Levamisole-Associated Purpura

Key Features

• Levamisole is a prevalent adulterant of illicit cocaine in North America

• Exposure can induce a distinctive clinical syndrome of retiform purpura and cutaneous necrosis affecting the

  • Extremities

  • Ears

  • Skin overlying the zygomatic arch

• Long-term sequelae of levamisole exposure include

  • Deforming cutaneous lesions

  • Arthralgias

  • Arthritis

Clinical Findings

• The syndrome is associated with

  • The lupus anticoagulant

  • IgM antibodies to cardiolipin

  • Very high titers of p-ANCAs (due to autoantibodies to elastase, lactoferrin, cathepsin-G, and other neutrophil components rather than to myeloperoxidase alone)

• Use of levamisole-adulterated cocaine also has been linked to

  • Neutropenia

  • Agranulocytosis

  • Pauci-immune glomerulonephritis

Diagnosis

• Biopsies reveal widespread thrombosis of small cutaneous vessels with varying degrees of vasculitis

Treatment

• There is no consensus on treatment, but early lesions can resolve with abstinence