Appendicitis - Quick Consult
Last Updated / Reviewed: 4/5/2021

Key History
Key Physical Exam
Differential Diagnosis
Diagnostic Testing
Clinical Risk and Safety Pearls
Pregnancy and Appendicitis
ACEP Policy 

Key History

  • Periumbilical pain localizes to RLQ in 70% of cases
  • Anorexia – 80%
  • Nausea/Vomiting
  • Abdominal pain develops before nausea and vomiting
  • Constipation or diarrhea may occur
  • Low-grade temperature is common, but fever usually appears late
  • If fever higher than 39.4ºC (103ºF) consider perforated appendix
  • Non-specific complaints, such as not feeling well, indigestion, flatulence are common
  • Urinary frequency, dysuria, tenesmus, or diarrhea common with appendix in the pelvic position
  • Abdominal dull ache can be associated with retro-cecal appendix
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Key Physical Exam

  • Tender abdomen – especially in the RLQ
  • Tenderness at McBurney’s point (point is 1/3 of the distance on a line starting from the anterior superior iliac crest to the umbilicus)
  • Rebound tenderness suggests perforation with peritonitis
  • Psoas sign - pain in RLQ with extension of the right hip
  • Obturator sign - pain in RLQ with internal rotation of hip
  • Rovsing’s sign - pain in RLQ with palpation of LLQ
  • May have tenderness during rectal and pelvic exam
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Differential Diagnosis

Gastrointestinal Genitourinary Gynecological
  • Appendiceal neoplasm
  • Appendicitis
  • Cecal diverticulitis
  • Cholecystitis
  • Cholelithiasis
  • Constipation
  • Crohn's disease
  • Diverticulitis
  • Gastroenteritis
  • GERD
  • GI Bleed
  • Hepatitis
  • Intestinal obstruction
  • Intussusception
  • Irritable bowel syndrome
  • Meckel’s diverticulitis
  • Mesenteric adenitis
  • Omental torsion
  • Pancreatitis
  • Peptic ulcer disease
  • Perforated ulcer
  • Peritonitis
  • Small bowel obstruction
  • Typhlitis
  • Dysmenorrhea
  • Ectopic pregnancy
  • Endometriosis
  • Menorrhagia
  • Ovarian torsion
  • PID
  • Ruptured cyst
  • Tubal ovarian abscess
  • Twisted ovarian cyst
Cardiovascular Other
  • Diabetes ketoacidosis
  • Hemolytic uremic syndromes
  • Herpes zoster
  • Henoch schönlein purpura
  • Pneumonia
  • Sickle cell crisis
  • Streptococcal pharyngitis

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Diagnostic Testing

Text / literature information and recommendations include:
  1. Labs:
    • WBC count - May be elevated or normal; a higher white count is associated with perforation
    • C-reactive protein (CRP)
    • Urinalysis may show hematuria or pyuria – found in up to 1/3 of patients with appendicitis
    • B-hCG mandatory to rule out an ectopic pregnancy in females of childbearing age
  2. Imaging - Obtain early surgical consultation before imaging in straightforward cases of suspected appendicitis in adults. Imaging is not universally necessary but may be of benefit in certain populations.
    • KUB. Plain radiography is generally not helpful. Findings are typically nonspecific. An appendicolith may be visualized in up to 50% of children with appendicitis.
    • Graded compression ultrasound. Ultrasound should be the initial imaging modality of choice in both pregnant females and children. It can likewise be considered in young, nonobese adults (typical findings in appendicitis are a thickened, noncompressible appendix > 6 mm in diameter. A meta-analysis by Doria et al. lists the overall sensitivity of ultrasound as 88% and 83% and its specificity as 94% and 93% for children and adults, respectively.
    • Noncontrast CT. Unenhanced, noncontrast abdominopelvic CT should be considered an acceptable imaging modality in the workup of acute appendicitis. There is controversy over the use of IV and oral contrast. Many centers continue to use one or both. CT demonstrates higher diagnostic accuracy thea ultrasound or MRI. The disadvantage is the exposure to ionizing radiation.
    • MRI. MRI may be considered as another reliable imaging technology in the evaluation of acute appendicitis, particularly in pregnant women.
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Clinical Risk and Safety Pearls

  • Abdominal pain usually occurs before nausea and vomiting, unlike gastroenteritis where nausea and vomiting usually occur first.
  • Serial evaluations over several hours may improve diagnostic accuracy in patients with an atypical presentation.
  • The presence of appendicitis is not always apparent on the initial visit. Evaluate and re-evaluate. Document carefully. Demonstrate high quality care and that the diagnosis was simply not apparent during your evaluation.
  • The urinalysis may show hematuria or pyuria, which is present in up to 1/3 of patients with appendicitis.
  • Order a B-HCG to rule out an ectopic pregnancy in females of childbearing age.
  • Taking a history of symptoms immediately prior to onset of pain is helpful in determining diagnosis.
  • Early in the presentation the abdominal exam may be unremarkable.
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Pregnancy and Appendicitis

See separate topic Appendicitis in pregnancy

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Common text / literature recommendations include:
  • Surgery – Surgery remains the most common approach to treatment, with appendectomy still considered the gold standard for uncomplicated appendicitis. Antibiotic therapy can be successful in selected patients with uncomplicated appendicitis who wish to avoid surgery and accept up to 38% risk of recurrence.
  • IV hydration
  • Pain medication
  • A single dose of cefoxitin (2 g IV) or cefotetan (2 g IV) or alternatively cefazolin (2 g if < 120 kg, or 3 g if ≥ 120 kg IV) plus metronidazole (500 mg IV). If patient is allergic to penicillins or cephalosporins, clindamycin plus one of the following: ciprofloxacin, levofloxacin, gentamicin, or aztreonam.
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ACEP Policy

The most recent guidelines from the American College of Emergency Physicians were published in 2010. This was a clinical policy with a focus on 3 or 4 critical issues related to abdominal pain and appendicitis. Subsequent evidence has rendered most of the issues moot, so they will not be reproduced here. There are no subsequent updates or publications on the subject.

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  1. Abbasi N, Patenaude V, Abenhaim HA. Management and outcomes of acute appendicitis in pregnancy-population-based study of over 7000 cases. BJOG. 2014; 121:1509.
  2. Dai L, Shuai J. Laparoscopic versus open appendectomy in adults and children: A meta-analysis of randomized controlled trials. United European Gastroenterol J. 2017;5(4):542-553.
  3. Di Saverio S, Birindelli A, Kelly MD, et al. WSES Jerusalem guidelines for diagnosis and treatment of acute appendicitis. World J Emerg Surg. 2016;11:34.
  4. Flum, DR, McClure, TD, Morris, A, Koepsell, T. Misdiagnosis of appendicitis and the use of diagnostic imaging. J Am Coll Surg 2005; 201:933.
  5. Gorter RR, Eker HH, Gorder-Starn MA, et al. Diagnosis and management of acute appendicitis. EAES consensus development conference 2015. Surg Endosc. 2016;30(11):4668-4690.
  6. Harnoss JC, Zelienka I, Probst P, et al. Antibiotics versus surgical therapy for uncomplicated appendicitis: Systematic review and meta-analysis of controlled trials (PROSPERO 2015). Ann Surg. 2017;265(5):889-900.
  7. Hlibczuk V, Dattaro J, Jin Z, et al. Diagnostic accuracy of noncontrast computed tomography for appendicitis in adults: a systematic review. Ann Emerg Med. 55: 51, 2010.
  8. House JB, Bourne CL, Seymour HM, Brewer KL. Location of the appendix in the gravid patient. J Emerg Med. 2014; 46:741.
  9. Howell J, Eddy O, Lukens T, et al. Clinical policy: critical issues in the evaluation and management of emergency department patients with suspected appendicitis. Ann Emerg Med. 55: 71, 2010. [PMID: 20116016]
  10. Melnick ER, Melnick JR, Nelson BP. Pelvic ultrasound in acute appendicitis. J Emerg Med. 38: 240, 2010. [PMID: 18571366]
  11. Pates JA, Avendanio TC, Zaretsky MV, et al. The appendix in pregnancy: confirming historical observations with a contemporary modality. Obstet Gynecol. 2009; 114:805.
  12. Salminen P, Paajanen H, Rautio T, et al. Antibiotic therapy vs appendectomy for treatment of uncomplicated acute appendicitis: the APPAC randomized clinical trial. JAMA. 2015;313(23):2340-2348.
  13. Sartelli M, Baiocchi GL, Di Saverio S. Prospective Observational Study on acute Appendicitis Worldwide (POSAW). World J Emerg Surg. 2018;13:19.
  14. Sartelli M, Viale P, Catena F, et al. 2013 WSES guidelines for management of intra-abdominal infections. World J Emerg Surg. 2013;8(1):3.
  15. Talan DA, Saltzman DJ, Mower WR, et al. Antibiotics-first versus surgery for appendicitis: a US pilot randomized controlled trial allowing outpatient antibiotic management. Ann Emerg Med. Published online ahead of print Dec. 11, 2016. [PMID: 19733421]

This is intended solely as reference material and is not a recommendation for any specific patient. The practitioner must rely upon his or her own professional judgment and medical decision-making to determine whether it is relevant in a particular case. Materials are derived from medical and nursing texts, medical literature and national guidelines and should not be considered complete or authoritative. Users must rely on specific patient presentation, experience and judgment when utilizing any of the information contained herein relative to an actual patient.

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