Several medications are known to cause a syndrome that resembles systemic lupus erythematosus (SLE) -- a chronic inflammatory autoimmune disorder that may affect many organ systems.

Drug-induced lupus erythematosus occurs as a result of a hypersensitivity reaction to a medication. The drug may react with cell materials, causing the body to react to itself and form antinuclear antibodies.

Drugs that are known to cause this type of reaction in some people include: procainamide, isoniazid, chlorpromazine, penicillamine, sulfasalazine, hydralazine, methyldopa, and quinidine. Symptoms tend to occur after taking the drug for a reasonable period of time, usually at least 3 to 6 months.

In drug-induced lupus erythematosus, the features of arthritis, systemic symptoms, and cardiac and pulmonary (lung) symptoms may be present. Other symptoms associated with SLE, such as lupus nephritis and neurological disease, are rare.

Drug-induced lupus erythematosus also differs from SLE in that the course of the disease is usually not as severe as SLE. Usually, the symptoms resolve within a few days to weeks after stopping the medication. The sex distribution of drug-induced lupus erythematosus is equal, whereas in SLE, women are affected more often than men.

• Fever
• Loss of appetite
• General discomfort, uneasiness, or ill feeling (malaise)
• Weight loss
• Skin rash
  • Malar "butterfly" rash
  • Skin rash aggravated by sunlight
• Joint pain
• Joint swelling
• Blurring vision
• Pleuritic chest pain

• Antinuclear antibody (ANA) panel
• Lupus erythematosus cell test (rarely performed nowadays)
• Anti-histone antibody (commonly positive in drug-induced lupus)

Usually, symptoms resolve within several days to weeks after stopping the medication that caused the symptoms. Nonsteroidal anti-inflammatory medications are used to treat arthritis and pleurisy.

Corticosteroid creams are used to treat skin rashes. Antimalarial drugs (hydroxychloroquine) are sometimes used for skin and arthritis symptoms. Sensitivity to light is treated by protective clothing, sunglasses, and sunscreen. Routine eye examinations are recommended to detect eye complications early.

Occasionally, the steroid prednisone is used to treat more severe cases, especially if the heart is involved. Very rarely, severe drug-induced lupus with severe cardiac involvement or significant kidney or neurologic disease requires high doses of steroids and strong medications that suppress the immune system, such as azathioprine or cyclophosphamide.

• Infection
• Thrombocytopenia purpura
• Hemolytic anemia
• Myocarditis
• Pericarditis