(Idiopathic Inflammatory Myopathy)
Dermatomyositis is a non-infectious inflammation of muscle tissue and skin.
Dermatomyositis and its sister disease, polymyositis, belong to a large category of connective tissue disorders that includes lupus erythematosus, rheumatoid arthritis, and scleroderma (systemic sclerosis). They are all believed to represent “autoimmune disorders” wherein the body launches an attack against its own tissues. They are all chronic, progressive conditions that lead to tissue destruction. They are potentially serious conditions that require care from your doctor. The sooner they are treated, the more favorable the outcome. If you suspect you have dermatomyositis, contact your doctor immediately.
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 misidentify infected skin and muscle tissue as a threat.
The following factors increase your chances of developing dermatomyositis:
- Another connective tissue disorder
If you experience 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 experience any one of them, see your physician.
- Weakness, especially of the hips and thighs, making it difficult to negotiate stairs and stand up, but also arms or neck
- Aching leg (arm or neck) pain
- Tender muscles
- Difficulty swallowing
- Red (or heliotrope), bumpy, or scaling skin rash
- Puffiness around the eyes
- Aching and color changes (red, white, and blue) in fingers, especially in cold temperatures
- Joint pains
Your doctor will ask about your symptoms and medical history, and perform a physical exam. You are likely to be referred to a rheumatologist.
Tests may include the following:
- Blood tests
- Electromyogram (EMG) - to test the electrical responsiveness of your muscles. This test involves inserting tiny needles into affected muscles and stimulating them with minute electrical currents.
- Muscle biopsy – surgical removal of a small piece of muscle to examine it under a microscope.
- A search for cancer, since in adults dermatomyositis is associated with a cancer about 15% of the time and may be the first sign of the cancer.
Talk with your doctor about the best treatment plan for you. Treatment options include the following:
General health maintenance
Because dermatomyositis is a serious disease with long-term implications, physical exercise, a healthy lifestyle, and a nutritious diet are an integral part of the treatment.
Cortisone-like drugs, usually oral prednisone, often produce a satisfactory response over the course of 2–3 months, after which the dose is reduced according to the activity of the disease.
Agents used to treat cancer and organ transplants such as methotrexate, cyclophosphamide, chlorambucil, azathioprine, and cyclosporine have improved patients who did not respond to prednisone.
Intravenous immune globulin, total body irradiation, plasma exchange and leukapheresis have been used for severe disease.
There are no known ways to prevent dermatomyositis.