Acute appendicitis
Summary
Definition
Acute appendicitis is an acute inflammation of the vermiform appendix, most likely due to obstruction of the lumen of the appendix (by faecolith, normal stool, infective agents, or lymphoid hyperplasia).[1][2][Figure caption and citation for the preceding image starts]: Acute appendicitis - intraoperative specimenNasim Ahmed, MBBS, FACS; used with permission [Citation ends].
History and exam
Key diagnostic factors
- abdominal pain
- anorexia
- nausea and vomiting
- right lower quadrant tenderness
- high’ or ‘intermediate’ risk score
- tense, rigid abdomen
- hypotension and tachycardia
- palpable mass
Other diagnostic factors
- age of occurrence
- low-grade pyrexia
- flushed face and a fetor
- reduced bowel sounds
- loose stool
- constipation
- flexed right hip (psoas sign)
Risk factors
- low dietary fibre
- improved personal hygiene
- smoking
Diagnostic investigations
1st investigations to order
- FBC
- CRP
- abdominal ultrasound
- contrast-enhanced abdominal CT
Investigations to consider
- urinalysis
- pregnancy test
- group and save
- abdominal MRI
Treatment algorithm
uncomplicated appendicitis: adults
uncomplicated appendicitis: children
complicated appendicitis: adults
complicated appendicitis: children
Contributors
Expert advisers
John Abercrombie, FRCS
General and Colorectal Surgeon
Queen’s Medical Centre
Nottingham
UK
Biography
JA is Clinical Lead for General Surgery, Getting It Right First Time.
Disclosures
JA is trustee and council member of the Royal College of Surgeons of England.
Acknowledgements
BMJ Best Practice would like to gratefully acknowledge the previous expert contributor, whose work is retained in parts of the content:
Dileep N. Lobo, MS, DM, FRCS, FACS
Professor of Gastrointestinal Surgery
National Institute for Health Research, Nottingham Digestive Diseases Biomedical Research Unit
Nottingham University Hospitals and University of Nottingham, Queen's Medical Centre
Nottingham
UK
DNL declares that he has no competing interests. DNL is an author of an article cited in the topic.
Peer reviewers
Sarah Richards
General Surgeon
Royal United Hospitals
Bath NHS Foundation Trust
UK
Biography
SR is a specialty advisor in emergency general surgery to the Royal College of Surgeons and an honorary senior clinical lecturer and examiner for the University of Bristol medical school.
Disclosures
SR declares that she has no competing interests.
Kokila Lakhoo, PhD, FRCS, FCS (Paediatrics) MRCPCH, MBCHB
Consultant Paediatric Surgeon
Children’s Hospital in Oxford and the University of Oxford
UK
Disclosures
KL declares that she has no competing interests.
Editors
Tessa Davis
Section Editor, BMJ Best Practice
Consultant in Paediatric Emergency Medicine
Royal London Hospital
London
UK
Disclosures
TD declares that she has no competing interests.
Annabel Sidwell
Section Editor, BMJ Best Practice
Disclosures
AS declares that she has no competing interests.
Jo Haynes
Head of Editorial, BMJ Knowledge Centre
Disclosures
JH declares that she has no competing interests.
Susan Mayor
Lead 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.
Differentials
- Acute mesenteric adenitis
- Viral gastroenteritis
- Meckel's diverticulitis
More DifferentialsGuidelines
- Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines
- Commissioning guide: emergency general surgery (acute abdominal pain)
More GuidelinesVideos
Venepuncture and phlebotomy animated demonstration
Peripheral venous cannulation animated demonstration
More videosPatient leaflets
Appendicitis
More Patient leaflets
Log in or subscribe to access all of BMJ Best Practice
Use of this content is subject to our disclaimer