Subcutaneous (SC) protein C (PC) was used in a child with purpura fulminans secondary to severe congenital PC deficiency. For maintenance, PC 80-120 IU/kg, given over 60-90 min SC Q48hr, has been successful as a home therapy for more than 3 years. The treatment was monitored by measuring trough PC chromogenic activity (target ≥15%) and D-dimer levels. No change in clinical course was appreciated after discontinuing enoxaparin (and leaving the patient on prophylactic PC replacement alone). A significant discrepancy between clotting-based and chromogenic-based PC activity is shown.