Drug-Induced Lupus

Key points

• In drug-induced lupus, not all the typical features of SLE are seen — renal and nervous system involvement are unusual, and it usually resolves on stopping the causative drug
• Skin (e.g. malar rash) and pulmonary involvement (e.g. pleurisy) are common
• ANA positive in almost 100% of cases; anti-dsDNA is usually negative
• Anti-histone antibodies are found in 80–90% of cases
• Anti-Ro and anti-Smith are positive in only around 5%
• Most common causes: procainamide, hydralazine; less common causes include isoniazid, minocycline, phenytoin