Medical Illustrations

Appendicitis: Inflammation of the appendix, the small worm-like projection from the first part of the colon. Appendicitis usually involves infection of the appendix by bacteria that invade it and infect the wall of the appendix. Appendicitis can progress to produce an abscess (a pocket of pus) and even peritonitis (inflammation of the lining of the abdomen and pelvis).

The most common signs and symptoms of appendicitis are fever, and abdominal tenderness, and right lower quadrant abdominal pain most marked at what is called McBurney's point. Appendicitis is suspected on the basis of the patient's history and physical examination. A white blood cell count, urinalysis, abdominal x-ray, barium enema, ultrasonography, CT scan, and laparoscopy also may be helpful in diagnosis.

Because of the varying size and location of the appendix and the proximity of other organs to the appendix, it may be difficult to differentiate appendicitis from other abdominal and pelvic diseases. The treatment for appendicitis is antibiotics and appendectomy (surgery to remove the appendix). Complications of appendectomy may include wound infection and abscess.

The most exquisitely tender area of the abdomen in the early stage of appendicitis, this point is named after the New York surgeon Charles McBurney (1845-1913), the leading authority in his day on appendicitis. In 1889, McBurney showed that incipient appendicitis could be detected by applying pressure to a particular spot in the right lower abdomen, a point he called the "seat of greatest pain," which corresponds to the normal location of the base of the appendix.