Patients with acute abdominal pain of

unclear etiology who are discharged should be instructed

to be re-examined within 1 2-24 hours by a health care

provider if still having active pain.

SUGGESTED READING

Cartwright SL, Knudson MP. Evaluation of acute abdominal

pain in adults. Am Fam Physician. 2008;77:97 1-978.

Graff LG, Robinson D. Abdominal pain and emergency department evaluation. Emerg Med Clin North Am. 2001; 19:

1 23-136.

O'Brien MC. Acute abdominal pain. In: Tintinalli JE, Stapczynski

JS, Ma OJ, Cline DM, Cydulka, RK, Meckler GD. Tintinalli's

Emergency Medicine: A Comprehensive Study Guide. 7th ed.

New York, NY: McGraw-Hill, 20 1l, pp. 519-527.

Ragsdale L, Southerland L. Acute abdominal pain in the older

adult. Emerg Med Clin North Am. 201 1;29:429-448.

Appendicitis

Anitha E. Mathew, MD

Key Points

• The absence of leukocytosis or the presence of diarrhea

does not rule out append icitis.

• Appendicitis is a clinical diagnosis, with imaging aiding in

atypical presentations or cases of diagnostic uncertainty.

INTRODUCTION

The lifetime risk of developing acute appendicitis in the

United States is 12% for males and 25% for females.

Appendicitis is caused by luminal obstruction of the appendix, typically by a fecalith, and less frequently by lymphatic

tissue, gallstones, tumors, or parasites. Continued luminal

secretion results in increased intraluminal pressure and vascular insufficiency, leading to bacterial proliferation, inflammation, and ultimately perforation.

CLINICAL PRESENTATION

� History

One half of patients present to the emergency department

within 24 hours of symptom onset, and another one third

present within the following 24 hours. Early on, patients

complain of general malaise, indigestion, anorexia, or

bowel irregularity. The presence of diarrhea should not be

used to exclude appendicitis. The classic patient presentation begins with periumbilical abdominal pain followed by

nausea, with or without emesis, and low-grade fever, after

which the pain migrates to the right lower quadrant (RLQ)

(Table 27-1). Atypical presentations of appendicitis are

common. Perforation often results in sudden resolution of

pain and should be suspected in patients who present more

than 48 hours after symptom onset.

• Rapid diagnosis and early surgical intervention help to

avoid compl ications associated with rupture.

• Intravenous anti biotics should be administered if perfo ­

ration is likely or has occurred.

Table 27-1. Frequency of historical featu res

of appendicitis.

Feature Frequency

Abdominal pain 1 00%

Anorexia 92%

Nausea 78%

Vomiting 54%

Migration of pain 50%

Fever 20%

Diarrhea 1 5%

� Physical Examination

Patients should receive a complete physical examination, including a pelvic exam for any women of childbearing age. Vague periumbilical abdominal tenderness

is observed early in the disease and then migrates to the

McBurney point, located one-third of the distance

between the right anterior superior iliac spine and the

umbilicus. Rebound tenderness and involuntary guarding suggest peritonitis. Rovsing sign, or pain in the RLQ

with palpation of the left lower quadrant (LLQ), can

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