Purpura fulminans is an infectious syndrome that represents an extremely severe form of sepsis. It causes blood to clot and tissue necrosis. It is very often caused by an invasive meningococcal infection and its outcome is fatal if not taken care of in time.

High fever, profound impairment of general condition, vomiting and abdominal pain are the first uncharacteristic symptoms. One or more red and purple spots spread quickly on the skin, often on the lower limbs. This is purpura, the bleeding lesion of the skin. Pressure on the skin does not flush the blood and does not make the stain disappear momentarily, a sign of the “extravasation” of the blood in the tissues. This is because Purpura Fulminans causes disseminated intravascular coagulation (DIC), which is the formation of small clots that will disrupt blood flow (a thrombosis), directing it to the dermis and causing hemorrhage and necrosis of skin tissue. The infectious syndrome can be accompanied by a state of shock or disturbances of consciousness of the affected person.

In the vast majority of cases, purpura fulminans is linked to an invasive and severe bacterial infection. Neisseria meningitidis (meningococcus) is the most common infectious agent involved, accounting for approximately 75% of cases. The risk of developing purpura fulminans occurs in 30% of invasive meningococcal infections (IIMs). (2) 1 to 2 cases of IMD per 100 inhabitants occur each year in France, with a case fatality rate of around 000%. (10)

Other bacterial agents may be responsible for the development of purpura fulminans, such as Streptococcus pneumoniae (pneumococcus) or Haemophilus influenzae (Pfeiffer’s bacillus). Sometimes the cause is a deficiency in protein C or S, which play a role in coagulation, due to an inherited genetic abnormality: a mutation of the PROS1 gene (3q11-q11.2) for protein C and PROC gene (2q13-q14) for protein C. It should be noted that purpura fulgurans can result from a mild infection such as chickenpox, in extremely rare cases.

Purpura fulminans can affect any age, but infants under 15 year of age and adolescents 20 to 1 years old are at greater risk. (XNUMX) People who have been in close contact with the victim of septic shock should receive prophylactic treatment to prevent any risk of infection.

The prognosis is directly linked to the time taken to take charge. Purpura fulminans indeed represents a clinical situation of extreme urgency which requires an antibiotic treatment as early as possible, without waiting for the confirmation of the diagnosis and not subjected to the preliminary results of a blood culture or a blood test. A purpura consisting of at least one spot with a diameter greater than or equal to 3 millimeters, should immediately trigger the alert and treatment. Antibiotic therapy should be appropriate for meningococcal infections and performed intravenously or, failing that, intramuscularly.