A 3.5-year-old boy presented with purpura on the buttocks extending towards both legs. Two weeks earlier, he had had chickenpox. Because of the rapidly progressing purpura with clinical signs of hypovolaemic shock, he was treated with fresh frozen plasma, packed red blood cells, intravenous immunoglobulins, prednisolone, acyclovir and ceftriaxone. The purpura stopped spreading. In the next few days, the skin at the site of the purpura became necrotic and was excised, as was the subcutis and part of the fascia on both legs and flanks. The right lower leg was amputated and a temporary colostomy was created to prevent faecal contamination of the wounds. The patient recovered and was discharged after three months. Purpura fulminans is a rare complication after a primary infection with varicella zoster virus. A varicella infection may lead to protein S deficiency resulting in diffuse intravascular coagulation and severe skin defects.