Makindo Medical Notes

🩸 Introduction

Purpura fulminans is a rare, life-threatening thrombotic and hemorrhagic emergency characterised by rapidly progressive skin necrosis, disseminated intravascular coagulation (DIC), and septic shock. It demands immediate recognition and aggressive multidisciplinary treatment to prevent death or limb loss.

📖 Definition and Classification

Purpura fulminans is defined by the sudden onset of widespread purpura that evolves into hemorrhagic skin necrosis due to microvascular thrombosis and DIC. It is classically divided into three main categories:

• 🦠 Acute Infectious Purpura Fulminans: The most frequent type, typically triggered by severe bacterial sepsis (e.g. Neisseria meningitidis, Streptococcus pneumoniae, or Haemophilus influenzae). It is often preceded by a viral or respiratory infection and occurs mainly in children under 7 years or in those with asplenia.
• 👶 Neonatal Purpura Fulminans: Occurs within days of birth and is caused by congenital deficiency of protein C, protein S, or antithrombin III. These infants develop widespread purpura and DIC soon after delivery.
• 🧩 Idiopathic / Autoimmune Purpura Fulminans: Rare, occurring without infection, sometimes after viral illness or in association with autoimmune disease (e.g. lupus, antiphospholipid syndrome).

🧠 Pathophysiology

The core mechanism is widespread microvascular thrombosis with secondary hemorrhagic necrosis. Endotoxins or inflammatory cytokines trigger massive activation of the coagulation cascade, depleting protein C, protein S, and antithrombin III. This imbalance between pro- and anti-coagulant forces leads to fibrin deposition in small vessels, tissue ischemia, and necrosis. As DIC develops, thrombocytopenia and consumptive coagulopathy cause bleeding and rapid progression of skin lesions.

💡 Teaching tip: Think of purpura fulminans as a catastrophic loss of endothelial control — “clotting and bleeding at once”. In meningococcal sepsis, plasma protein C falls sharply within hours, amplifying vascular injury.

⚕️ Clinical Features

• 🔴 Early: petechial rash that rapidly coalesces into purpuric patches, especially on the extremities, buttocks, and trunk.
• 🩹 Progression: lesions become ecchymotic and necrotic with well-demarcated black eschars.
• 🌡️ Systemic signs: fever, tachycardia, hypotension, and features of septic shock.
• 🧮 Laboratory: thrombocytopenia, prolonged PT/APTT, low fibrinogen, and high D-dimer consistent with DIC.
• 🦵 Severe cases: symmetrical peripheral gangrene and tissue loss requiring amputation or grafting.

💊 Management and Treatment

Purpura fulminans is a medical and surgical emergency requiring coordinated critical care.

• 🚨 Resuscitation: Immediate IV access, fluid resuscitation, and inotropic support as per sepsis protocol. Transfer to ICU early.
• 💉 Antibiotics: Start broad-spectrum IV antibiotics immediately after cultures (e.g. ceftriaxone ± vancomycin if meningococcal sepsis suspected).
• 🧬 Replacement therapy: In congenital cases, give protein C concentrate or FFP to restore anticoagulant levels. Consider heparin in selected non-bleeding cases with extensive thrombosis under specialist advice.
• 🩸 Supportive care: Correct coagulopathy with platelets and cryoprecipitate as needed. Manage DIC per haematology guidance.
• 🔪 Surgical management: Early surgical review for debridement of necrotic tissue once stable. Vacuum-assisted closure and staged grafting may help wound healing.
• 🌡️ Adjuncts: Maintain normothermia, correct hypoglycaemia, and monitor renal and hepatic function closely.

📉 Prognosis

Despite optimal management, mortality remains high — typically 30–50% — due to overwhelming sepsis and multiorgan failure. Survivors often require reconstructive surgery and psychological rehabilitation due to limb or skin loss.

🧠 Key learning: Early recognition of a rapidly spreading purpuric rash in a toxic or hypotensive patient is vital — treat first, confirm later. Immediate antibiotics and intensive care input can be lifesaving.