Meningococcal septic shock — FFICM MCQ

Correct answer: A — Meningococcal septicaemia with meningitis

Meningococcal septicaemia with meningitis (A) is correct because the clinical triad of fever, neck stiffness and a rapidly spreading non-blanching purpuric rash, combined with shock and coagulopathy (platelets 38, INR 2.3) and a markedly raised lactate, is the classic presentation of fulminant meningococcaemia with disseminated intravascular coagulation. Neisseria meningitidis endotoxin triggers massive cytokine release, capillary leak and consumptive coagulopathy, producing exactly this pattern of purpura fulminans, septic shock and meningism. Current UK guidance mandates that in strongly suspected meningococcal disease, parenteral antibiotics (ceftriaxone or benzylpenicillin) are given immediately and must not be delayed for imaging, lumbar puncture or confirmatory tests, precisely because coagulopathy and shock (as here) are contraindications to safe lumbar puncture. The rapid tempo, rash morphology and multi-organ involvement (shock, coagulopathy, raised lactate) are far more consistent with meningococcal sepsis than any thrombocytopenic or vasculitic differential. Why the other options are wrong: D. Thrombotic thrombocytopenic purpura: causes microangiopathic haemolysis and thrombocytopenia but classically spares the coagulation cascade, so INR should be normal; it does not cause meningism or a purpuric rash of this rapidly spreading, septic character. E. Rocky Mountain spotted fever: not endemic to the UK, requires a tick exposure history, and would not typically present with neck stiffness as a dominant feature. B. Immune thrombocytopenia: causes isolated thrombocytopenia without coagulopathy, fever, meningism or shock, so it does not fit this multisystem septic picture. C. Henoch-Schonlein purpura: a small vessel vasculitis of children with palpable purpura, arthralgia and abdominal pain, but platelet count and coagulation are normal, and it does not cause septic shock or meningism. Key point: A rapidly evolving non-blanching rash with shock, meningism and coagulopathy is meningococcal septicaemia until proven otherwise, and antibiotics must be given immediately without waiting for CT, LP or confirmatory tests.

Reference: NICE. Meningitis (bacterial) and meningococcal disease: recognition, diagnosis and management. NICE guideline NG240 (2024). Recommendation: give IV or IM ceftriaxone or benzylpenicillin as soon as possible in strongly suspected meningococcal disease, without delaying for transfer or investigations. https://www.nice.org.uk/guidance/ng240