$Unique_ID{BRK04122} $Pretitle{} $Title{Polymyositis} $Subject{Polymyositis Primary Idiopathic Polymyositis Childhood Polymyositis Polymyositis malignant tumors Polymyositis connective tissue disease overlap syndromes Sclerodermatomyositis Mixed Connective Tissue disease} $Volume{} $Log{} Copyright (C) 1986, 1989, 1991, 1992 National Organization for Rare Disorders, Inc. 278: Polymyositis ** IMPORTANT ** It is possible the main title of the article (Polymyositis) is not the name you expected. Please check the SYNONYMS listing to find the alternate names and disorder subdivisions covered by this article. Synonyms DISORDER SUBDIVISIONS Primary Idiopathic Polymyositis Childhood Polymyositis Polymyositis associated with malignant tumors Polymyositis associated with connective tissue disease overlap syndromes, including Sclerodermatomyositis and Mixed Connective Tissue disease General Discussion ** REMINDER ** The information contained in the Rare Disease Database is provided for educational purposes only. It should not be used for diagnostic or treatment purposes. If you wish to obtain more information about this disorder, please contact your personal physician and/or the agencies listed in the "Resources" section of this report. Polymyositis is a systemic connective tissue disorder characterized by inflammatory and degenerative changes in the muscles, leading to symmetric weakness and some degree of muscle atrophy. The areas principally affected are the hip, shoulders, arms, pharynx and neck. Symptoms Symptoms of Polymyositis may start gradually or suddenly. The symptoms often wax and wane for no apparent reason. The major symptom of the disorder is muscle weakness, most often in the hip and shoulder areas, eventually making it difficult for patients to lift their arms or to climb steps. Other muscles which may be affected are the neck and throat muscles, which may result in difficulty in swallowing and cause changes in the voice. Rarely, chest muscles are affected. The muscle weakness may appear suddenly and progress over weeks to months. The difficulty in swallowing and dilatation of the lower esophagus and small intestine may be indistinguishable from that in Scleroderma (Progressive Systemic Sclerosis), (For more information on Scleroderma, choose "scleroderma" as your search term in the Rare Disease Database.) The muscles of the hands, feet and face often escape involvement. Contractures of the limbs may develop late in the chronic stage. Other symptoms of Polymyositis may include fever, weight loss and occasionally pain or tenderness in muscles and joints. A few people with Polymyositis have an extreme sensitivity to cold (Raynaud's Phenomenon) that is most often felt in the fingers. Raynaud's Phenomenon is caused by narrowing of the blood vessels in the fingers. (For more information, choose "Raynaud" as your search term in the Rare Disease Database.) People with Polymyositis may develop numb and shiny red areas around and under the finger nails. Pain in many joints (polyarthralgia), accompanied at times by swelling, fluid and other evidence of non-deforming arthritis, occurs in approximately one third of patients with polymyositis. These rheumatic complaints tend to be mild and respond well to corticosteroids. Gastrointestinal involvement, except for the pharynx and the esophagus, is relatively uncommon in polymyositis. Inflammation of the lungs with increase of interstitial tissue (interstitial pneumonitis), manifested by difficulty in breathing and by coughing, may precede myositis and dominate the clinical picture. Involvement of the heart, detected chiefly by irregularities in the electrocardiogram (ECG), has been reported. Acute kidney failure has been reported as a consequence of excess muscle protein myoglobin in the urine (Crush syndrome) due to severe disintegration of muscle (rhabdomyolysis). Sjogren's syndrome can occur in some patients with polymyositis. (For more information, choose "Sjogren" as your search term in the Rare Disease Database.) Abdominal symptoms, more common in children, may be associated with the passage of dark stools or the vomiting of blood from gastro-intestinal ulcerations that may progress to perforation and require surgical intervention. An associated malignancy, usually a carcinoma, may occur in about 15% of men and a smaller proportion of women over age 50 with polymyositis. Causes The cause of polymyositis is unknown. The disorders may be caused by the body's natural immune defense mechanisms attacking its own tissue (autoimmune reaction). Viruses may also play a role. Affected Population Polymyositis may appear at any time from infancy through the age of 80 years, but most commonly they occur between 40 to 60 years. In children, the symptoms usually appear between the ages of 5 to 15 years. Females are affected twice as often as males. Related Disorders Scleroderma (Progressive Systemic Sclerosis) is a rare, chronic collagen vascular disorder characterized by diffuse hardening, degenerative changes and vascular inflammation of the connective tissues of the skin, joints and many visceral organs. It shares certain clinical findings with polymyositis. Systemic Lupus Erythematosus (SLE) is an inflammatory connective tissue disorder that can affect many parts of the body including the joints, skin and internal organs. SLE is a disease of the body's immune system. It shares certain clinical findings with Polymyositis. (For more information on these related disorders, choose "Scleroderma" and "Lupus" as your search terms in the Rare Disease Database.) Therapies: Standard Corticosteroids such as prednisone, (together with antacids and potassium supplements), are widely used in treatment of Polymyositis. Measurement of muscle enzyme activity is used to gauge the effectiveness of therapy. Reduction of these enzymes to normal values is noted in a majority of patients with this disorder within 4 to 6 weeks after treatment is started. This is followed by an improvement in muscle strength. At this point the dose of prednisone can usually be reduced slowly. In many cases of adult polymyositis prolonged maintenance therapy with prednisone may be necessary indefinitely. Immunosuppressive drugs such as methotrexate, cyclophosphamide, chlorambucil and azathioprine have been beneficial to patients who fail to respond to corticosteroids alone. Some patients have received methotrexate for 5 years or longer for control of this disorder. Therapies: Investigational The FDA has approved the following orphan product for treatment of Polymyositis: Immune Globulin Intravenous (Human) (Iveegam, Immuno) Sponsored by: Immuno Clinic Research Corp. 155 E. 56th St. New York, NY 10022 The drug cyclophosphamide, in combination with the drug mesna, is being tested in severe polymyositis patients who are unresponsive to steroid immunosuppressant therapy. This therapy may be beneficial, but more research is needed to determine the long-term safety and effectiveness. This disease entry is based upon medical information available through November 1992. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder. Resources For more information on Polymyositis, please contact: National Organization for Rare Disorders (NORD) P.O. Box 8923 New Fairfield, CT 06812-1783 (203) 746-6518 Dermatomyositis and Polymyositis Support Group 146 Newtown Rd. Woolston, Southhampton SO2 9HR England Phone Southhampton 449708 The National Arthritis and Musculoskeletal and Skin Diseases Information Clearinghouse Box AMS Bethesda, MD 20892 (301) 495-4484 Arthritis Foundation 1314 Spring St., NW Atlanta, GA 30333 (404) 872-7100 References POLYMYOSITIS AND DERMATOMYOSITIS: C.M. Pearson; Arthritis Medical Information Series, Arthritis Foundation, 1983.