POLYMYOSITIS & DERMATOMYOSITIS

General Information

DEFINITION--Inflammation of connective tissue, with degenerative changes in the muscles (polymyositis) and skin (dermatomyositis). This causes weakness and muscle wasting, especially in the arms and legs. This disease has many similarities to rheumatoid arthritis and lupus erythematosus.

BODY PARTS INVOLVED--Muscles, including large muscles of the skeleton and tiny muscles that control small arteries; skin; connective tissue.

SEX OR AGE MOST AFFECTED

• Twice as common in women as men.
• All ages, but most likely to begin between ages 30 and 50.

SIGNS & SYMPTOMS--

Sudden or slow onset of the following:

• Weakness in the pelvic-girdle and shoulder-girdle muscles.
• Skin rash that may itch on the face, shoulders, arms and over joints.
• Cold hands and feet.
• Frequent falls and difficulty in getting up.
• Speaking or swallowing difficulty.
• Infection with fever, muscle weakness, weight loss and joint pain (sometimes) preceding other symptoms.

CAUSES--Probably a disease of hypersensitivity or autoimmunity, although the cause is uncertain. This disease has been associated with the use of certain drugs and preceding bacterial infections, viral infections and vaccines.

RISK INCREASES WITH

• Allergies.
• Use of sulfa drugs, penicillin, antithyroid drugs, gold and thiazide diuretics.
• Family history of hypersensitivity diseases.
• Cancer of the lung, colon or breast.

HOW TO PREVENT--No specific preventive measures.

What To Expect

DIAGNOSTIC MEASURES--

• Medical history and exam by a doctor.
• Laboratory studies to measure antinuclear antibodies (ANA) and muscle enzymes.
• Surgical diagnostic procedures, such as biopsy of muscle and electromyography (See Glossary for both).

APPROPRIATE HEALTH CARE

• Doctor's treatment.
• Hospitalization during early, active phases.
• Surgery, if intestinal obstruction occurs.
• Physical therapy and rehabilitation.

POSSIBLE COMPLICATIONS

• Muscle and body wasting; congestive heart failure; high blood pressure.
• Intestinal obstruction.
• Kidney damage.
• Pneumonia; respiratory problems.
• Cancer.

PROBABLE OUTCOME--The disease may begin suddenly or gradually. Muscle weakness may be severe and progressive. Some symptoms can be controlled with treatment. Patients with cardiac or pulmonary involvement tend to have more severe symptoms that are somewhat resistant to treatment. Remissions or spontaneous recovery can occur--especially in children. Research into causes and treatment continues, so there is hope for increasingly effective treatment and cure.

How To Treat

GENERAL MEASURES--

• Care can usually be managed at home. In time, a wheelchair may be required or confinement to bed due to the muscle weakness.
• Passive exercise should be provided to prevent contractures (muscle shortening).
• Cool-water compresses may relieve itching.
• See Muscular Dystrophy in Resources for Additional Information.

MEDICATION--Your doctor may prescribe:

• Cortisone drugs in high doses until acute symptoms diminish, then in lower doses.
• Cytotoxic or immunosuppressive drugs, if other treatment is not effective.
• Medications to help control itching.
• Pain medications if needed.

ACTIVITY--

• Restrict activities during acute phase. Bed rest is recommended. Pace activities to counteract muscle weakness.
• If confined to bed, the patient should be moved frequently to prevent pressure sores.

DIET--No special diet. Salt restriction diet might prevent fluid retention. Ask your doctor.

Call Your Doctor If

The following occurs during treatment: Blood in the urine. Shortness of breath. Chest pain. Bloody bowel movements. Severe abdominal pain. Fever.