Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + • Abdominal pain• Anorexia, nausea, and vomiting• Localized right lower quadrant pain• Low-grade fever• Leukocytosis +++ Epidemiology + • 7% of people in Western countries have appendicitis at some time in their lives• 200,000 appendectomies for acute appendicitis are performed each year in the United States• Incidence in developing countries has been increasing in proportion to economic gains and changes in lifestyle• Major causes: Obstruction of the proximal lumen by fibrous bands, lymphoid hyperplasia, fecaliths, calculi, or parasites• Evidence of temporal and geographic clustering of cases has suggested a primary infectious etiology• Diagnosis is most difficult in the very young or old• Highest incidence of false-positives occur in women between the ages of 20 and 40, attributable to pelvic inflammatory disease (PID) and other gynecologic conditions +++ Symptoms and Signs + • Classically, abdominal pain develops prior to nausea and vomiting• Peri-umbilical abdominal pain initially, then localizes to the right lower quadrant• Right lower quadrant rebound or percussion tenderness (localized "peritoneal irritation")• Constipation and indigestion are frequent complaints• Patients complain of discomfort with movement, walking, or coughing• Low-grade fever (99 °F-101 °F) unless perforation has occurred +++ Laboratory Findings + • Mild leukocytosis (10,000-15,000) with left shift• Mild elevations in amylase• UA frequently will show a few WBC and RBCs on microscopic exam• Elevated C-reactive protein and ESR levels +++ Imaging Findings + • Plain films may show evidence of localized air fluid levels or localized ileus or increased soft-tissue density in the right lower quadrant -Less common findings include an appendiceal calculus, altered right psoas stripe, or an abnormal right flank stripe• US may demonstrate a dilated tubular structure in the right lower quadrant although this technique is user- and institutional-dependant and is less sensitive in adults than in children• Spiral CT (either abdominal/pelvic or a dedicated "appendiceal protocol") is the most sensitive and specific diagnostic radiographic test -An enlarged appendix with peri-appendiceal fat stranding is demonstrated in 90-95% of cases-CT scans are of greatest value in patients with atypical clinical presentation or laboratory findings + • Acute salpingitis• PID• Regional enteritis/complicated Crohn disease• Viral gastroenterologic infection• Mesenteric adenitis• Dysmenorrhea• Ovarian lesions• Urinary tract infections• Small bowel obstruction• Cecal volvulus• Incarcerated hernia• Mesenteric ischemia• Acute cholecystitis• Right-sided diverticulitis (true cecal or a redundant sigmoid that flops over into the right lower quadrant)• Complicated peptic ulcer disease (with enteric contents collecting in the right paracolic gutter)• Infarcted epiploic appendage +++ Rule Out + • Nonsurgical etiology of right lower quadrant abdominal pain-Acute salpingitis-Dysmenorrhea-Urinary tract infections-Viral gastroenterologic infection-Mesenteric adenitis-Others• Complicated appendicitis manifested by right lower quadrant abscess formation + ... Your Access profile is currently affiliated with '[InstitutionA]' and is in the process of switching affiliations to '[InstitutionB]'. Please click ‘Continue’ to continue the affiliation switch, otherwise click ‘Cancel’ to cancel signing in. Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Password? Forgot Username? Sign in via OpenAthens Sign in via Shibboleth You already have access! Please proceed to your institution's subscription. Create a free a profile for additional features.