Warfarin-induced skin necrosis

Background

• Differing half-lives of Vitamin-K dependent coagulation factors leads to relative protein C deficiency initially→ hypercoagulability
• Onset usually in first week of starting warfarin

Clinical Features

Right leg affected by warfarin necrosis.

• Painful, red lesions over extremities, trunk, penis
• Start with erythematous macule→ edema→ central purpuric zones → necrosis

Differential Diagnosis

Necrotizing rashes

• Necrotizing soft tissue infections
  • Necrotizing fasciitis
  • Necrotizing myositis
  • Necrotizing cellulitis
• Purpura fulminans
• Drug rash
• Levamisole toxicity
• Heparin-induced skin necrosis
• Warfarin-induced skin necrosis

Evaluation

• Clinical diagnosis

Management

• Stop warfarin
• Low molecular weight heparin or unfractionated heparin