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

Treatment of Leukocytoclastic Vasculitis

The treatment of leukocytoclastic vasculitis depends critically on whether it is isolated cutaneous disease versus organ-threatening systemic vasculitis: isolated cutaneous LCV requires only conservative management with drug withdrawal if applicable, while organ-threatening disease demands immediate aggressive immunosuppression with cyclophosphamide or rituximab plus glucocorticoids. 1, 2

Initial Assessment: Distinguish Cutaneous from Systemic Disease

The first priority is determining disease extent and identifying any underlying cause 3, 4:

• Perform urinalysis at every visit to screen for glomerulonephritis (hematuria, proteinuria, red cell casts) 5
• Check complete blood count, renal function, liver function 5
• Obtain ANCA testing, cryoglobulins, autoantibodies (ANA, RF), complement levels (C3, C4), hepatitis B/C serology 1, 3
• High-titer MPO-ANCA or dual MPO/PR3 positivity suggests drug-induced vasculitis rather than primary ANCA-associated vasculitis 2
• Assess for systemic symptoms: fever, arthralgia, abdominal pain, neurologic deficits, pulmonary hemorrhage 3, 6
• Obtain skin biopsy with immunofluorescence to confirm leukocytoclastic vasculitis and identify dominant immunoglobulin (IgA, IgG, IgM) 3, 4

Treatment Algorithm Based on Disease Severity

For Isolated Cutaneous LCV (No Organ Involvement)

Conservative management is sufficient and aggressive immunosuppression should be avoided 1, 2:

• Immediately discontinue any suspected causative medication (antibiotics, NSAIDs, diuretics, anticonvulsants, antiarrhythmics) - this alone often induces resolution 2, 3
• Common culprits include hydralazine, propylthiouracil, levamisole-adulterated cocaine, minocycline, levetiracetam, warfarin, and amiodarone 1, 2
• Rest with leg elevation and compression stockings to reduce purpura 4
• Add systemic corticosteroids (prednisolone 1 mg/kg/day, maximum 60 mg/day) only if there are signs of incipient skin necrosis or severe systemic symptoms 2, 4
• For chronic or relapsing cutaneous LCV: colchicine as first-line therapy, dapsone as second-line 4

For Organ-Threatening or Life-Threatening Disease

If LCV involves kidneys (glomerulonephritis), lungs (pulmonary hemorrhage), peripheral nerves (mononeuritis multiplex), or other organs, this constitutes organ-threatening ANCA-associated vasculitis requiring immediate aggressive treatment 5, 1, 6:

• Remission induction: glucocorticoids PLUS either cyclophosphamide OR rituximab 5
• Consider plasma exchange for rapidly progressive renal failure or pulmonary hemorrhage 5
• Refer immediately to rheumatology or nephrology 1
• After remission induction, transition to maintenance therapy with azathioprine, methotrexate, or rituximab 5

Critical Pitfall to Avoid

Do not confuse drug-induced leukocytoclastic vasculitis with primary ANCA-associated vasculitis 2:

• Drug-induced LCV resolves with medication discontinuation and does not require cyclophosphamide or rituximab 2
• The EULAR/KDIGO guidelines for ANCA-associated vasculitis do NOT apply to drug-induced vasculitis 2
• Clues favoring drug-induced: high-titer MPO-ANCA, dual ANCA positivity, positive ANA/antihistone antibodies, discordance between immunofluorescence and ELISA ANCA testing 2

Monitoring and Follow-Up

For patients with systemic involvement 5:

• Urinalysis at every clinic visit to detect renal relapse 5
• Monitor inflammatory markers (ESR, CRP) and renal function every 1-3 months 5
• Full blood count and liver function tests at similar intervals to screen for drug toxicity 5
• Monitor blood glucose while on glucocorticoid therapy 5
• Investigate persistent unexplained hematuria in patients with prior cyclophosphamide exposure for bladder cancer risk 5

Prognosis

• Isolated cutaneous LCV, especially drug-induced, has favorable prognosis with drug discontinuation 3, 4
• IgA-dominant LCV (Henoch-Schönlein purpura) has higher risk of systemic involvement in both children and adults 4
• Prognosis depends on underlying disease and severity of organ involvement 3, 7
• LCV as component of Wegener's granulomatosis has worse prognosis than as component of Henoch-Schönlein purpura 7