Last reviewed: 28 Sep 2021
Last updated: 05 Aug 2021

Summary

Definition

History and exam

Key diagnostic factors

  • fever
  • headache
  • vomiting/nausea
  • stiff neck
  • photophobia
  • rash
  • rapid deterioration
  • altered mental state
  • unusual skin colour
  • shock
  • hypotension
  • aching legs
  • cold peripheries
  • back rigidity
  • bulging fontanelle
  • Kernig’s sign
  • Brudzinksi’s sign
  • unconsciousness
  • toxic/moribund state
  • paresis
  • focal neurological deficit including cranial nerve involvement and abnormal pupils
  • seizures
  • presence of risk factors

Other diagnostic factors

  • lethargy
  • irritable/unsettled
  • ill appearance
  • refusing food/drink
  • muscle ache/joint pain
  • respiratory distress or breathing difficulty
  • chills/shivering
  • diarrhoea, abdominal pain/distension
  • sore throat/coryza or other ear, nose, and throat symptoms/signs

Risk factors

  • young age
  • complement deficiency
  • use of eculizumab and ravulizumab
  • immunoglobulin deficiency
  • asplenia or hyposplenia
  • university attendance
  • close contact with invasive meningococcal infection
  • household crowding
  • travel to a hyperendemic or epidemic area
  • laboratory workers
  • recent move into a new community
  • tobacco smoke exposure
  • respiratory infection
  • visiting bars/clubs
  • kissing

Diagnostic investigations

1st investigations to order

  • blood gases
  • blood cultures
  • lactate
  • glucose
  • full blood count
  • urea, electrolytes and creatinine, Ca2+, Mg2+, PO4-
  • coagulation profile
  • procalcitonin (or CRP)
  • liver function
  • cross-match (children)
  • PCR for Neisseria meningitidis
  • CFS PCR for Neisseria meningitidis and Streptococcus pneumoniae
  • PCR for Streptococcus pneumoniae (adults)
  • CSF white blood cell count and examination
  • CSF total protein concentration
  • CSF glucose concentration
  • CSF microscopy, Gram stain, culture and sensitivities
  • CSF lactate (adults)
  • throat swab for culture

Investigations to consider

  • cranial CT
  • complement deficiency (children)
  • serum HIV (adults)

Treatment algorithm

Contributors

Expert advisers

Alexander Alexiou, MBBS, BSc, DCH, FRCEM, Dip IMC RCSEd

Flight Doctor

Greater Sydney Area

Helicopter Emergency Medical Service

New South Wales

Australia

Disclosures

AA declares that he has no competing interests.

Acknowledgements,

BMJ Best Practice would like to gratefully acknowledge the previous expert contributor, whose work has been retained in parts of the content:

Elisabeth Adderson, MD

Associate Member

St. Jude Children's Research Hospital

Associate Professor of Pediatrics

University of Tennessee Health Sciences Center

Memphis

TN

Disclosures

EA declares that she has no competing interests.

Peer reviewers

Robert Taylor, MBChB, MRCP(UK), MRCP(London), DipMedTox, DipTher PGDME, FHEA FRCEM

Acute Hospital Sub Dean (Cornwall)

Honorary Clinical Senior Lecturer

Consultant Emergency Physician

The Knowledge Spa

Royal Cornwall Hospital

Truro

UK

Disclosures

RT declares that he has no competing interests.

Brian Angus, BSc, MBChB, DTM&H, FRCP, MD, FFTM

Consultant in Infectious Diseases

Clinical Tutor in Medicine and Associate Professor and Reader in Infectious Diseases

University of Oxford

Director

Oxford Centre for Clinical Tropical Medicine and Global Health

Oxford

UK

Disclosures

BA declares that he has no competing interests.

Editors

Susan Mayor,

Section Editor, BMJ Best Practice

Disclosures

SM works as a freelance medical journalist and editor, video editorial director and presenter, and communications trainer. In this capacity, she has been paid, and continues to be paid, by a wide range of organisations for providing these skills on a professional basis. These include: NHS organisations, including the National Institute for Health and Care Excellence, NHS Choices, NHS Kidney Care, and others; publishers and medical education companies, including the BMJ Group, the Lancet group, Medscape, and others; professional organisations, including the British Thoracic Oncology Group, the European Society for Medical Oncology, the National Confidential Enquiry into Patient Outcome and Death, and others; charities and patients’ organisations, including the Roy Castle Lung Cancer Foundation and others; pharmaceutical companies, including Bayer, Boehringer Ingelheim, Novartis, and others; and communications agencies, including Publicis, Red Healthcare and others. She has no stock options or shares in any pharmaceutical or healthcare companies; however, she invests in a personal pension, which may invest in these types of companies. She is managing director of Susan Mayor Limited, the company name under which she provides medical writing and communications services.

Tannaz Aliabadi-Oglesby,

Lead Section Editor, BMJ Best Practice

Disclosures

TAO declares that she has no competing interests.

Julie Costello,

Comorbidities Editor, BMJ Best Practice

Disclosures

JC declares that she has no competing interests.

Adam Mitchell,

Drug Editor, BMJ Best Practice

Disclosures

AM declares that he has no competing interests.

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