[Recurrent pyoderma gangrenosum-like ulcers induced by oral anticoagulants]

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

INTRODUCTION

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.

CASE REPORT

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.

CONCLUSION

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.

[Necrotic leg ulcer revealing vasculitis induced by vitamin K antagonists]

Vitamin K antagonists are widely used in thromboembolic diseases. Hemorrhagic complications related to drug overdose represent their main side effect. We report a rare side effect, a severe and unexpected type of skin vasculitis - necrotic leg ulcer - induced by vitamin K antagonist.

CASE REPORT

A 63-year-old female with a history of diabetes developed hyperalgesic necrotic ulcerations on the lower limbs one month after starting an acenocoumarol-based treatment for ischemic heart disease. Histological examination revealed lymphocytic vasculitis with fibrinoid necrosis. Etiological explorations searching for vasculitis were negative. In the absence of a precise etiology, drug-induced ulcer was suspected. Low molecular weight heparin was prescribed to replace acenocoumarol. The lesions slowly resolved with topical treatment.

DISCUSSION

The chronological criteria and the negativity of etiological explorations allowed the diagnosis of vitamin K antagonist-induced necrotic skin ulcer. Clinicians should be aware of this rare complication induced by oral anticoagulants because of its practical therapeutic implications. This is the first case of necrotic leg ulcer induced by acenocoumarol corresponding histologically to necrotising lymphocytic vasculitis.