Table 1. Classification of purpura... | American Society of Hematology

Table 1.

Classification of purpura fulminans

	Inherited	Autoimmune or postinfectious (“idiopathic”)	Acute infectious
Mechanism	Inherited PC or rarely PS deficiency	Neutralizing antibodies against PS or rarely PC	Aberrant tissue factor expression with concomitant failure of thrombomodulin-PC system
Associations		• Varicella zoster virus • Human herpesvirus 6	• Neisseria meningitidis • Haemophilus influenza • Streptococcus pneumoniae • Other encapsulated organisms • Staphylococcus aureus • Capnocytophaga canimorsus • Rickettsial infection • Plasmodium falciparum
Clinical setting	Neonatal	Within 2 weeks after viral infection	Septic shock
Rash distribution	Lower half of body > upper half	Lower half of body > upper half	Distal to proximal progression (worse in acral areas) or diffuse from onset
Laboratory findings	• Thrombocytopenia • Elevated D-dimer or fibrin split products • Hypofibrinogenemia • Prolonged PT and/or aPTT • Low PC, PS, and antithrombin activity

	Inherited	Autoimmune or postinfectious (“idiopathic”)	Acute infectious
Mechanism	Inherited PC or rarely PS deficiency	Neutralizing antibodies against PS or rarely PC	Aberrant tissue factor expression with concomitant failure of thrombomodulin-PC system
Associations		• Varicella zoster virus • Human herpesvirus 6	• Neisseria meningitidis • Haemophilus influenza • Streptococcus pneumoniae • Other encapsulated organisms • Staphylococcus aureus • Capnocytophaga canimorsus • Rickettsial infection • Plasmodium falciparum
Clinical setting	Neonatal	Within 2 weeks after viral infection	Septic shock
Rash distribution	Lower half of body > upper half	Lower half of body > upper half	Distal to proximal progression (worse in acral areas) or diffuse from onset
Laboratory findings	• Thrombocytopenia • Elevated D-dimer or fibrin split products • Hypofibrinogenemia • Prolonged PT and/or aPTT • Low PC, PS, and antithrombin activity