Acute appendicitis

Alternative names:

appendicitis

Definition:

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 anually in the United States (Note: appendicitis is not diagnosed in 100% of appendectomies). 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 can occur. Appendicitis generally follows obstruction of the appendix by feces (fecalith), a foreign body, or tumor.

Symptoms of appendicitis in young children are seldom classic so diagnosis is commonly delayed and perforation more likely. Older children and adolesents 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). 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 on the left side, held momentarily, and then rapidly released the child may experience a momentary increase in pain (rebound). This finding suggests inflammation has spread to the peritoneum.

If the appendix ruptures the pain may disappear for a short period and the child feels 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.