A sudden inflammation of the appendix. The appendix is a narrow, small, finger-shaped tube that branches off the large intestine.
Causes, incidence, and risk factors
Appendicitis is one of the most common causes of emergency abdominal surgery in children. Approximately 4 appendectomies per 1000 children under age 18 are done annually in the United States. It is more common in males than females and incidence peaks in the late teens and early twenties. Appendicitis is uncommon under age two, but it can occur. Appendicitis generally follows obstruction of the appendix by feces (fecalith), a foreign body, or rarely, a tumor . Symptoms of appendicitis in young children are seldom classic so diagnosis is commonly delayed and perforation more likely. Older children and adolescents usually have a more typical presentation. Classic presentation of appendicitis begins with crampy or "colicky" pain around the navel (periumbilical). There is usually a marked loss or total absence of appetite ( anorexia ), often associated with nausea, and occasionally, vomiting. As the inflammation in the appendix increases, the pain tends to move downward and to the right (right lower quadrant, RLQ) and localizes directly above the position of the appendix at a point called " McBurney's Point " (If a line is drawn from the navel to the prominence on the right pelvic bone (right superior iliac crest) and divided into thirds, McBurney's Point is 2/3 away from the navel). The child may be quite tender when the abdomen is pressed at McBurney's Point. When the abdomen is depressed, held momentarily, and then rapidly released, the child may experience a momentary increase in pain (rebound tenderness). This finding suggests inflammation has spread to the peritoneum. If the appendix ruptures, the pain may disappear for a short period and the child may feel suddenly better. However, within a short period peritonitis sets in, the pain returns, and the child becomes progressively more ill. At this time the abdomen may become rigid and extremely tender.
Signs and tests
When the abdomen is gently pressed in the painful area, and then the pressure is suddenly released, the pain increases (rebound tenderness). Touching the abdomen may cause spasm of the abdominal muscles if peritonitis is present. Rectal examination causes pain that is localized on the right side. The Psoas sign is positive -- the person is placed on his (her) back in a supine position and the right leg is extended straight up, eliciting pain in the RLQ. A Rovsing's sign may also be seen: palpation in the LLQ leads to pain in the RLQ. The Obturator sign may also be positive: while lying flat, the knee and hip are flexed, and then the leg is rotated inward and outward, eliciting pain. Appendicitis may be strongly suspected based on the following tests:
A CBC often shows an increased white blood cell count .
An abdominal sonography may show appendicitis.
An abdominal CT scan may show signs of appendicitis.
The surgeon may confirm the diagnosis during an exploratory laparotomy , usually through a small RLQ incision. It is important to realize that not all surgical explorations for appendicitis reveal an abnormal appendix. Approximately 10-15% of operations for suspected appendicitis reveal either no obvious abnormality, or a disease process other than appendicitis. This relatively high rate of negative appendectomies" is tolerated because the consequences of missed appendicitis in patients with abdominal pain who are not taken for operation promptly can be severe and sometimes, life-threatening. If an operation for suspected appendicitis reveals a normal appendix, the surgeon will remove the appendix anyway, and then explore the rest of the abdomen for other possible causes of pain. In some cases, this may require extension of the surgical incision.
Treatment
For uncomplicated appendicitis, surgery ( appendectomy ) is performed as soon as possible after the diagnosis is made based on clinical findings (exam laboratory tests). Little preparation is required. If an abscess is suspected, the surgery may be delayed until antibiotic therapy has reduced the infection. In cases where the diagnosis is uncertain, an ultrasound or CT scan of the abdomen may be obtained.
Expectations (prognosis)
Early surgery has a death rate of less than 0.5%.
Calling your health care provider
Call your health care provider if right-lower quadrant abdominal pain or other symptoms suggestive of appendicitis develop.