...less medical jargon in a 'Quick Glance' format!
Dermatomyositisis an uncommon disease marked by muscle weakness and a distinctive skin rash. It's a type of inflammatory muscle disease which may occur at any age, but it mostly affects adults in their late 40s to early 60s or children between 5 and 15 years of age. Women have it more often than men do.
Periods of remission, when symptoms improve spontaneously, may occur. Treatments can improve your skin and your muscle strength and function.
The most common signs and symptoms of dermatomyositis include:
A violet-colored or dusky red rash, most commonly on your face, eyelids, and areas around your nails, knuckles, elbows, knees, chest and back. Affected areas are typically more sensitive to sun exposure.
Progressive muscle weakness, particularly in the muscles closest to the trunk, such as those in your hips, thighs, shoulders, upper arms and neck. This weakness is symmetrical, affecting both the left and right sides of your body.
Other dermatomyositis symptoms that may occur include:
Muscle pain or tenderness
Fatigue, fever and weight loss
Hardened deposits of calcium under the skin, especially in children
Gastrointestinal ulcers and infections, also more common in children
The skin rash usually occurs at the same time as muscle weakness, but may precede muscle weakness by a few weeks. Sometimes, the skin rash alone determines the diagnosis. In some children with dermatomyositis, the skin may become thick and hard in a way similar to scleroderma. When this happens, the condition is called sclerodermatomyositis.
Weakness in muscles, such as your hips and shoulders, can lead to difficulty in getting out of chairs, climbing stairs, brushing your hair or working with your arms over your head. Weakness in your neck muscles can make it hard to hold your head up.
This disease belongs to a group of conditions called inflammatory myopathies. Myopathies are diseases or abnormal conditions of the muscles. The cause of most inflammatory myopathies is unknown.
One of these diseases that's similar to dermatomyositis is polymyositis. Polymyositis leads to many of the same symptoms as dermatomyositis, but does not cause skin inflammation or a rash.
Some other inflammatory muscle diseases are: inclusion body myositis, which progresses more slowly than other forms; myositis associated with other connective tissue diseases, such as lupus or scleroderma; and myositis associated with cancer.
. . . Immune system plays role
Doctors suspect that inflammatory myopathies are autoimmune disorders, in which your immune system attacks normal body components. Infections caused by bacteria, parasites or viruses can cause inflammatory myopathies, but in most cases, doctors aren't able to identify a preceding infection. Some doctors think certain people may have a genetic susceptibility to the disease.
Typically, your immune system works to protect your healthy cells from attacks by foreign substances, such as bacteria and viruses. If you have this disease, an unknown cause seems to trigger your immune system to begin producing autoimmune antibodies that attack your body's own tissues.
Small blood vessels in muscular tissue appear to be particularly affected. Inflammatory cells surround the blood vessels and eventually lead to degeneration of muscle fibers. Many people show a detectable level of autoantibodies in their blood.
There's no cure for dermatomyositis, but treatment can improve your skin, muscle strength and function. Treatment begun early in the disease process tends to be more effective, often because there are fewer complications. Therapies include the following:
Corticosteroids These medications suppress your immune system, limiting the production of antibodies and reducing skin and muscle inflammation. Corticosteroids, especially prednisone, are usually the first choice in treating inflammatory myopathies.
Your doctor may start with a very high dose, and then decrease it as your signs and symptoms improve. Improvement generally takes about two to four weeks. Your doctor may also prescribe topical corticosteroids for your skin. Visible results are usually evident within three to six months, but therapy is often needed for years.
Prolonged use of corticosteroids can have serious side effects including osteoporosis, weight gain, diabetes, increased risk of some infections, mood swings, cataracts, high blood pressure, a redistribution of body fat and muscle weakness. As a result, your doctor may recommend supplements, such as calcium and vitamin D, and may prescribe bisphosphonates, such as alendronate (Fosamax) or risedronate (Actonel).
Immunosuppressants If your body doesn't respond adequately to corticosteroids, your doctor may recommend other immunosuppressive drugs, such as azathioprine (Imuran) or methotrexate (Rheumatrex). Your doctor may prescribe these alone or in combination with corticosteroids.
When in combination, these additional immunosuppressants can be used to lessen the dose and potential side effects of the corticosteroid. Immunosuppressants such as cyclophosphamide (Cytoxan) and cyclosporine (Neoral, Sandimmune) may improve signs and symptoms.
Antimalarial medications For a persistent rash, your doctor may prescribe an antimalarial medication, such as hydroxychloroquine (Plaquenil) or chloroquine phosphate (Aralen).
Physical therapy A physical therapist can show you exercises to maintain and improve your strength and flexibility and advise an appropriate level of activity. Your exercise program is likely to change during the course of the disease and treatment period. Keeping active in general and pacing yourself will help maintain muscle strength.
Surgery Surgery may be an option to remove painful calcium deposits.
Pain relievers Over-the-counter drugs such as aspirin, ibuprofen (Advil, Motrin, others) and acetaminophen (Tylenol, others), can be used to treat any accompanying pain. If these aren't sufficient, your doctor may prescribe a stronger pain reliever, such as codeine.
Dermatomyositis treatments that are still under investigation include:
Plasmapheresis This treatment, also called plasma exchange, is a type of blood cleansing in which damaging antibodies are removed from your blood.
Radiation therapy This involves irradiation of the lymph nodes to suppress your immune system.
Intravenous immunoglobulin This involves receiving intravenous infusions of antibodies from a group of donors over two to five days. This treatment is usually expensive. It may be an option for you if your condition is severe or resistant to other forms of therapy.
Fludarabine This agent prevents the development and growth of malignant cells.
Tacrolimus This transplant-rejection drug may work to inhibit the immune system. Tacrolimus is often used topically.
Monoclonal antibodies These man-made antibodies are designed to target and destroy specific types of cells. Clinical trials are studying the effects of infliximab (Remicade) and rituximab (Rituxan) on both polymyositis and dermatomyositis. Additionally, etanercept (Enbrel) is also being studied as a treatment option.