Drug-induced lupus
Drug-induced lupus is a milder, reversible lupus-like syndrome triggered by an offending medication, marked by transient antinuclear and antihistone antibodies with sparing of the kidney and central nervous system. Management is stopping the culprit drug, with an NSAID or a short low-dose glucocorticoid course for residual arthritis, fever, or serositis.
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What this article covers
- Overview
Definition: drug-induced lupus is a lupus-like syndrome triggered by a specific medication that mimics systemic lupus erythematosus (SLE) clinically and serologically, and resolves after the offending drug is withdrawn.
- Epidemiology
Equal sex distribution: unlike idiopathic SLE, which is strongly female-predominant, drug-induced lupus affects men and women in roughly equal numbers, clustering in an older population.
- Risk factors
Cumulative exposure to a culprit drug: procainamide and hydralazine are the classic, highest-risk agents; longer and higher exposure raises risk.
- Pathophysiology
Reactive metabolite formation: procainamide, hydralazine, and related culprit drugs are metabolized by acetylation and oxidative pathways that generate reactive intermediates.
- Clinical features
Constitutional symptoms: fever and malaise are common and often prompt the initial evaluation.
- Differential diagnosis
Systemic lupus erythematosus: shares fever, arthritis, rash, and a positive ANA, but SLE is female-predominant, commonly involves the kidney and central nervous system, and shows hypocomplementemia…
- Diagnosis
First, establish the temporal relationship: onset of typical symptoms after starting a culprit drug, most often 3 weeks to 2 years into therapy, plus rapid clinical improvement after stopping it…
- Management
First, stop the offending drug. This single step is the definitive treatment; most patients improve within days and reach substantial clinical resolution within about 6 weeks, though a positive ANA…
- Complications
Serositis-related complications: pericarditis occurs in around 20% of patients and rarely progresses to a clinically significant effusion requiring evaluation.
- Prognosis
Overall prognosis is good: the large majority of patients improve substantially and most symptoms resolve after the offending drug is stopped.
- Prevention
Avoid reintroducing the culprit drug or a related agent in the same class once a patient has had drug-induced lupus from it.
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