History and exam
Key diagnostic factors
Constant mid-abdominal pain which later (1 to 12 hours) shifts to right lower quadrant. Usually worse on movement and coughing.
An 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.
A classic sign is right lower quadrant abdominal tenderness (McBurney sign). There may be localized rebound tenderness, especially if the appendix is anterior. Compressing the left lower quadrant may also elicit pain in the right lower quadrant (Rovsing sign). Pain may also be elicited 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).
Other diagnostic factors
May occur at any age but is most commonly seen in early teens to late 40s.
Nausea and vomiting are 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
Low-grade, usually 1.8°F (1°C) increase in body temperature.
Bowel sounds may be reduced, particularly on the right side compared with the left.
Tachycardia may be present, particularly in patients with perforation.[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
Nausea and vomiting are 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
Pressing the left side of the abdominal cavity elicits pain in right lower quadrant.
Extending the right thigh on left lateral position elicits pain in right lower quadrant.
Pain is elicited in the right lower quadrant of abdomen by internal rotation of the flexed right thigh.
Risk factors
Affects immunologic responses to certain microbial organisms. Children who received <6 months of breastfeeding had a higher incidence of acute appendicitis compared with those who received >6 months of breastfeeding.[15]Gomez-Alcala AV, Hurtado-Guzman A. Early breastfeed weaning as a risk factor for acute appendicitis in children [in Spanish]. Gac Med Mex. 2005 Nov-Dec;141(6):501-4.
http://www.ncbi.nlm.nih.gov/pubmed/16381505?tool=bestpractice.com
[16]Pisacane A, de Luca U, Impagliazzo N, et al. Breast feeding and acute appendicitis. BMJ. 1995 Apr 1;310(6983):836-7.
http://www.bmj.com/cgi/content/full/310/6983/836
http://www.ncbi.nlm.nih.gov/pubmed/7711621?tool=bestpractice.com
Known to cause constipation. Children with appendectomies have low fiber in their diet compared with controls.[6]Arnbjornsson E. Acute appendicitis and dietary fiber. Arch Surg. 1983 Jul;118(7):868-70.
http://www.ncbi.nlm.nih.gov/pubmed/6305309?tool=bestpractice.com
[17]Adamidis D, Roma-Giannikou E, Karamolegou K, et al. Fiber intake and childhood appendicitis. Int J Food Sci Nutr. 2000 May;51(3):153-7.
http://www.ncbi.nlm.nih.gov/pubmed/10945110?tool=bestpractice.com
However, this theory is controversial.[18]Naaeder SB, Archampong EQ. Acute appendicitis and dietary fibre intake. West Afr J Med. 1998 Oct-Dec;17(4):264-7.
http://www.ncbi.nlm.nih.gov/pubmed/9921094?tool=bestpractice.com
A higher incidence of acute appendicitis in Western society may be related to the living conditions and improved personal hygiene.[19]Barker DJ, Osmond C, Golding J, et al. Acute appendicitis and bathrooms in three samples of British children. Br Med J (Clin Res Ed). 1988 Apr 2;296(6627):956-8.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2545433/pdf/bmj00279-0012.pdf
http://www.ncbi.nlm.nih.gov/pubmed/3129107?tool=bestpractice.com
A balance of gastrointestinal microbial flora is important for prevention of infection, for digestion, and providing important nutrients.[20]Huis in 't Veld JH. Gastrointestinal flora and health in man and animal [in Dutch]. Tijdschr Diergeneeskd. 1991 Mar 1;116(5):232-9.
http://www.ncbi.nlm.nih.gov/pubmed/1901673?tool=bestpractice.com
Frequent use of antibiotics and improved hygienic conditions lead to decreased exposure and/or imbalance of gastrointestinal microbial flora that may eventually lead to a modified response to viral infection and thereby trigger appendicitis.[21]Walker AR, Segal I. What causes appendicitis? J Clin Gastroenterol. 1990 Apr;12(2):127-9.
http://www.ncbi.nlm.nih.gov/pubmed/2157745?tool=bestpractice.com
Children exposed to passive smoking have significantly increased incidence of acute appendicitis.[22]Montgomery SM, Pounder RE, Wakefield AJ. Smoking in adults and passive smoking in children are associated with acute appendicitis. Lancet. 1999 Jan 30;353(9150):379.
http://www.ncbi.nlm.nih.gov/pubmed/9950450?tool=bestpractice.com
There is also an increased incidence of acute appendicitis in adult patients who smoke compared with adults who never smoked.[22]Montgomery SM, Pounder RE, Wakefield AJ. Smoking in adults and passive smoking in children are associated with acute appendicitis. Lancet. 1999 Jan 30;353(9150):379.
http://www.ncbi.nlm.nih.gov/pubmed/9950450?tool=bestpractice.com
[23]Oldmeadow C, Wood I, Mengersen K, et al. Investigation of the relationship between smoking and appendicitis in Australian twins. Ann Epidemiol. 2008 Aug;18(8):631-6.
http://www.ncbi.nlm.nih.gov/pubmed/18652981?tool=bestpractice.com