About This Page
This is a clinician-written, evidence-based summary aligned to the 2026 MLA Content Map. It is intended for medical students and junior doctors preparing for the UKMLA. Always cross-reference with NICE guidance, local protocols, and clinical judgement.
The Bottom Line
- Classic triad: headache, neck stiffness, photophobia — but may be incomplete, especially in young children and elderly
- Bacterial meningitis is a MEDICAL EMERGENCY — do NOT delay antibiotics for lumbar puncture
- Empirical treatment: IV ceftriaxone (+ amoxicillin if >60 years or immunocompromised for Listeria cover)
- IV dexamethasone 0.15 mg/kg QDS for 4 days — give with or just before first dose of antibiotics (reduces hearing loss in pneumococcal meningitis)
- Commonest organisms: Neisseria meningitidis (young adults), Streptococcus pneumoniae (all ages), Group B Strep (neonates)
- Public health: notify and offer chemoprophylaxis (ciprofloxacin) to close contacts of meningococcal cases
Overview
Meningitis is inflammation of the leptomeninges (pia and arachnoid mater) and CSF. Bacterial meningitis is a medical emergency with mortality of 15–20% even with treatment. Viral meningitis is more common but usually self-limiting. The most important clinical distinction is between bacterial (requires immediate antibiotics) and viral (supportive care). Key bacterial pathogens vary by age: neonates (Group B Streptococcus, E. coli, Listeria), children/young adults (Neisseria meningitidis, S. pneumoniae), older adults (S. pneumoniae, Listeria, N. meningitidis).
Epidemiology
Bacterial meningitis has an incidence of approximately 2–5 per 100,000 per year in the UK. N. meningitidis (meningococcal) is the most common cause in adolescents and young adults. S. pneumoniae is the most common in adults overall and carries the highest mortality (~25%). Listeria monocytogenes affects neonates, elderly, pregnant women, and immunocompromised patients. Viral meningitis is much more common — enteroviruses are the most frequent cause. The introduction of conjugate vaccines (MenB, MenACWY, PCV, Hib) has significantly reduced incidence.
Clinical Features
Symptoms
Severe headache — often described as the worst headache of their life
Neck stiffness (meningism)
Photophobia
Fever
Nausea and vomiting
Altered consciousness, confusion, drowsiness
Seizures
Non-blanching petechial/purpuric rash (meningococcal septicaemia)
In neonates/infants: irritability, poor feeding, bulging fontanelle, high-pitched cry, floppy
Signs
Neck stiffness (inability to passively flex neck to chest)
Kernig's sign: pain/resistance on extending knee with hip flexed
Brudzinski's sign: involuntary hip/knee flexion on passive neck flexion
Non-blanching purpuric rash (meningococcal disease) — check with glass test
Pyrexia (may be absent in immunocompromised or neonates)
Reduced GCS, focal neurological signs (suggests complication: abscess, venous sinus thrombosis)
Signs of raised ICP: papilloedema, Cushing response (hypertension, bradycardia, irregular breathing)
Investigations
First-line
Blood culturesTake BEFORE antibiotics but do NOT delay treatment for cultures
BloodsFBC, CRP, U&Es, glucose (paired with CSF glucose), coagulation, lactate, blood gas
Lumbar puncture (LP)Gold standard — send CSF for: MC&S, protein, glucose (pair with blood glucose), PCR (meningococcal, pneumococcal, viral panel). DO NOT delay antibiotics to wait for LP
Second-line
CT head (before LP)Required BEFORE LP if: focal neurology, reduced GCS, papilloedema, seizures, immunocompromised — to exclude raised ICP/mass lesion
CSF interpretationBacterial: turbid, high WCC (neutrophils), high protein, LOW glucose (<50% blood glucose), positive Gram stain/culture. Viral: clear, lymphocytes, mildly raised protein, NORMAL glucose. TB: lymphocytes, very high protein, very low glucose
Specialist
CSF PCRMeningococcal, pneumococcal, HSV, enterovirus — more sensitive than culture, especially if antibiotics already given
MRI brainIf complications suspected: cerebral abscess, subdural empyema, venous sinus thrombosis
1
Pre-hospital (GP/ambulance)
- If meningococcal disease suspected (non-blanching rash + fever): give IM/IV benzylpenicillin immediately and transfer urgently
- Do NOT delay transfer for investigations
2
Empirical antibiotics — give IMMEDIATELY
- IV ceftriaxone 2 g BD (or cefotaxime 2 g QDS)
- Add IV amoxicillin 2 g 4-hourly if age >60, immunocompromised, or pregnant (Listeria cover)
- Neonates: IV cefotaxime + amoxicillin (or ampicillin)
- Do NOT delay antibiotics for lumbar puncture or CT scan
3
Adjunctive dexamethasone
- IV dexamethasone 0.15 mg/kg QDS for 4 days
- Give with or just BEFORE first dose of antibiotics
- Proven benefit in pneumococcal meningitis — reduces hearing loss and neurological sequelae
- Discontinue if non-pneumococcal meningitis confirmed (debatable benefit in meningococcal)
4
Supportive care
- ABCDE assessment, continuous monitoring
- IV fluids — avoid overhydration (risk of cerebral oedema)
- Seizure management: IV lorazepam
- Monitor for complications: raised ICP, SIADH, DIC, septic shock
5
Public health — meningococcal disease
- Notify Public Health England immediately (notifiable disease)
- Chemoprophylaxis for close contacts: single dose ciprofloxacin 500 mg PO (or rifampicin for 2 days)
- Close contacts = household, kissing contacts, healthcare workers with unprotected exposure to respiratory secretions
Complications
- Sensorineural hearing loss: Most common long-term complication — screen all patients post-recovery (audiometry)
- Cerebral oedema and raised ICP: Can cause herniation — monitor GCS, may need osmotherapy
- Seizures: Acute seizures in ~20% — may develop late epilepsy
- Subdural empyema / cerebral abscess: Suspect if not improving or new focal signs
- Hydrocephalus: Communicating hydrocephalus from meningeal adhesions
- Waterhouse-Friderichsen syndrome: Bilateral adrenal haemorrhage in meningococcal septicaemia — fulminant DIC and shock
- Cognitive and behavioural sequelae: Memory impairment, concentration difficulties, personality changes
UKMLA Exam Tips
- 1DO NOT DELAY ANTIBIOTICS — give empirical ceftriaxone immediately if bacterial meningitis suspected
- 2CT before LP is only needed if: GCS <12, focal neurology, papilloedema, seizures, immunocompromised
- 3Bacterial CSF: turbid, neutrophils, high protein, LOW glucose. Viral: clear, lymphocytes, normal glucose
- 4Non-blanching rash + fever = meningococcal disease until proven otherwise — give benzylpenicillin pre-hospital
- 5Dexamethasone: give BEFORE or WITH first antibiotic dose. Stops after 4 days. Main benefit = pneumococcal meningitis
- 6Add amoxicillin if >60 years to cover Listeria — ceftriaxone does NOT cover Listeria
- 7Chemoprophylaxis for meningococcal contacts: ciprofloxacin single dose (NOT the patient — they get ceftriaxone)
practicetest your knowledge on meningitisApply what you've learnt with UKMLA-style questions from the iatroX Q-Bank — neurology and beyond.
open q-bank