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Suspected meningococcal septicaemia — MRCEM SBA MCQ

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HardInfection and sepsisSuspected meningococcal septicaemiaMRCEM SBA

A 20-year-old university student living in halls presents with fever, vomiting and a purpuric rash that has spread across his trunk and limbs over two hours. He has no headache, photophobia or neck stiffness. His GCS is 15, blood pressure 86/48 mmHg and respiratory rate 28/min. His pupils and limb examination are normal. Blood cultures and a whole-blood meningococcal PCR sample have been taken, intravenous crystalloid resuscitation is under way, and critical care review has been requested. He has no antibiotic allergy and has not received antibiotics. Which immediate treatment and lumbar puncture plan is most appropriate?

Educational content. Not a substitute for clinical judgement or local policy.

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Correct answer: E — Give intravenous ceftriaxone; avoid lumbar puncture while purpura persists; withhold dexamethasone.

The rapidly spreading purpura and shock make meningococcal disease a strong clinical suspicion even without meningism. Blood samples have already been taken, so intravenous ceftriaxone should be given immediately; NICE recommends starting antibiotics within one hour of hospital arrival. Resuscitation and critical care escalation continue in parallel. ([nice.org.uk](https://www.nice.org.uk/guidance/ng240/chapter/Recommendations)) **E** also respects a separate contraindication to lumbar puncture: extensive or rapidly spreading purpura. **A** recognises that shock must be treated before lumbar puncture, but resolving shock alone would not remove the purpura-related contraindication. **B** imports the dexamethasone recommendation for strongly suspected bacterial meningitis into a presentation of meningococcal septicaemia without clinical evidence of meningitis; corticosteroids are not routine for meningococcal disease. Replacement-dose corticosteroids may be considered later if meningococcal septic shock does not respond to high-dose vasoactive agents. **C** proposes imaging despite no focal feature or reduced consciousness indicating it, and a normal CT would not make lumbar puncture appropriate during extensive purpura. **D** uses an antibiotic that may be given before hospital arrival, whereas NICE specifies intravenous ceftriaxone for suspected meningococcal disease *in hospital*. ([nice.org.uk](https://www.nice.org.uk/guidance/ng240/chapter/Recommendations))

Reference: NICE NG240: Meningitis (bacterial) and meningococcal disease — Recommendations (19 March 2024) — https://www.nice.org.uk/guidance/ng240/chapter/Recommendations NICE NG240: Lumbar puncture and corticosteroid recommendations (19 March 2024) — https://www.nice.org.uk/guidance/ng240/chapter/Recommendations NICE NG253: Managing suspected sepsis (19 November 2025) — https://www.nice.org.uk/guidance/ng253/chapter/Managing-suspected-sepsis