(Idiopathic Inflammatory Myopathy)
Dermatomyositis is a noninfectious inflammation of muscle tissue and skin.
Dermatomyositis and its sister disease, polymyositis]]>, belong to a large group of connective tissue disorders that includes ]]>lupus erythematosus]]>, ]]>rheumatoid arthritis]]>, and ]]>scleroderma]]> (systemic sclerosis).
They are all believed to be “autoimmune disorders,” where the body launches an attack against its own tissue. These chronic, progressive conditions lead to tissue damage. They can be serious conditions that require care from your doctor. The sooner these disorders are treated, the better the outcome. If you suspect you have this condition, contact your doctor right away.
Although the cause or causes are not known, a viral infection may trigger the onset of dermatomyositis by causing the body’s immune system to identify infected skin and muscle tissue as a threat.
Your chance of developing this condition is higher if you have another connective tissue disorder.
If you have any of these symptoms, do not assume it is due to dermatomyositis. These symptoms may be caused by other, less serious health conditions. If you have any one of the following symptoms, see your doctor.
- Especially of the hips and thighs (making it difficult to climb stairs or stand)
- May also occur in arms or neck
- Aching pain in legs, shoulder, arm, or neck
- Tender muscles
- Difficulty swallowing
- Violet-colored, bumpy, or scaly skin rash (especially around the eyes, upper back, elbows, or knuckles)
- Itching, especially the scalp
- Photosensitivity (skin burning or itching upon exposure to sunlight)
- Aching and color changes (red, white, and blue) in fingers, especially in cold temperatures
- Joint pain
- Shortness of breath
Your doctor will ask about your symptoms and medical history and perform a physical exam. You are likely to be referred to a rheumatologist (a doctor who specializes in musculoskeletal disorders).
Tests may include the following:
- Blood tests
- Electromyogram (EMG)]]>—This is to test the electrical responsiveness of your muscles. This test involves putting tiny needles into affected muscles and stimulating them with tiny electrical currents.
- Muscle ]]>biopsy]]>—This is a surgical removal of a small piece of muscle to examine it under a microscope.
- ]]>Magnetic resonance imaging (MRI)]]> or ultrasound—This helps to detect inflammation in your muscles.
- Skin biopsy—This is the surgical removal of a small piece of skin to examine it under a microscope.
- Cancer tests—In adults, this condition is associated with cancer about 15% of the time. It may be the first sign of cancer.
- ]]>CAT scan (CT)]]>—This is a type of x-ray that uses a computer to make pictures of structures inside of the body, in this case the chest (Dermatomyositis may be associated with lung disease.).
Talk with your doctor about the best treatment plan for you. Treatment options include the following:
General Health Maintenance
Because this is a serious disease with long-term implications, physical exercise, a healthy lifestyle, and a nutritious diet are an integral part of treatment.
Cortisone-like drugs, usually oral prednisone, often produce a satisfactory response over the course of 2-3 months. After this, the dose may be reduced according to the activity of the disease.
Agents used to treat cancer and organ transplants have helped patients who did not respond to prednisone. Examples of these medicines include:
American Academy of Family Physicians
Muscular Dystrophy Association
The Myositis Association
National Institute of Neurological Disorders and Stroke
The Arthritis Society
Muscular Dystrophy Canada
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Bolognia JL, Jorizzo J, Rapini RP. Dermatology. London: Elsevier Science; 2003.
Chung L, Genovese MC, Fiorentino DF. A pilot trial of rituximab in the treatment of patients with dermatomyositis. Arch Dermatol. 2007;143:763-767.
Dalakas MC. Polymyositis, dermatomyositis, and inclusion body myositis. In: Kasper DL, et al, eds. Harrison's Principles of Internal Medicine. 16th ed. New York: McGraw-Hill; 2005: 2540-2545.
Dermatomyositis. EBSCO Dynamed website. Available at: http://www.ebscohost.com/dynamed/what.php. Accessed August 2005.
Dold S, Justiniano ME, Marquez J, Espinoza LR. Treatment of early and refractory dermatomyositis with infliximab: a report of two cases. Clin Rheumatol. 2007;26:1186-1188.
Wong EH, Hui AC, Griffith JF, et al. MRI in biopsy-negative dermatomyositis. Neurology. 2005;64:750.
Last reviewed November 2009 by ]]>Jill D. Landis, MD]]>
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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