Medication Induced Vasculitis

Diagnosis: Medication Induced Vasculitis

Medication Induced Vasculitis

Clinical Presentation

Medication Induced Vasculitis

Clinical History

Palpable purpura, typically on lower extremities. Evaluate for systemic involvement: renal (urinalysis), joints, GI. Drug/infection history. ANCA, hepatitis panel, complement levels.

Treatment

Treat underlying cause. Mild cutaneous: leg elevation, NSAIDs, colchicine, dapsone. Severe/systemic: systemic corticosteroids + immunosuppressives (azathioprine, mycophenolate, cyclophosphamide, rituximab for ANCA-associated).

Differential Diagnosis

• Thrombocytopenic purpura • Drug eruption • Disseminated intravascular coagulation • Cellulitis • Septic emboli • Cholesterol emboli • Pigmented purpuric dermatosis

Key Learnings

• Palpable purpura is the hallmark of small-vessel vasculitis (leukocytoclastic vasculitis) • IgA vasculitis (Henoch-Schönlein purpura): most common vasculitis in children — IgA deposits • IgA vasculitis tetrad: palpable purpura, arthralgia, abdominal pain, renal involvement • Histology: fibrinoid necrosis of vessel walls with neutrophilic infiltrate and nuclear dust (leukocytoclasis) • DIF: IgA deposits in vessel walls (IgA vasculitis) • Evaluate for underlying cause: infection (HBV, HCV, strep), drugs, CTD, malignancy • ANCA-associated vasculitis: GPA (c-ANCA/PR3), MPA (p-ANCA/MPO), EGPA

Tags: dermatologist, dermatology, kodachrome, Medication Induced Vasculitis