatment?
Treatment for polymyositis generally consists of a steroid drug called prednisone. For patients in whom prednisone is not effective, immunosuppressants such as azathioprine and methotrexate may be prescribed. Intravenous immunoglobulin has also helped difficult cases. Physical therapy is usually recommended to avoid muscle atrophy.
What is the prognosis?
The prognosis for polymyositis varies. Response to therapy varies from very good to satisfactory. Some patients have a more severe disease that does not respond adequately to therapies and are left with significant disability. Death is rare but may occur in patients with severe and progressive muscle weakness, dysphagia, malnutrition, pneumonia, or respiratory failure.
Other Resources:
American Autoimmune Related Diseases Association
22100 Gratiot Avenue
Eastpointe
East Detroit, MI 48201-2227
aarda@aarda.org
http://www.aarda.org
Tel: 586-776-3900 800-598-4668
Fax: 586-776-3903
National Organization for Rare Disorders (NORD)
P.O. Box 1968
(55 Kenosia Avenue)
Danbury, CT 06813-1968
orphan@rarediseases.org
http://www.rarediseases.org
Tel: 203-744-0100 Voice Mail 800-999-NORD (6673)
Fax: 203-798-2291
Muscular Dystrophy Association
3300 East Sunrise Drive
Tucson, AZ 85718-3208
mda@mdausa.org
http://www.mdausa.org
Tel: 520-529-2000 800-572-1717
Fax: 520-529-5300
