Definition
Drug-induced lupus erythematosus is an inflammatory autoimmune disorder that may affect many organ systems. It is caused from an adverse reaction to a medication.

Causes, incidence, and risk factors

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.

Symptoms

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

Signs and tests
The history shows use of a medication associated with drug-induced lupus. An examination of the skin shows characteristic skin rash or lesions. Signs of pericarditis may be present. Listening to the chest with a stethoscope (auscultation) may reveal abnormal sounds such as heart murmur, pleural friction rub, or pericardial friction rub.

Tests for SLE include:

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

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

Treatment

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.

Expectations (prognosis)
Symptoms usually resolve within several days to weeks after stopping the medication. It is essential not to restart the culprit medication at a later time, as symptoms will usually recur.

Complications

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

Calling your health care provider
Call for an appointment with your health care provider if symptoms do not improve after the medication that caused the symptoms has been discontinued, or new symptoms develop.

Prevention
Be aware of the risk when taking medications that are known to cause this reaction. If symptoms begin to appear, consult your health care provider about the advisability of changing medication.

Medical Encyclopedia

All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.