Dermatomyositis

What is Dermatomyositis?

Dermatomyositis is one of a group of acquired muscle diseases called inflammatory myopathies. The disease, which has a subacute (somewhat short and relatively severe) onset, affects both children and adults. Females are more often affected than males. Dermatomyositis is characterized by a rash accompanying, or more often, preceding muscle weakness. The rash is described as patchy, bluish-purple discolorations on the face, neck, shoulders, upper chest, elbows, knees, knuckles, and back. Some patients may also develop hardened bumps of calcium deposits under the skin. The most common symptom is muscle weakness, usually affecting those muscles that are closest to the trunk of the body (proximal). Eventually, patients have difficulty rising from a sitting position, climbing stairs, lifting objects, or reaching overhead. In some cases, distal muscles (those not close to the trunk of the body) may be affected later in the course of the disease. Trouble with swallowing (dysphagia) may occur. Occasionally, the muscles ache and are tender to touch. Patients may also feel fatigue and discomfort and have weight loss or a low-grade fever.

Is there any treatment?

Treatment for dermatomyositis generally consists of a steroid drug called prednisone. For patients in whom prednisone is not effective, other immunosuppressants such as azathioprine and methotrexate may be prescribed. Recently, a drug called intravenous immunoglobulin was shown to be effective and safe in the treatment of the disease. Physical therapy is usually recommended to preserve muscle function and avoid muscle atrophy.

What is the prognosis?

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

What research is being done?

The NINDS conducts and supports a broad range of research on neuromuscular disorders such as inflammatory myopathies. The goals of these studies are to conduct therapeutic trials to increase understanding of the disorders and, ultimately, to find ways to prevent and cure them.