Vitamin K antagonist-induced necrotic leg ulcer, without protein C and S deficiencies

Abstract

Patients treated by vitamin K antagonists (VKA) represent 1% of the population in France. We report a case of atypical necrotic leg ulcers induced by VKA. A 84-year-old woman was referred to our dermatology department because of necrotic leg ulcers that developed for the past 5weeks, and appeared spontaneously after the introduction of a VKA, fluindione. The etiological assessment was non contributive, in particular the search for thrombophilic factors. The skin biopsy found an aspect compatible with pyoderma gangrenosum. The outcome was favorable after discontinuing the fluindione and the switch to apixaban. A complete healing was obtained in 5months. We report an original case of necrotic leg ulcers induced by VKA without deficit of protein C or S, with a pyoderma like histology. Reported cases of ulcers induced by VKA are uncommon and the physiopathology is not well known. The involvement of VKA should be evoked in case of necrotic leg ulcer without specific etiology found.