• Rare Muscle and Skin Disorder Can Be Difficult to Treat

Rare Muscle and Skin Disorder Can Be Difficult to Treat

November 26, 2010

Dear Mayo Clinic:

My ten-year-old daughter has been diagnosed with dermatomyositis. What are her treatment options? Are there things we can do (nutrition, lifestyle) that will help her?

Answer:

Dermatomyositis is one in a group of muscle disorders known as inflammatory myopathies. What causes these disorders is not clear, although some research suggests that genetics may play a role. Inflammatory myopathies are autoimmune diseases. Instead of your immune system protecting your body from bacteria, viruses and other harmful intruders, in these diseases the immune system releases antibodies that attack your own healthy tissue. Dermatomyositis is the most common inflammatory myopathy to affect children, particularly between the ages of 5 and 15.

Children affected by dermatomyositis often develop red or bluish-purple skin rashes on the face, eyelids, knuckles, elbows and knees. A common symptom of dermatomyositis is muscle weakness that affects both sides of the body equally and seems to get worse over time. Other symptoms may include fatigue, muscle pain and difficulty swallowing.

Prompt diagnosis and treatment are key to effectively managing the symptoms of dermatomyositis and avoiding serious complications, such as the development of hardened deposits of calcium under the skin (calcinosis).

Likely, the first step in your daughter's treatment will be high doses of a corticosteroid medication, such as prednisone, to get her symptoms under control. Corticosteroids suppress the body's immune system. This decreases the amount of inflammation the immune system produces, leading to reduced skin and muscle damage and increased muscle strength and function. High-dose corticosteroids alone aren't a long-term solution, though, because they can cause significant side effects, including cataracts and glaucoma, high blood pressure, high blood sugar and loss of bone calcium.

To reduce the risk of these side effects, your daughter's doctor may decrease the corticosteroid dose after several weeks and combine it with other drugs known as steroid-sparing agents. These medications, such as methotrexate, cyclosporin or azathioprine, can help decrease corticosteroid side effects.

Children who have severe forms of the disease may benefit from intravenous immunoglobulin (IVIG), a therapy that uses healthy antibodies from blood donors to block the effects of dermatomyositis. Calcium and vitamin D supplements can also be useful for improving bone density in children with dermatomyositis.

In addition to medications, exercise can be particularly helpful for increasing muscle strength and endurance in children who have this disease. If you haven't already done so, talk to your daughter's doctor about creating an exercise program she can follow. Because fatigue can be a problem, encourage your daughter to rest when she begins to feel tired, rather than continuing until she is exhausted. Some children may have a difficult time recognizing when they are becoming fatigued. Keeping a regular, healthy sleep schedule can help. Finally, your daughter should cover up with protective clothing or wear sunscreen regularly when she's outside, as areas of skin affected by the dermatomyositis rash are particularly sensitive to the sun.

Although the symptoms of dermatomyositis may come and go, this is typically a chronic condition that requires long-term management. Fortunately, with early treatment and consistent, ongoing care, the physical and social outlook for most children with dermatomyositis is excellent.

— Ann Reed, M.D., Pediatric Rheumatology, Mayo Clinic, Rochester, Minn.