History and physical examination form the initial approach in the evaluation of a patient with possible appendicitis.[2]Itskowitz MS, Jones SM. Appendicitis. Emerg Med. 2004;36:10-5. It is routine practice in the US to request a computed tomography (CT) scan for patients presenting to the emergency room with features of acute appendicitis.[24]Bendeck SE, Nino-Murcia M, Berry GJ, et al. Imaging for suspected appendicitis: negative appendectomy and perforation rates. Radiology. 2002 Oct;225(1):131-6.
http://www.ncbi.nlm.nih.gov/pubmed/12354996?tool=bestpractice.com
Validated clinical decision tools such as the Alvarado score demonstrate high sensitivities and are useful for excluding appendicitis, but lack specificity.[25]Alvarado A. A practical score for the early diagnosis of acute appendicitis. Ann Emerg Med. 1986 May;15(5):557-64.
http://www.ncbi.nlm.nih.gov/pubmed/3963537?tool=bestpractice.com
[26]Kularatna M, Lauti M, Haran C, et al. Clinical prediction rules for appendicitis in adults: which is best? World J Surg. 2017 Jul;41(7):1769-81.
http://www.ncbi.nlm.nih.gov/pubmed/28258458?tool=bestpractice.com
[27]Frountzas M, Stergios K, Kopsini D, et al. Alvarado or RIPASA score for diagnosis of acute appendicitis? A meta-analysis of randomized trials. Int J Surg. 2018 Aug;56:307-14.
http://www.ncbi.nlm.nih.gov/pubmed/30017607?tool=bestpractice.com
Ultrasound or magnetic resonance imaging (MRI) of the abdomen are recommended if the patient is pregnant.[28]American College of Radiology. ACR appropriateness criteria: right lower quadrant pain - suspected appendicitis. 2018 [internet publication].
https://www.acr.org/Quality-Safety/Appropriateness-Criteria
[29]Di Saverio S, Birindelli A, Kelly MD, et al. WSES Jerusalem guidelines for diagnosis and treatment of acute appendicitis. World J Emerg Surg. 2016 Jul 18;11:34.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4949879/
http://www.ncbi.nlm.nih.gov/pubmed/27437029?tool=bestpractice.com
Women of childbearing age should have a pelvic examination to rule out other pelvic pathology.[30]Basaran A, Basaran M. Diagnosis of acute appendicitis during pregnancy: a systematic review. Obstet Gynecol Surv. 2009 Jul;64(7):481-8; quiz 499.
http://www.ncbi.nlm.nih.gov/pubmed/19545456?tool=bestpractice.com
History
Abdominal pain is the main presenting complaint. Pain typically starts at mid-abdominal region and later (1 to 12 hours) shifts to the right lower quadrant. Pain is usually constant in nature and with intermittent abdominal cramps and is usually worse on movement and coughing.
Location of the pain may vary depending upon the position of the appendix:
Retrocecal appendix may cause flank or back pain
Retroileal appendix may cause testicular pain due to irritation of the spermatic artery or ureter
Pelvic appendix may cause suprapubic pain
A long appendix with tip inflammation in the left lower quadrant may cause pain to that region.
Anorexia is another important symptom almost always associated with acute appendicitis.[31]Hardin DM. Acute appendicitis: review and update. Am Fam Physician. 1999 Nov 1;60(7):2027-34.
http://www.ncbi.nlm.nih.gov/pubmed/10569505?tool=bestpractice.com
Without anorexia the diagnosis of acute appendicitis is in question. Nausea and vomiting are also present in 75% of patients.[31]Hardin DM. Acute appendicitis: review and update. Am Fam Physician. 1999 Nov 1;60(7):2027-34.
http://www.ncbi.nlm.nih.gov/pubmed/10569505?tool=bestpractice.com
Absolute constipation is a late feature.
The sequence of presentation in 95% of patients with acute appendicitis usually starts with anorexia, followed by abdominal pain and then vomiting.[31]Hardin DM. Acute appendicitis: review and update. Am Fam Physician. 1999 Nov 1;60(7):2027-34.
http://www.ncbi.nlm.nih.gov/pubmed/10569505?tool=bestpractice.com
However, in pregnant patients, the only features shown to be significantly associated with a diagnosis of appendicitis are nausea, vomiting, and local peritonitis.[32]Brown JJ, Wilson C, Coleman S, Joypaul BV. Appendicitis in pregnancy: an ongoing diagnostic dilemma. Colorectal Dis. 2009 Feb;11(2):116-22.
http://www.ncbi.nlm.nih.gov/pubmed/18513191?tool=bestpractice.com
Complicated appendicitis (perforation or intra-abdominal abscess) is more likely the greater the duration of symptoms and in older patients (>50 years).[33]Temple CL, Shirley AH, Temple WJ. The natural history of appendicitis in adults. A prospective study. Ann Surg. 1995 Mar;221(3):278-81.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1234570/pdf/annsurg00049-0078.pdf
http://www.ncbi.nlm.nih.gov/pubmed/7717781?tool=bestpractice.com
[34]Franz MG, Norman J, Fabri PJ. Increased morbidity of appendicitis with advancing age. Am Surg. 1995 Jan;61(1):40-4.
http://www.ncbi.nlm.nih.gov/pubmed/7832380?tool=bestpractice.com
Physical exam
Usually, there are no significant changes in vital signs. Body temperature may be slightly increased (by an average of 1.8°F [1°C]). In patients presenting with a high-grade fever, another diagnosis should be considered.[35]Berry J, Malt RA. Appendicitis near its centenary. Ann Surg. 1984 Nov;200(5):567-75.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1250537/pdf/annsurg00117-0017.pdf
http://www.ncbi.nlm.nih.gov/pubmed/6385879?tool=bestpractice.com
Tachycardia may also be present.[36]Humes DJ, Simpson J. Acute appendicitis. BMJ. 2006 Sep 9;333(7567):530-4.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1562475/
http://www.ncbi.nlm.nih.gov/pubmed/16960208?tool=bestpractice.com
A classic sign is right lower quadrant abdominal tenderness (McBurney sign) and localized rebound tenderness, if appendix is anterior. There may also be pain in the right lower quadrant after compressing the left lower quadrant (Rovsing sign).
Pain may be elicited in the right lower quadrant with the patient lying on their left side and slowly extending the right thigh to cause a stretch in the iliopsoas muscle (psoas sign) or by internal rotation of the flexed right thigh (obturator sign).
Bowel sounds may be reduced, particularly on the right side compared with on the left.
Classical abdominal findings may not be present if the appendix is in an atypical position.
Patients with perforation may present acutely ill with hypotension, tachycardia, and a tense, distended abdomen with generalized guarding and absent bowel sounds.
A palpable mass may be felt with appendiceal perforation that has been contained by the omentum, resulting in a periappendiceal abscess.
Investigation
All patients with abdominal discomfort should have a complete blood count taken. Mild leukocytosis (10,000 to 18,000/microliter) with increased neutrophils is usually present.
Some form of imaging is usually warranted. Most nonpregnant patients presenting to the emergency room with abdominal pain suggestive of appendicitis will have a CT scan of the abdomen and pelvis.[28]American College of Radiology. ACR appropriateness criteria: right lower quadrant pain - suspected appendicitis. 2018 [internet publication].
https://www.acr.org/Quality-Safety/Appropriateness-Criteria
[29]Di Saverio S, Birindelli A, Kelly MD, et al. WSES Jerusalem guidelines for diagnosis and treatment of acute appendicitis. World J Emerg Surg. 2016 Jul 18;11:34.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4949879/
http://www.ncbi.nlm.nih.gov/pubmed/27437029?tool=bestpractice.com
Preoperative imaging with a CT scan of the abdomen (ultrasound or MRI for pregnant women) now forms the usual standard of care. Women and children, in particular, may benefit from preoperative imaging.[24]Bendeck SE, Nino-Murcia M, Berry GJ, et al. Imaging for suspected appendicitis: negative appendectomy and perforation rates. Radiology. 2002 Oct;225(1):131-6.
http://www.ncbi.nlm.nih.gov/pubmed/12354996?tool=bestpractice.com
[37]Bachur RG, Callahan MJ, Monuteaux MC, et al. Integration of ultrasound findings and a clinical score in the diagnostic evaluation of pediatric appendicitis. J Pediatr. 2015 May;166(5):1134-9.
http://www.ncbi.nlm.nih.gov/pubmed/25708690?tool=bestpractice.com
[38]Benabbas R, Hanna M, Shah J, et al. Diagnostic accuracy of history, physical examination, laboratory tests, and point-of-care ultrasound for pediatric acute appendicitis in the emergency department: a systematic review and meta-analysis. Acad Emerg Med. 2017 May;24(5):523-51.
https://onlinelibrary.wiley.com/doi/full/10.1111/acem.13181
http://www.ncbi.nlm.nih.gov/pubmed/28214369?tool=bestpractice.com
Choice of imaging modality
Although CT scan has greater sensitivity and specificity than ultrasound in diagnosing appendicitis, the latter is readily available, rapid, and able to be performed at the bedside.[39]Fox JC, Solley M, Zlidenny A, et al. Bedside ultrasound for appendicitis. Acad Emerg Med. 2005;12:76.[40]Terasawa T, Blackmore CC, Bent S, et al. Systematic review: computed tomography and ultrasonography to detect acute appendicitis in adults and adolescents. Ann Intern Med. 2004 Oct 5;141(7):537-46.
http://www.ncbi.nlm.nih.gov/pubmed/15466771?tool=bestpractice.com
[41]Dahabreh IJ, Adam GP, Halladay CW, et al. Diagnosis of right lower quadrant pain and suspected acute appendicitis. In: Agency for Healthcare Research and Quality (US). AHRQ Comparative effectiveness reviews report no. 15(16)-EHC025-EF. 2015. Rockville, MD: Agency for Healthcare Research and Quality (US).
https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0086388/
http://www.ncbi.nlm.nih.gov/pubmed/27054223?tool=bestpractice.com
[39]Fox JC, Solley M, Zlidenny A, et al. Bedside ultrasound for appendicitis. Acad Emerg Med. 2005;12:76. In children, ultrasound may be preferred over CT scan in order to limit radiation exposure. There is evidence to suggest enhanced sensitivity and specificity of ultrasound in children compared with adults.[37]Bachur RG, Callahan MJ, Monuteaux MC, et al. Integration of ultrasound findings and a clinical score in the diagnostic evaluation of pediatric appendicitis. J Pediatr. 2015 May;166(5):1134-9.
http://www.ncbi.nlm.nih.gov/pubmed/25708690?tool=bestpractice.com
[42]Eng KA, Abadeh A, Ligocki C, et al. Acute appendicitis: a meta-analysis of the diagnostic accuracy of US, CT, and MRI as second-line imaging tests after an initial US. Radiology. 2018 Sep;288(3):717-27.
https://pubs.rsna.org/doi/10.1148/radiol.2018180318?url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org&rfr_dat=cr_pub%3Dpubmed&
http://www.ncbi.nlm.nih.gov/pubmed/29916776?tool=bestpractice.com
[43]Zhang H, Liao M, Chen J, et al. Ultrasound, computed tomography or magnetic resonance imaging - which is preferred for acute appendicitis in children? A Meta-analysis. Pediatr Radiol. 2017 Feb;47(2):186-96.
http://www.ncbi.nlm.nih.gov/pubmed/27815615?tool=bestpractice.com
If, on ultrasound, a normal appendix is visualized in its full length, then acute appendicitis can be excluded. However, this is rarely the case, and the greatest utility for ultrasound is to detect an alternative cause of abdominal pain that excludes appendicitis.[44]Puylaert JB. Imaging and intervention in patients with acute right lower quadrant disease. Baillieres Clin Gastroenterol. 1995 Mar;9(1):37-51.
http://www.ncbi.nlm.nih.gov/pubmed/7772814?tool=bestpractice.com
Appendiceal CT scan is increasingly used as the initial diagnostic test for acute appendicitis, and it is routine practice in the US to request a CT for patients presenting to the emergency room with features of acute appendicitis.[24]Bendeck SE, Nino-Murcia M, Berry GJ, et al. Imaging for suspected appendicitis: negative appendectomy and perforation rates. Radiology. 2002 Oct;225(1):131-6.
http://www.ncbi.nlm.nih.gov/pubmed/12354996?tool=bestpractice.com
A CT is also indicated in atypical presentations.[28]American College of Radiology. ACR appropriateness criteria: right lower quadrant pain - suspected appendicitis. 2018 [internet publication].
https://www.acr.org/Quality-Safety/Appropriateness-Criteria
[45]American College of Radiology. ACR Appropriateness Criteria: acute nonlocalized abdominal pain. 2018 [internet publication].
https://acsearch.acr.org/docs/69467/Narrative/
However, delayed surgery subsequent to CT scan for presumed appendicitis is associated with an increased rate of appendiceal perforation.[46]Musunuru S, Chen H, Rikkers LF, et al. Computed tomography in the diagnosis of acute appendicitis: definitive or detrimental? J Gastrointest Surg. 2007 Nov;11(11):1417-21; discussion 1421-2.
http://www.ncbi.nlm.nih.gov/pubmed/17701439?tool=bestpractice.com
Intravenous contrast-enhanced CT scan with or without oral contrast has up to 100% sensitivity compared with 92% sensitivity in nonintravenous contrast-enhanced CT scan.[47]Chiu YH, Chen JD, Wang SH, et al. Whether intravenous contrast is necessary for CT diagnosis of acute appendicitis in adult ED patients? Acad Radiol. 2013 Jan;20(1):73-8.
https://www.academicradiology.org/article/S1076-6332(12)00385-6/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/22951113?tool=bestpractice.com
[48]Hlibczuk V, Dattaro JA, Jin Z, et al. Diagnostic accuracy of noncontrast computed tomography for appendicitis in adults: a systematic review. Ann Emerg Med. 2010 Jan;55(1):51-9.e1.
http://www.ncbi.nlm.nih.gov/pubmed/19733421?tool=bestpractice.com
[Figure caption and citation for the preceding image starts]: CT abdomen - thickened appendix.Nasim Ahmed, MBBS, FACS; used with permission [Citation ends].
In pregnant women presenting with features of appendicitis, an abdominal sonogram should be performed to identify the appendix. If the sonogram examination is inconclusive, an abdominal MRI (particularly in early pregnancy) may be appropriate.[30]Basaran A, Basaran M. Diagnosis of acute appendicitis during pregnancy: a systematic review. Obstet Gynecol Surv. 2009 Jul;64(7):481-8; quiz 499.
http://www.ncbi.nlm.nih.gov/pubmed/19545456?tool=bestpractice.com
[28]American College of Radiology. ACR appropriateness criteria: right lower quadrant pain - suspected appendicitis. 2018 [internet publication].
https://www.acr.org/Quality-Safety/Appropriateness-Criteria