[7] Purpura fulminans is a presenting feature of severe acute sepsis, such as Neisseria meningitidis, Streptococcus pneumoniae, Group A and B Streptococci, and less commonly with Haemophilus influenzae, Staphylococcus aureus, Capnocytophaga canimorsus[8] or Plasmodium falciparum (malaria) infections, particularly in individuals with asplenia.

In later stage lesions, there is irreversible endothelial ischaemic injury with extravasation of blood cells into the dermis and gangrenous necrosis, sometimes with secondary infection.

Haemorrhage into the necrotic skin causes purpura fulminans lesions to become painful, dark and raised, sometimes with vesicle or blister (bulla) formation.

[2] Purpura fulminans in severe sepsis typically develops in the distal extremities and progresses proximally or appears as a generalised or diffuse rash affecting the whole body surface.

[17] In cases of severe inheritable protein C deficiency, purpura fulminans with disseminated intravascular coagulation manifests within a few hours or days after birth.

Protein C replacement is often in combination with anticoagulation therapy of injectable low molecular weight heparin or oral warfarin.

[7][23] The amount of fresh frozen plasma required to reverse disseminated intravascular coagulation associated with purpura fulminans may lead to complications of fluid overload and death, especially in neonates,[7] such as transfusion-related acute lung injury.

Once purpura fulminans lesions progress to full-thickness skin necrosis, healing takes between 4–8 weeks and leaves large scars.

[2] Purpura fulminans is often accompanied by micro-vascular thrombosis and haemorrhagic infarction in other tissues, such as the lungs, kidneys, central nervous system and adrenal glands, leading to multiple organ failure, and causes initial high mortality and long-term morbidity in survivors.

[28] Due to the rarity of purpura fulminans and its occurrence in vulnerable patient groups like children research on the condition is very limited and evidence based knowledge is scarce.

[citation needed] Case studies: Capnocytophaga canimorsus Klebsiella oxytoca Neisseria meningitidis Purpura fulminans was first described by Guelliot in 1884.