What is the treatment approach for a patient with leukocytoclastic vasculitis?

Treatment of Leukocytoclastic Vasculitis

Immediately discontinue any suspected culprit medication, as this alone often induces prompt resolution without requiring immunosuppressive therapy in drug-induced cases. 1, 2

Initial Management: Drug Discontinuation

• Stop the offending drug immediately upon clinical suspicion—this is the cornerstone of treatment and critical to control the vasculitis and prevent relapses 1, 2
• Common culprit medications include hydralazine, propylthiouracil, levamisole-adulterated cocaine, minocycline, levetiracetam, and warfarin 1, 2
• Drug-induced leukocytoclastic vasculitis has favorable prognosis with drug discontinuation alone 1

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, 3

• Do not routinely use corticosteroids for isolated cutaneous disease without these severe features 1
• For mild cutaneous disease, rest (avoiding standing or walking) and compression stockings are sufficient 3

Treatment for Chronic or Relapsing Disease

Use colchicine 0.6 mg twice daily as first-line treatment for patients with chronic or relapsing cutaneous leukocytoclastic vasculitis. 1, 2, 3

• Colchicine has an effective and better safety profile than long-term corticosteroids 1, 2
• Dapsone can be considered as second-line therapy if colchicine fails 3

Critical Pitfall: Distinguishing Drug-Induced from ANCA-Associated Vasculitis

Do not treat drug-induced or isolated cutaneous leukocytoclastic vasculitis with cyclophosphamide or rituximab—these aggressive immunosuppressants are reserved for true ANCA-associated systemic vasculitis and carry significant toxicity. 1, 2

Diagnostic clues suggesting 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, 2
• In levamisole-induced cases: neutropenia and retiform purpuric rash 1

When Systemic Vasculitis is Confirmed

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). 4, 1

• Rituximab is an alternative to cyclophosphamide for remission induction in ANCA-associated vasculitis 4, 1
• These aggressive regimens apply only when systemic vasculitis is confirmed, not for isolated cutaneous or drug-induced disease 1, 2
• Patients with AAV should be managed in close collaboration with, or at, centers of expertise 4

Diagnostic Workup

Perform skin biopsy with immunofluorescence to confirm leukocytoclastic vasculitis and identify the dominant immunoglobulin. 5, 3

Essential laboratory tests include:

• Complete blood count with differential 5, 3
• Renal function and urinalysis (to detect glomerulonephritis) 5, 3
• Hepatitis B and C serology 5
• ANCA testing (PR3-ANCA and MPO-ANCA) 5, 3
• ANA and complement levels (C3, C4) 5, 3
• IgA levels if IgA vasculitis (Henoch-Schönlein purpura) is suspected 5, 3

Prognosis and Follow-Up

• Drug-induced leukocytoclastic vasculitis has favorable prognosis with drug discontinuation alone 1
• When systemic vasculitis is the underlying cause, long-term follow-up and rapid access to specialist services are necessary 1
• The prognosis depends on the underlying disease and severity of internal organ involvement 5, 6