Clinical features of purpura fulminans:
(1) abrupt onset of ecchymoses
(2) widespread thrombosis in blood vessels
(3) fever
(4) skin and organ necrosis
(5) hypotension
(6) thrombocytopenia with laboratory findings of DIC
Features of the protein C deficiency:
(1) The patient will have a marked deficiency of protein C (< 1% of normal), usually associated with a homozygous or double heterozygous deficiency.
(2) The parents are heterozygous for the protein C defect.
(3) Consanguinity may be present in the family.
The patient may have recurrent episodes of purpura fulminans and/or deep vein thrombosis unless anticoagulation therapy is given.
Differential diagnosis:
(1) DIC due to other cause