WHAT IS POLYMYOSITIS?
Polymyositis is an inflammation of the muscle tissue that leads to weakness. It occurs in approximately 1 person per 100,000, mostly in people over the age of 20. Women are affected about twice as often as men and all ethnic groups are affected.

WHAT ARE THE SYMPTOMS?
Patients with polymyositis develop weakness in the large muscles around the neck, shoulders and hips. This causes difficulty in climbing stairs, getting up from a chair or toilet seat, or reaching for objects overhead. Most patients have little if any pain in their muscles, which distinguishes them from patients with other forms of muscle disease, from those who have joint pain due to arthritis, and from those with numbness or tingling in their hands and feet due to neurological problems.

Some patients with polymyositis develop weakness of throat muscles involved in swallowing, and this may cause choking or aspiration (intake) of food into the lungs when eating. Others may experience shortness of breath and cough due to inflammation of the lungs.

HOW IS IT DIAGNOSED?
A diagnosis of polymyositis is suspected when patients complain of difficulty performing tasks that require muscle strength or when they develop certain rashes or respiratory problems. To establish a diagnosis, a muscle strength examination will be performed to determine if true muscle weakness is present. This likely will be followed by a blood test to measure the level of various muscle enzymes like CPK, an electromyogram to gauge electrical activity in muscle, and finally a biopsy of a weak muscle. Sometimes MRI scanning can help to establish the presence of abnormal muscle. Blood may also be tested for the presence of myositis-specific antibodies (immune proteins), which help to establish a diagnosis and give some information about prognosis.

HOW IS IT TREATED?
There are several treatment options for polymyositis patients. An oral corticosteroid such as prednisone (Deltasone and others) is usually administered in high doses once the diagnosis has been established. Blood muscle enzymes usually return to normal in about 4 to 6 weeks and patients gradually regain strength in 2 to 3 months. Methotrexate or azathioprine are usually added to ensure better long term control of the disease and to avoid long term side effects of cortisone such as weight gain and redistribution of body fat, thinning of the skin, osteoporosis, cataracts and even muscle weakness. In severe or treatment-resistant cases additional measures may include intravenous immunoglobulin (IVIG) and other immunosuppressive medications including cyclosporine (Neoral, Sandimmune), tacrolimus (Prograf) or mycophenolate (Cellcept).

Physical therapy and exercise are important in the treatment of myopathy. Severely weak patients who are confined to their beds should receive range of motion exercises to prevent joint contractures (distortion or deformity of the joint). Patients with moderate weakness should begin a muscle-strengthening program that gradually increases in intensity as strength is regained. Patients with swallowing difficulties should receive appropriately prepared food and should be positioned in bed to prevent choking. Patients being treated with prednisone are at risk for the development of osteoporosis and should receive appropriate preventive treatment.

WHAT IS THE PROGNOSIS?
Just as the disease itself varies, so does the prognosis for polymyositis. Some patients have a more severe disease that does not respond adequately to therapies and are left with significant disability. Many patients are able to find relief from many of their symptoms through one or more of the therapies described above.

SUPPORT GROUPS
Crescent Healthcare is proud to support the efforts of patient groups like the Myositis Association On their website you will find more information about polymyositis and the local support chapters.