Warfarin-induced leukocytoclastic vasculitis.

Skin reactions associated with oral coumarin-derived anticoagulants are an uncommon occurrence. Leukocytoclastic vasculitis (LV) is primarily a cutaneous small vessel vasculitis, though systemic involvement may be encountered. We report 4 patients with late-onset LV probably due to warfarin. All 4 patients presented with skin eruptions that developed after receiving warfarin for several years. The results of skin lesion biopsies were available in 3 patients, confirming LV. Cutaneous lesions resolved in all patients after warfarin was discontinued. In 2 of the 4 patients, rechallenge with warfarin led to recurrence of the lesions. LV may be a late-onset adverse reaction associated with warfarin therapy.