Acute appendicitis is the most common cause of abdominal pain among children and teenagers worldwide. They can be either acute or chronic. Acute appendicitis develops fast and can be removed using surgery. It can become severe, however, if not discovered and treated in time. Chronic appendicitis, on the other hand, develops slower and has less pronounced symptoms.
Acute appendicitis is caused by bacterial infections in the vermiform appendix, a tubular extension of the large intestine which functions as part of the digestive process. When the appendix is blocked by feces or it is squeezed by lymph nodes, it swells and usually doesn’t receive enough blood.
The diagnosis of acute appendicitis in the pregnant patient can be particularly challenging, as nausea, anorexia, and abdominal pain may be symptoms of both appendicitis and normal pregnancy. In addition, the gravid uterus can displace the abdominal viscera, shifting the location of the appendix from the right lower quadrant. Appendicitis affects 1 in every 1,400 pregnancies, an incidence similar to that of the nonpregnant female population.It can occur in any trimester, with perhaps a slight increase in frequency during the second trimester. Perforation is more common in the third trimester, however, and results from a longer duration from the onset of symptoms to operation. The differential diagnosis of appendicitis includes not only the conditions possible in nonpregnant women, but also certain conditions specific to pregnancy: ectopic pregnancy, chorioamnionitis, preterm labor, placental abruption, and round ligament pain.
Because many of its signs and symptoms are nonspecific, the differential diagnosis of acute appendicitis is extensive and includes virtually all possible abdominal sources of pain, as well as some nonabdominal sources (see table below). However, some diagnoses are more likely than others in certain patient groups. For instance, in young males with a suggestive history and physical examination, acute appendicitis is the most likely cause of right lower quadrant pain. Meckel’s diverticulitis causes similar symptoms, but is relatively uncommon. Gastroenteritis is considerably more common and should be expected when nausea and vomiting precede the abdominal pain, or when diarrhea is a prominent symptom. Crohn’s disease affecting the terminal ileum may resemble appendicitis in its initial presentation, but on further questioning, the patient typically describes a subacute course including fever, weight loss, and pain.
Laboratory studies can be helpful in the diagnosis of appendicitis, but no single test is definitive. A white blood cell count (WBC) is perhaps the most useful laboratory test. Typically, the WBC is slightly elevated in nonperforated appendicitis, but may be quite elevated in the presence of perforation. The clinician must remember, however, that the WBC can be normal in patients with acute appendicitis, particularly in early cases. Serial WBC measurements improve the diagnostic accuracy, with a rising value over time commonly seen in patients with appendicitis. Urinalysis is performed to diagnose other potential causes for abdominal pain, specifically urinary tract infection and ureteral stone. Significant hematuria with colicky abdominal pain suggests ureterolithiasis, and testing directed at this diagnosis is indicated. A urinary tract infection, on the other hand, is not uncommon in patients with appendicitis. Its presence does not exclude the diagnosis of acute appendicitis, but it should be identified and treated. Although pyuria suggests urinary tract infection, it is not uncommon for the urinalysis in a patient with appendicitis to show a few white blood cells solely due to inflammation of the ureter by the adjacent appendix.