Appendicitis is inflammation and infection of the appendix.
The appendix is a small finger-length portion of intestine that does not clearly have any essential bodily function (see Digestive System). However, appendicitis is a medical emergency that requires surgery. This disorder is rare in children younger than 1 year but becomes more common as children grow older and is most common among adolescents and adults in their 20s.
Appendicitis seems to develop when the appendix becomes blocked either by hard fecal material (fecalith) or swollen lymph nodes in the intestine, which can occur with various infections. In either case, the appendix swells, and bacteria in it grow. Rarely, foreign bodies and worms can also cause appendicitis. If appendicitis is unrecognized or untreated, the appendix can rupture, creating a pocket of infection outside the intestine (abscess) or spilling contents of the intestines into the abdominal cavity, causing a serious infection (peritonitis). In about 25% of children with appendicitis, the appendix has already ruptured by the time they arrive at the hospital.
Symptoms and Diagnosis
Appendicitis almost always causes pain. The pain may start in the middle of the abdomen, near the navel, and move to the lower right area of the abdomen. Pain, particularly in infants and children, may be widespread rather than confined to the right lower portion of the abdomen. Younger children may be less able to identify a specific location for the pain. After the pain has begun, many children begin vomiting and do not want to eat. A low-grade fever (100 to 101° F [37.7 to 38.3° C]) is a common symptom. This pattern is different from that in children who have viral gastroenteritis, in whom vomiting typically occurs first, and pain and diarrhea develop later.
The diagnosis of appendicitis in children can be challenging for many reasons. Many disorders can cause similar symptoms, including viral gastroenteritis, Meckel diverticulum, intussusception, and Crohn disease. Often, children do not have typical symptoms and physical examination findings, particularly when the appendix is not in its usual position in the right lower part of the abdomen.
Doctors who suspect appendicitis usually give fluids and antibiotics by vein while waiting for results of blood tests and imaging tests. Most often doctors do ultrasonography, which does not expose the child to radiation. If ultrasonography is inadequate, doctors may do computed tomography (CT) or laparoscopy (see Diagnosis of Digestive Disorders: Laparoscopy) to see inside the abdomen. Repeated physical examinations, especially in children whose pain is not typical of appendicitis, may help doctors decide whether appendicitis is present.
The best treatment for appendicitis is surgical removal of the inflamed appendix (appendectomy). Appendectomy is fairly simple and safe, requiring a hospital stay of 2 to 3 days in uncomplicated cases. If the appendix has ruptured, the doctor removes it and may wash out the abdomen with fluid, give antibiotics for several days, and watch for complications, such as infection and bowel blockage. About 10 to 20% of the time, surgeons discover a normal appendix while performing an appendectomy. This finding is not considered a medical error because the consequences of delaying surgery when appendicitis is suspected are serious. When the appendix is found to be normal, the surgeon looks within the abdomen for another cause of the pain. The doctor usually removes the normal appendix so that the child never develops appendicitis. Without surgery or antibiotics, more than 50% of people with appendicitis die.
Last full review/revision November 2012 by William J. Cochran, MD