Dermatomyositis

What is Dermatomyositis?

Dermatomyositis is one of a group of acquired muscle diseases called inflammatory myopathies. The disease, which has a somewhat severe onset, affects both children and adults. Females are more often affected than males. Dermatomyositis is characterised by a rash accompanying, or more often, preceding muscle weakness. The rash looks like patchy, bluish-purple discolorations on the face, neck, shoulders, upper chest, elbows, knees, knuckles, and back. Some people may also develop calcium deposits, which appear as hard bumps under the skin. The most common symptom is muscle weakness, usually affecting the muscles that are closest to the trunk of the body. Eventually, people have difficulty rising from a sitting position, climbing stairs, lifting objects, or reaching overhead. In some cases, muscles further away from the trunk of the body may be affected later in the course of the disease. Problems with swallowing (dysphagia) may occur. Occasionally, the muscles ache and are tender to the touch. Affected individuals may also feel fatigue and discomfort and experience weight loss or a low-grade fever.

Is there any treatment?

Prescribing a steroid drug, such as prednisone, is usually the first line of treatment. Immunosuppressants, such as azathioprine and methotrexate, may help those for whom prednisone is ineffective. Further treatment with intravenous immunoglobulin was shown to be effective and safe. Physical therapy is usually recommended to preserve muscle function and prevent muscle wasting.

What is the prognosis?

Most cases of dermatomyositis respond to therapy. The disease is usually more severe and resistant to therapy in individuals with cardiac or pulmonary problems.