AKT · Neurology/Infection & structural

Meningitis

Meningococcus/pneumococcus (adults); Listeria, Hib; viral (enterovirus)

Overview

Inflammation of the meninges. The neuro emphasis is the CSF interpretation (bacterial vs viral vs TB vs fungal) and the do-not-delay-antibiotics rule. Community non-blanching rash → immediate benzylpenicillin; hospital → IV ceftriaxone (± amoxicillin for Listeria) + dexamethasone for pneumococcal.

Recognise

Fever, headache, neck stiffness, photophobia, vomiting; reduced GCS
Non-blanching petechial/purpuric rash = meningococcal septicaemia
Kernig/Brudzinski signs; infants: bulging fontanelle, poor feeding, irritability

Red flags

Non-blanching rash, septic shock, reduced GCS, focal signs/seizures, raised-ICP signs → do not delay antibiotics

Differentials & how to tell them apart

Subarachnoid haemorrhagethunderclap, no fever; CT/xanthochromia

Encephalitisaltered behaviour/cognition + seizures dominate → add aciclovir

Migraineno fever/meningism/rash

Viral vs bacterial meningitisCSF: bacterial = neutrophils, high protein, LOW glucose; viral = lymphocytes, normal glucose

Investigations

Blood cultures + LP (CSF microscopy/culture/PCR, glucose, protein) — but antibiotics first if it would delay; CT before LP only if raised-ICP/focal signs. See the CSF interpretation panel below.

Management

Community + rash: benzylpenicillin now; hospital: IV ceftriaxone (± amoxicillin) ± dexamethasone

1Community with suspected meningococcal disease → IM/IV benzylpenicillin immediately, transfer. Hospital → blood cultures then empirical IV ceftriaxone without delay.Gate: Do NOT delay antibiotics for the LP; do CT before LP only if raised ICP/focal neurology/reduced GCS
2Add amoxicillin if Listeria risk; dexamethasone for suspected pneumococcal; notify public health; ciprofloxacin prophylaxis for close contacts.

Benzylpenicillin IM/IV — community, suspected meningococcal disease (non-blanching rash) — give before transfer

Ceftriaxone IV — empirical hospital treatment

Amoxicillin — add for Listeria cover (>50y, immunocompromised, pregnant)

Dexamethasone — with/just before antibiotics in suspected pneumococcal meningitis

Key points

CSF pattern is the high-yield neuro skill (bacterial vs viral vs TB vs fungal — see panel). Antibiotics before LP if delay. Notifiable + contact prophylaxis.

Monitor & prognosis

GCS, haemodynamics, CSF/PCR, complications (hearing, seizures).

Meningococcal septicaemia can be rapidly fatal; early antibiotics are key.

Source: NICE NG240 (meningitis)