Drug-induced lupus erythematosus is an autoimmune disorder that is brought on by a reaction to medication.

See also: Systemic lupus erythematosus (SLE)

Drug-induced lupus erythematosus resembles systemic lupus erythematosus (SLE). It results from a hypersensitivity reaction to a medication. The drug may react with cell materials, causing the body to form antibodies that attack the body's own healthy cells.

Several medications are known to cause drug-induced lupus. They include:

• Chlorpromazine
• Hydralazine
• Isoniazid
• Methyldopa
• Penicillamine
• Procainamide
• Quinidine
• Sulfasalazine

Symptoms tend to occur after taking the drug for at least 3 to 6 months.

Persons with drug-induced lupus erythematosus may have symptoms that affect the joints (arthritis), heart, and lungs. Other symptoms associated with SLE, such as lupus nephritis and neurological disease, are rare.

Drug-induced lupus affects men and women equally.

• Blurred vision
• Fever
• General ill feeling (malaise)
• Joint pain
• Joint swelling
• Loss of appetite
• Pleuritic chest pain
• Skin rash
  • Gets worse with sunlight
  • "Butterfly" rash across bridge of nose and cheeks
• Weight loss

The doctor will listen to your chest with a stethoscope. A sound called a heart friction rub or pleural friction rub may be heard. Signs of pericarditis may be present.

A skin exam shows a characteristic skin rash.

The patient will have taken a medicine linked to drug-induced lupus.

Tests that may be done include:

• Antihistone antibody (often positive in drug-induced lupus)
• Antinuclear antibody (ANA) panel
• Lupus erythematosus cell test (rarely used)

A chest x-ray may show signs of pleuritis or pericarditis. An ECG may show heart involvement.