Acute appendicitis: Difference between revisions

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(Created page with "Acute appendicitis refers to acute inflammation of the vermiform appendix and is a common cause of acute abdomen. Rapid management is important to prevent complications such as perforation of the appendix. The lifetime incidence of appendicitis is 9% for men and 7% for women. The peak incidence is in the second and third decades of life, but it may occur at any age. The incidence of acute appendicitis has been decreasing since the 1970s, for reasons not known. == Etiol...")
 
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Acute appendicitis refers to acute inflammation of the vermiform appendix and is a common cause of acute abdomen. Rapid management is important to prevent complications such as perforation of the appendix.
'''Acute appendicitis''' refers to acute inflammation of the vermiform appendix and is a common cause of [[acute abdomen]]. Rapid management is important to prevent complications such as perforation of the appendix.


The lifetime incidence of appendicitis is 9% for men and 7% for women. The peak incidence is in the second and third decades of life, but it may occur at any age. The incidence of acute appendicitis has been decreasing since the 1970s, for reasons not known.
The lifetime incidence of appendicitis is 9% for men and 7% for women. The peak incidence is in the second and third decades of life, but it may occur at any age. The incidence of acute appendicitis has been decreasing since the 1970s, for reasons not known.
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** Perforation -> localised periappendicular abscess or faecal peritonitis
** Perforation -> localised periappendicular abscess or faecal peritonitis


“Complicated” appendicitis refers to the presence of periappendicular infiltration, periappendicular abscess, perforation, or peritonitis.
“Complicated” appendicitis refers to the presence of periappendicular infiltration, periappendicular abscess, [[Gastrointestinal perforation|perforation]], or [[peritonitis]].


== Clinical features ==
== Clinical features ==
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Other possible symptoms include fever and abnormal bowel habits.
Other possible symptoms include fever and abnormal bowel habits.


Various physical signs may be positive in acute appendicitis, including McBurney point tenderness, Rovsing sign, psoas sign, and obturator sign (topic A25 in surgery). Because of the localised peritonitis over the appendix, peritonitis signs like guarding, rebound tenderness, and heel-drop test may be positive and elicit pain in the right lower quadrant.
Various physical signs may be positive in acute appendicitis, including McBurney point tenderness, [[Rovsing sign]], [[psoas sign]], and [[obturator sign]]. Because of the localised peritonitis over the appendix, peritonitis signs like guarding, rebound tenderness, and heel-drop test may be positive and elicit pain in the right lower quadrant.


Diffuse peritonitis may be a sign of perforated appendicitis. The longer the duration of the symptoms, the higher the risk that the appendix has ruptured. After 48h, 65% of appendixes haved perforated.
Diffuse peritonitic signs may be a sign of perforated appendicitis. The longer the duration of the symptoms, the higher the risk that the appendix has ruptured. After 48h, 65% of appendixes haved perforated. Following perforation, the symptoms usually alleviate temporarily, as the pressure is relieved, until the condition worsens again.


There is considerable anatomical variation in the location of the free end of the appendix, which will influence the site of pain and findings on physical examination. A retrocaecal appendix may not cause localised tenderness in the right lower quadrant (because localised peritonitis does not occur). A pelvic appendix may cause localised tenderness well below McBurney’s point.
There is considerable anatomical variation in the location of the free end of the appendix, which will influence the site of pain and findings on physical examination. A retrocaecal appendix may not cause localised tenderness in the right lower quadrant (because localised peritonitis does not occur). A pelvic appendix may cause localised tenderness well below McBurney’s point.


== Diagnosis and evaluation ==
== Diagnosis and evaluation ==
A normal WBC count is unlikely in the case of acute appendicitis, as leukocytosis is present in > 80% of cases. The higher the WBC count, the higher the chance for gangrenous or perforated appendicitis. <abbr>CRP</abbr> is also frequently elevated.
A normal [[WBC]] count is unlikely in the case of acute appendicitis, as leukocytosis is present in > 80% of cases. The higher the WBC count, the higher the chance for gangrenous or perforated appendicitis. <abbr>CRP</abbr> is also frequently elevated.


In some countries (like Norway), imaging is usually not performed if the clinical presentation is very suspicious for acute appendicitis. If imaging is to be performed, low-dose abdominal CT with contrast or abdominal ultrasound are the modalities of choice. These may reveal suspicious features such as thickening and enhancement of the appendiceal wall, and rule out other pathologies as well. Imaging will also reveal features of perforation if present, like faeces or air in the abdominal cavity.
In some countries (like Norway), imaging is usually not performed if the clinical presentation is very suspicious for acute appendicitis. If imaging is to be performed, low-dose abdominal [[CT]] with contrast or abdominal [[ultrasound]] are the modalities of choice. These may reveal suspicious features such as thickening and enhancement of the appendiceal wall, and rule out other pathologies as well. Imaging will also reveal features of perforation if present, like faeces or air in the abdominal cavity.


Only histology can confirm the diagnosis of appendicitis, although one can usually tell whether the appendix is inflamed or not during surgery.
Only histology can confirm the diagnosis of appendicitis, although one can usually tell whether the appendix is inflamed or not during surgery.