Treatment of Drug-Induced Leukocytoclastic Vasculitis
The primary treatment for drug-induced leukocytoclastic vasculitis is immediate discontinuation of the offending medication, which alone is often sufficient to induce prompt resolution without requiring immunosuppressive therapy. 1, 2
Initial Management: Drug Withdrawal
- Discontinue the causative drug immediately upon clinical suspicion, as this is critical to control the vasculitis and prevent relapses 1, 2
- Drug withdrawal alone typically leads to resolution of clinical manifestations within days to weeks, obviating the need for aggressive immunosuppressive treatment in most cases 2
- Common culprit medications include hydralazine, propylthiouracil, levamisole-adulterated cocaine, minocycline, levetiracetam, and warfarin 1, 3, 4
Diagnostic Clues for Drug-Induced Vasculitis
Before initiating immunosuppression, look for these distinguishing features that suggest drug-induced rather than idiopathic vasculitis 1:
- High-titre MPO ANCA positivity or dual MPO and PR3 ANCA positivity
- Discordance between ANCA type by immunofluorescence versus ELISA
- Positive ANA and antihistone antibodies
- In levamisole-induced cases: neutropenia and retiform purpuric rash
- Temporal relationship: onset within days to weeks of drug initiation 3
When to Add Corticosteroids
Systemic corticosteroids should be added only when there are signs of incipient skin necrosis or severe systemic involvement 5:
- Use corticosteroids (prednisolone 1 mg/kg/day, max 60 mg/day) for impending skin necrosis 1, 5
- Most cases of isolated cutaneous leukocytoclastic vasculitis do not require aggressive immunosuppressive therapy due to favorable prognosis 5
- Avoid treatment altogether for very mild, isolated skin vasculitis 6
Supportive Measures
- Compression stockings to reduce purpura in gravity-dependent areas 5
- Treat any underlying infection if present (throat swabs, blood cultures) 5
- Monitor for systemic involvement: urinalysis for renal involvement, complete blood count 5
Chronic or Relapsing Cases (Rare in Drug-Induced)
If vasculitis persists despite drug withdrawal or becomes chronic 5:
- First-line: Colchicine
- Second-line: Dapsone
- Reserve immunosuppressive strategies only for severe systemic vasculitis with organ involvement
Critical Pitfall to Avoid
Do not confuse drug-induced leukocytoclastic vasculitis with ANCA-associated vasculitis (AAV) requiring cyclophosphamide or rituximab 1. The EULAR/KDIGO guidelines for AAV treatment with cyclophosphamide, rituximab, and plasma exchange apply to idiopathic GPA/MPA, not drug-induced vasculitis 1. Drug-induced cases resolve with drug discontinuation and do not require the aggressive immunosuppression protocols used for primary systemic vasculitis 2.