UMEM Educational Pearls

Title: Warfarin Induced Skin Necrosis

Category: Vascular

Keywords: Warfarin, Skin Necrosis (PubMed Search)

Posted: 12/1/2008 by Rob Rogers, MD (Updated: 11/22/2024)
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Warfarin-Induced Skin Necrosis (WISN)

Some pearls about a rare, but serious side effect of Warfarin...

WISN Occurs in 0.01-0.1% of patients taking Warfarin
More common in middle-age, perimenopausal women being treated for DVT/PE
Symptoms usually begin on days 3-6 of Warfarin treatment
Underlying pathophysiology is complex but involves thrombosis of superficial dermal capillaries
Postulated to be associated with deficiencies of protein C, protein S, and antithrombin III
Rash is most common on the breats, with thighs/buttocks being second most common site (see picture)
Diagnosis usually made clinically based on appearance of rash
Treatment is aimed at restoring Vitamin K dependent clotting factors by administering Vit K and FFP
For patients with the need for anticoagulation (DVT/PE, etc.) Heparin therapy is usually started

55 yo female presented to the ED on the day of hospital discharge for evaluation of this rash.

The rash began 4 days after starting Warfarin. Was being treated for a DVT.