Drug-induced Lupus Erythematosus

Drug-induced Lupus Erythematosus (DILE) is a form of lupus erythematosus that is caused by the chronic use of certain prescription drugs. Unlike systemic lupus erythematosus (SLE), which is an autoimmune disease occurring without known cause, DILE has a direct link to medication use. The symptoms of DILE are similar to those of SLE, including skin rash, joint pain, and fever, but typically resolve after the offending drug is discontinued.

Causes

DILE is associated with several classes of drugs, most notably antihypertensives, antibiotics, and antiarrhythmics. Common drugs that have been linked to DILE include hydralazine, procainamide, and isoniazid. The exact mechanism by which these drugs induce lupus is not fully understood, but it is believed to involve alterations in immune system function, leading to an autoimmune response.

Symptoms

The symptoms of DILE can vary but often mirror those of SLE. They include:

• Skin rash, particularly after exposure to sunlight
• Joint pain and swelling
• Fever
• Fatigue
• Pleurisy (pain in the chest on deep breathing)
• Pericarditis (inflammation of the outer lining of the heart)

Diagnosis

Diagnosis of DILE involves a combination of clinical evaluation, laboratory testing, and the exclusion of other potential causes of symptoms. Key tests include:

• Antinuclear antibody (ANA) test: Most DILE patients have a positive ANA test.
• Anti-histone antibodies: These are present in the majority of DILE cases and are less common in SLE.
• Complete blood count, liver function tests, and renal function tests to assess systemic involvement.

Treatment

The cornerstone of DILE treatment is the discontinuation of the offending drug. Symptoms usually resolve within days to months after stopping the drug. In cases where symptoms are severe, treatment may include:

• Nonsteroidal anti-inflammatory drugs (NSAIDs) for joint pain and stiffness
• Corticosteroids to reduce inflammation
• Antimalarial drugs such as hydroxychloroquine for skin and joint symptoms

Prevention

Prevention of DILE involves careful selection of medications in individuals at risk and monitoring for symptoms of lupus in patients who are started on known offending drugs. Regular follow-up and laboratory testing can help in early detection and management.

See Also

• Lupus erythematosus
• Systemic lupus erythematosus
• Drug reaction with eosinophilia and systemic symptoms (DRESS)
• Pharmacogenomics