Treatment of Leukocytoclastic Small Vessel Vasculitis
Immediately discontinue any suspected offending medication, as this alone often induces prompt resolution without requiring immunosuppressive therapy. 1, 2
Initial Management: Drug Withdrawal First
The cornerstone of treatment is immediate discontinuation of the culprit drug upon clinical suspicion, which is critical to control the vasculitis and prevent relapses. 1, 2
Common offending medications include hydralazine, propylthiouracil, levamisole-adulterated cocaine, minocycline, levetiracetam, and warfarin. 1, 2
For drug-induced cases, discontinuation of the offending agent is usually sufficient and curative, with favorable prognosis. 3, 4
If an infectious organism is identified as the trigger, treating the infection will typically resolve the vasculitis. 3
When to Add Systemic Corticosteroids
Add systemic corticosteroids (prednisolone 1 mg/kg/day, maximum 60 mg/day) only when hemorrhagic blisters or signs of incipient skin necrosis appear. 1, 2
Do not routinely use corticosteroids for isolated cutaneous disease without these severe features. 1
For very mild forms of isolated skin vasculitis, the best option may be to avoid immunosuppressive treatment altogether. 3
Treatment for Chronic or Relapsing Disease
For patients with chronic or relapsing cutaneous leukocytoclastic vasculitis, use colchicine 0.6 mg twice daily as first-line treatment due to its effective and better safety profile than long-term corticosteroids. 1
- Low-dose corticosteroids may be used for symptom management in skin-limited disease, along with rest (avoiding prolonged standing or walking). 4
Critical Pitfall: Distinguishing Drug-Induced from ANCA-Associated Vasculitis
Do not treat drug-induced or isolated cutaneous leukocytoclastic vasculitis with cyclophosphamide or rituximab, as these aggressive immunosuppressants are reserved for true ANCA-associated systemic vasculitis and carry significant toxicity. 1, 2
Diagnostic Clues That Suggest Drug-Induced (Not Systemic AAV):
- High-titer MPO-ANCA or dual MPO/PR3 positivity 1, 2
- Discordance between ANCA immunofluorescence and ELISA results 1, 2
- Positive ANA and antihistone antibodies 1, 2
- Isolated cutaneous involvement without glomerulonephritis or pulmonary hemorrhage 1
- In levamisole-induced cases: neutropenia and retiform purpuric rash 2
When Systemic Vasculitis is Present
If the workup reveals true systemic ANCA-associated vasculitis (not drug-induced), then higher doses of corticosteroids or immunosuppressive agents are required according to organ involvement severity:
For generalized ANCA-associated vasculitis with organ-threatening disease, use cyclophosphamide (oral 2 mg/kg/day, max 200 mg/day, or intravenous pulses) combined with prednisolone 1 mg/kg/day (max 60 mg/day). 5
Rituximab is an alternative to cyclophosphamide for remission induction in ANCA-associated vasculitis. 5
These aggressive regimens apply only when systemic vasculitis is confirmed, not for isolated cutaneous or drug-induced disease. 5, 1, 2
Prognosis and Follow-Up
The prognosis depends on whether the disease is isolated cutaneous versus a component of systemic vasculitis, and the severity of internal organ involvement. 6
Drug-induced leukocytoclastic vasculitis has favorable prognosis with drug discontinuation alone. 2, 4
When systemic vasculitis is the underlying cause, long-term follow-up and rapid access to specialist services are necessary. 5