Please register or login to view the chart

Acute Appendicitis

Appendicitis is an inflammation of the inner lining of the vermiform appendix

Appendix is continuation of the caecum and is first delineated during 5th month of gestation Worm-like extension –> hence called Vermiform Average length is 8-10 cm ( range 2-20 cm ) Has no fixed position ( hence the variation in presentation and diagnostic difficulty )

No longer thought as vestigeal -repository for commensal bacteria that assist in normal digestive processes and may allow for recolonization of the intestinal flora in times of enteric bacterial destruction ( Rosen’s )

Faecolith Normal stool Lymphoid hyperplasia Indigestible food Mucus Parasites Tumours-Increased intraluminal pressure Bacterial overgrowth Ischaemia Necrosis-Perforation & other complications as
Appendix mass Adhesions
Appendix abscess Peritonitis Sepsis Death

No known genetic cause but increased risk has been observed in some studies in those with a positive family history

Most common acute surgical abdominal emergency Most common non-obstetric surgical emergency in pregnancy Most common between ages 10-20 yrs More common in males Lifetime risk is 8.6 % in males and 6.9 % in females Lifetime appendicectomy rate is 12 % in males and 23 % in females Perforation is found in 13-20 % Normal appendix is found in 15-40 % of patients who have an emergency appendectomy Misdiagnosed in 25-30 % children ( second most common cause of malpractice litigation against emergency physicians )
 Risk factors for appendicitis are
○ Age → most common 10-20 yrs
○ Male sex
○ frequent antibiotic use
○ Smoking ( incl exposure to passive smoking )
○ low fibre diet
○ less than 6 months of breast feeding

Diagnosis-Notoriously difficult to diagnose Classic clinical picture
○ anorexia
○ periumbilical pain followed by 
 RLQ pain
○ Vomiting
 Nausea and vomiting present in 75 %
Vomiting usually occurs once or twice Usually no significant changes in vital signs Fever – mild ( 1* or 1.8 *F rise ) Bowel sounds may be reduced on rt Duration of symptoms is less than 48 hrs in approximately 80 % of adults ( can be longer in elderly or in those with perforation )

Pain-Abdominal pain is the chief complain
○ tenderness on percussion at McBurneys pt ( 2/3rds of the way along a line drawn from umbilicus to the ASISpine )
○ guarding
○ rebound tenderness Migratory pain -> symptoms begin as peri-umbilical or epigastric pain migrating to the RLQ
Sensitivity and specificity of 80 %
Positive likelihood ratio of 3.18
Negative likelihood ratio of 0.5 Pain is worse with movement so patients
lie down
Flex their hips
draw their knees up
 Children – ask them to hop ( refusal indicates pain is worsened by hopping )
 Classical abdominal findings will be absent if appendix is in a atypical position
○ only 40 % of patients have the base of appendix within 3 cm of McBurney’s pt
○ 36 % have the base > 5 cm away – they can present with LLQ , Rt flank or back pain
 Peritoneal signs ( Rovsing’s , Psoas & Obturator ) are less commonly seen

Blood- elevated WCC , CRP , granulocyte count or proportion of polymorphonuclear leukocytes ( > 75 % ) Urine- pregnancy , infection , colic CT ( ideally with contrast ) is the most accurate examination for evaluating patients without a clear clinical diagnosis Scoring systems have been developed ( eg Alvarado score ) but in adults scoring systems have been inadequate as a single method Ultra-sound – limits radiation ( eg preferred in children ) MRI – in pregnancy results comparable following equivocal or inconclusive US

Medical emergency → needs immediate hospital admission Risk of complications increase with duration of symptoms Keep a very low threshold for admitting
○ Infants and young children
○ Elderly people
○ Pregnant women
○ If any signs of complications present It is unclear if antibiotics alone are a suitable treatment for non-complicated appendicitis ( in comparison to surgery )


  1.  Acute Appendicitis BMJ 2017 ; 357:j 1703
  2. Appendicitis CKS NHS February 2016
  3. e Medicine Appendicitis Sandy Craig et al January 2017
  4. GP Online Clinical Review : Acute Appendicitis Miss Sophie-Ann Welchman July 2011
  5. Review Article Vermiform Appendix and Acute Appendicitis Sanjay Kumar Bhasin, Arsad Bashir Khan, Vijay Kumar, Sanjay Sharma, Rakesh Saraf JK Science Vol 9 No 4 , October- December 2007
  6. CrackCast Show Notes Chapter 93- Appendicitis
  7. BMJ Best Practice Acute Appendicitis
  8. Clinical Policy : Critical Issues in the Evaluation and Management of Emergency Department Patients with Suspected Appendicitis Howell JM et al  2010 Jan;55(1):71-116. doi: 10.1016/j.annemergmed.2009.10.004
  9. American College of Radiology ACR Appropriateness Criteria® Right Lower Quadrant Pain-Suspected Appendicitis
  10. S.A. Kabir, S.I. Kabir, R. Sun, Sadaf Jafferbhoy, Ahmed Karim,
    How to diagnose an acutely inflamed appendix; a systematic review of the latest evidence,
    International Journal of Surgery, Volume 40, 2017, Pages 155-162, ISSN 1743-9191,
  11. Humes, D J, and J Simpson. “Acute appendicitis.” BMJ (Clinical research ed.) vol. 333,7567 (2006): 530-4. doi:10.1136/bmj.38940.664363.AE
  12. Humes, D J, and J Simpson. “Acute appendicitis.” BMJ (Clinical research ed.) vol. 333,7567 (2006): 530-4. doi:10.1136/bmj.38940.664363.AE
  13. Rasmussen T, Fonnes S, Rosenberg J. Long-Term Complications of Appendectomy: A Systematic Review. Scand J Surg. 2018;107(3):189-196. doi:10.1177/1457496918772379


Related Charts:

Add Your Comments

Your email address will not be published.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

A4 Medicine  - Search Less and Learn More

Welcome to the A4 medicine community where we are constantly working to provide exceptional educational material to primary health care professionals. Subscribe to our website for complete access to our A4 Charts. They are aesthetically designed charts that contain 300 (plus and adding) common and complex medical conditions with the all information required for primary care in one single page that can help you in consultation/practice and exam.

Additionally, you will get complete access for our Learn From Experts : A4 Webinar Series in which domain experts share the video explainer presentation on one medical condition in one hour for the primary care. And you will also get a hefty discount on our publications and upcoming digital products.

We are giving a lifetime flat 30% discount to our first thousand users, discount code already applied to checkout.