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- Exercises to Relieve Arthritis Pain
- Quiz: What Causes RA?
- Patient Comments: Polymyositis - Effective Treatments
- Patient Comments: Polymyositis - Symptoms and Signs
- Patient Comments: Polymyositis - Personal Experience
- Find a local Rheumatologist in your town
- Polymyositis and dermatomyositis facts
- What is polymyositis? What is dermatomyositis?
- Polymyositis vs. polymyalgia rheumatica
- What causes polymyositis and dermatomyositis?
- What are signs and symptoms of polymyositis and dermatomyositis?
- What tests do doctors use to diagnose polymyositis or dermatomyositis?
- What types of doctors treat polymyositis and dermatomyositis?
- What is the treatment for polymyositis and dermatomyositis?
- What are home remedies for polymyositis and dermatomyositis?
- What is the prognosis for polymyositis?
- What are risk factors for worse outcomes with polymyositis or dermatomyositis?
- Is it possible to prevent polymyositis?
- Are there support groups for people with polymyositis and dermatomyositis?
- Where can people find more information on polymyositis and dermatomyositis?
Polymyositis vs. polymyalgia rheumatica
Polymyositis is an inflammatory, destructive, autoimmune muscle disease, usually with weakness but unusually with pain. Polymyalgia rheumatica is an inflammatory disease of muscle that always causes symmetrically painful muscles. Polymyalgia rheumatica is not destructive to muscles.
What causes polymyositis and dermatomyositis?
To date, no cause of polymyositis has been isolated by scientific researchers. There are indicators of heredity (genetic) susceptibility that can be found in some patients. There is indirect evidence of infection by a virus that has yet to be identified in a muscle disease related to polymyositis that is particularly resistant to treatment, called inclusion body myositis. The pathologist, a physician specialist who interprets the microscope findings of muscle tissue, diagnoses this muscle disease. The muscle tissue in inclusion body myositis displays clear areas within the muscle cells (called vacuoles) when viewed under the magnification of a microscope.
Researchers have found that T-cells of the immune system in some polymyositis or dermatomyositis patients reacted against cytomegalovirus (CMV) and that detectable antibodies against CMV were present. Their conclusion was that there may be subsets of patients who develop their disease, in part, because of infection with this particular virus.
Aside from diseases with which polymyositis can be associated (as mentioned above), many other diseases and conditions can mimic polymyositis. These include nerve-muscle diseases (such as muscular dystrophies), drug toxins (such as alcohol, cocaine, steroids, colchicine, hydroxychloroquine, and cholesterol-lowering drugs, called statins), metabolic disorders (where muscle cells are unable to process chemicals normally), hormone disorders (such as abnormal thyroid), inclusion body myositis, calcium and magnesium conditions, and infectious diseases (such as influenza virus, AIDS, streptococcus and Lyme bacteria, pork tapeworm, and schistosomiasis).