[Idiopathic purpura fulminans with transient protein S deficiency].

Idiopathic purpura fulminans produces rapidly progressive hemorrhagic necrosis of the skin with disseminated intravascular coagulation in individuals without known abnormalities of the protein C pathway or acute infections. The disease mainly affects children and in 90 % of cases is preceded by a benign infection. Its pathogenesis involves a temporary autoimmune protein S deficiency that provokes a state of hypercoagulability. We present the case of a previously healthy 2-year-old boy with hemorrhagic skin lesions characteristic of purpura fulminans and disseminated intravascular coagulation without sepsis. Severe, temporary protein S deficiency was confirmed. The patient received daily replacement therapy with fresh frozen plasma for 12 days and anticoagulation with heparin for 3 months. Evolution was favorable. Although the other parameters returned to normal, protein S remained low for 50 days despite treatment. The patient has made a complete recovery.