Treatment of Leukocytoclastic Vasculitis
The cornerstone of treatment is immediate discontinuation of any offending medication, which alone often induces prompt resolution without requiring immunosuppressive therapy. 1, 2
Initial Management: Identify and Remove the Trigger
Immediately discontinue the culprit drug upon clinical suspicion – this 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
Drug discontinuation alone has a favorable prognosis in drug-induced cases and may be the only intervention needed. 2, 3
Supportive measures include rest (avoiding prolonged standing or walking) and compression stockings to reduce purpura. 3, 4
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, 4
Do not routinely use corticosteroids for isolated cutaneous disease without these severe features. 2
NSAIDs may provide symptomatic relief in mild cases but are effective only sporadically. 5, 6
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, 2, 4
Dapsone is recommended as a second-line agent for chronic or relapsing disease. 4
Azathioprine has shown effectiveness in most patients with chronic disease in clinical experience. 5
Antihistamines and antimalarials are effective only in sporadic cases. 5
Critical Pitfall: Distinguishing Drug-Induced from ANCA-Associated Systemic 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 2
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). 2, 7
Rituximab is an alternative to cyclophosphamide for remission induction in ANCA-associated vasculitis. 2, 7
These aggressive regimens apply only when systemic vasculitis is confirmed, not for isolated cutaneous or drug-induced disease. 2
Diagnostic Workup to Determine Extent of Disease
Obtain skin biopsy extending to the subcutis from the most tender, reddish or purpuric lesional skin – this is key to obtaining a significant diagnostic result. 6
Request direct immunofluorescence to distinguish IgA-associated vasculitis (Henoch-Schönlein purpura) from IgG-/IgM-associated vasculitis, which has prognostic significance. 6, 4
Basic workup should include: history of drug intake and preceding infections, differential blood count, urinalysis, throat swabs, platelet count, renal function, serological tests for hepatitis B and C, autoantibodies (ANA and ANCA), complement fractions, and IgA staining in biopsy specimens. 3, 4
Coexistence of pan-dermal small-vessel vasculitis and subcutaneous muscular-vessel vasculitis usually indicates connective tissue disease, ANCA-associated vasculitis, Behçet disease, or malignancy-associated vasculitis. 6
Refractory Cases
For refractory vasculitis, consider plasmapheresis or intravenous immunoglobulin. 6, 8
Biologic therapies such as TNF-alpha inhibitors (infliximab) and anti-B-cell antibodies (rituximab) are showing benefit in certain settings such as connective tissue disease and ANCA-associated vasculitis. 6
Follow-Up and Prognosis
Drug-induced leukocytoclastic vasculitis has favorable prognosis with drug discontinuation alone. 2
When systemic vasculitis is the underlying cause, long-term follow-up and rapid access to specialist services are necessary. 2
IgA-dominant immune complex vasculitis (HSP) has more systemic involvement and worse prognosis than IgG- or IgM-containing immune complex vasculitis. 4