Warfarin Induced Skin Necrosis

BY: MOHAMMED ALSAIDAN

Warfarin induced skin necrosis

• (WISN) affects 0.01% to 0.1% of patients on warfarin

• 3 to 10 days after the initiation of therapy

• In areas with increased subcutaneous fat such as the abdomen, buttocks, thighs, legs, and mammary tissue

• 33% multiple sites.

Warfarin induced skin necrosis

• Acute onset of paresthesia and edema petechiae and ecchymosis well-demarcated hemorrhagic bullae within 24 hours painful coagulative full-thickness skin necrosis with formation of deep subcutaneous ulcers

Warfarin induced skin necrosis

VKAs

• Coumarin derivatives :• Bishydroxycoumarin (Dicumarol)• Warfarin (Coumadin®)

• Analog #42 (1945) of many coumarins synthesized by Dr Link and named by him as WARFarin for the Wisconsin Alumni Research Foundation and coumARIN

Pathophysiology

Histopathology

• Diffuse microthrombi within dermal and subcutaneous capillaries, venules, and deep veins

• Endothelial cell damage resulting in ischemic skin necrosis and marked RBC extravasation

• No vascular inflammation and arterial involvement

Management

• Early diagnosis and drug withdrawal improve prognosis

• (Fresh frozen plasma, vitamin K) +/- Heparin

• Systemic antibiotic

• Protein C concentrates

• Local treatment• topical bactericidal agents• surgical debridement +/- skin grafting,• mastectomy, or amputation

Warfarin Again?

• Controversy