What is Polymyositis?
Polymyositis is one of a group of muscle diseases known as the inflammatory
myopathies, which are characterized by chronic muscle inflammation accompanied
by muscle weakness. Polymyositis affects skeletal muscles (those involved with
making movement) on both sides of the body. It is rarely seen in persons under
age 18; most cases are in adults between the ages of 31 and 60. Slow, but
progressive muscle weakness starts in the proximal muscles (muscles closest to
the trunk of the body) which eventually leads to difficulties climbing stairs,
rising from a sitting position, lifting objects, or reaching overhead. People
with polymyositis may also experience arthritis, shortness of breath, difficulty
swallowing and speaking, and heart arrhythmias. In some cases of polymyositis,
distal muscles (muscles further away from the trunk of the body, such as those
in the forearms and around the ankles and wrists) may be affected as the disease
progresses. Polymyositis may be associated with collagen-vascular or autoimmune
diseases, such as lupus. Polymyositis may also be associated with infectious
disorders, such as HIV-AIDS.
Is there any treatment?
There is no cure for polymyositis, but the symptoms can be treated. Options
include medication, physical therapy, exercise, heat therapy (including
microwave and ultrasound), orthotics and assistive devices, and rest. The
standard treatment for polymyositis is a corticosteroid drug, given either in
pill form or intravenously. Immunosuppressant drugs, such as azathioprine and
methotrexate, may reduce inflammation in people who do not respond well to
prednisone. Periodic treatment using intravenous immunoglobulin can also improve
recovery. Other immunosuppressive agents used to treat the inflammation
associated with polymyositis include cyclosporine A, cyclophosphamide, and
tacrolimus. Physical therapy is usually recommended to prevent muscle atrophy
and to regain muscle strength and range of motion.
What is the prognosis?
The prognosis for polymyositis varies. Most people respond fairly well to
therapy, but some have a more severe disease that does not respond adequately to
therapies and are left with significant disability. In rare cases individuals
with severe and progressive muscle weakness will develop respiratory failure or
pneumonia. Difficulty swallowing may cause weight loss and malnutrition.
What research is being done?
The National Institute of Neurological Disorders and Stroke (NINDS) and other
institutes of the National Institutes of Health (NIH) conduct research relating
to polymyositis in laboratories at the NIH and support additional research
through grants to major medical institutions across the country. Currently
funded research is exploring patterns of gene expression among the inflammatory
myopathies, the role of viral infection as a precursor to the disorders, and the
safety and efficacy of various treatment regimens.
Organizations
American Autoimmune Related Diseases Association
22100 Gratiot Avenue
Eastpointe, MI 48201-2227
aarda@aarda.org
www.aarda.org
Tel: 586.776.3900 800.598.4668
Fax: 586.776.3903
Muscular Dystrophy Association
3300 East Sunrise Drive
Tucson, AZ 85718-3208
mda@mdausa.org
www.mda.org
Tel: 520.529.2000 800.344.4863
Fax: 520.529.5300
Myositis Association
1233 20th Street, NW, Suite 402
Washington, DC 20036
tma@myositis.org
www.myositis.org
Tel: 202.887.0088 800.821.7356
Fax: 202.466.8940
National Organization for Rare Disorders (NORD)
P.O. Box 1968
(55 Kenosia Avenue)
Danbury, CT 06813-1968
orphan@rarediseases.org
www.rarediseases.org
Tel: 203.744.0100 Voice Mail 800.999.NORD (6673)
Fax: 203.798.2291
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
National Institutes of Health, DHHS
31 Center Dr., Rm. 4C02 MSC 2350
Bethesda, MD 20892-2350
NIAMSinfo@mail.nih.gov
www.niams.nih.gov
Tel: 301.496.8190 877.22.NIAMS (226.4267)
Source: National Institutes of Health; National Institute of Neurological Disorders and Stroke
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 1/29/2009...#6100
