Purpura fulminans.

Purpura fulminans is the cutaneous manifestation of acute activation of the clotting mechanism resulting in massive hemorrhage due to an intravascular consumption coagulopathy. Peripheral necrotizing purpura is a warning signal, and early recognition of the clinical situation and heparin therapy may be lifesaving. Clinical manifestations and histologic features of this condition, along with its pathogenesis, treatment, and differential diagnosis are discussed.