Classic appendicitis begins with visceral pain, localized to the periumbilical region. Nausea and vomiting occur soon after, triggered by the appendiceal distention. As the inflammation begins to irritate the parietal peritoneum adjacent to the appendix, somatic pain fibers are activated, and the pain localizes to the right lower quadrant. Examination of the patient reveals a tender right lower quadrant. Voluntary guarding is present initially, progressing to rigidity, then to rebound tenderness with rupture and peritonitis. These classic findings may not be present, especially in young children or if the appendix is retrocecal, covered by omentum, or in another unusual location. Clinical prediction rules have been developed for the diagnosis of appendicitis. The Alvarado/MANTRELS rule is scored by 1 point for each of the following: migration of pain to the right lower quadrant, anorexia, nausea/vomiting, rebound pain, temperature of at least 37.3°C, and WBC shift to greater than 75% neutrophils; 2 points are given for each of tenderness in the right lower quadrant and leukocytosis greater than 10,000/μL. Children with a score of 4 or less are unlikely to have appendicitis; a score of 7 or greater increases the likelihood that the patient has appendicitis. When classic history and physical examination findings are present, the patient is taken to the operating room. When doubt exists, imaging is helpful to rule out complications (right lower quadrant abscess, liver disease) and other disorders, such as mesenteric adenitis and ovarian or fallopian tube disorders. If the evaluation is negative and some doubt remains, the child should be admitted to the hospital for close observation and serial examinations.
The history and examination are often enough to make the diagnosis, but laboratory and imaging studies are helpful when the diagnosis is uncertain (Table 129-3). A WBC count greater than 10,000/mm3 is found in 89% of patients with appendicitis and 93% with perforated appendicitis. This criterion is met by 62% of abdominal pain patients without appendicitis. Urinalysis is done to rule out urinary tract infection, and x-rays of the chest or the kidney, ureter, and bladder (KUB) rule
CBC with differential Urinalysis Amylase and lipase ALT, AST, GGT Flat and upright abdominal radiographs (KUB)
Abdominal ultrasound CT scan of abdomen
ALT, Alanine aminotransferase; AST, aspartate aminotransferase; CBC, complete blood count; CT, computed tomography; GGT, γ-glutamyltransferase; KUB, kidney, ureter, bladder. *Perform when diagnosis remains in doubt.
out lower lobe pneumonia masquerading as abdominal pain. Amylase, lipase, and liver enzymes are done to look for pancreatic or liver and gallbladder disease. The plain abdominal x-ray may reveal a calcified fecalith, which strongly suggests the diagnosis. When these studies are inconclusive, imaging is indicated with an abdominal ultrasound or CT scan, which may reveal the presence of an enlarged, thick-walled appendix with surrounding fluid. A diameter of more than 6 mm is considered diagnostic.
Treatment of appendicitis is surgical. Simple appendectomy iscurative if performed before perforation. With perforation, a course of postoperative IV antibiotics is required. Broad-spectrumcoverage is necessary to cover the mixed bowel flora.