What is Polymyositis
Polymyositis
is an inflammatory muscle disease that causes varying
degrees of decreased muscle power. 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
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