Management of severe congenital protein C deficiency with a direct oral anticoagulant, edoxaban: A case report.

A male patient diagnosed with severe congenital protein C (PC) deficiency during the neonatal period was treated with long-term warfarin but frequently developed purpura fulminans and bleeding. At four years of age, edoxaban was initiated (direct oral anticoagulant [DOAC]). His d-dimer and fibrin/fibrinogen degradation product levels were closely monitored. His PC activity increased from below the sensitivity range to 17%; this increase was thought to be due to a reduction in PC consumption during edoxaban therapy. After edoxaban introduction, he experienced just one episode of purpura fulminans over two years without any adverse events. Thus, DOAC may be a promising alternative for the management of congenital PC deficiency.