Perhaps the most common surgically correctable cause of abdominal pain, the diagnosis of acute appendicitis remains difficult in many instances. Some of the signs and symptoms can be subtle to both the clinician and the patient and may not be present in all instances. Arriving at the correct diagnosis is essential, however, as a delay in diagnosis may allow progression to perforation and significantly increased morbidity and mortality. Incorrectly diagnosing a patient with appendicitis, although not catastrophic, often subjects the patient to an unnecessary operation.
Typically, the appendicitis illness begins with vague midabdominal discomfort followed by nausea, anorexia, and indigestion. The pain is persistent and continuous but not severe, with occasional mild cramps. There may be an episode of vomiting, and within several hours the pain shifts to the right lower quadrant, becoming localized and causing discomfort on moving, walking, or coughing. The patient may feel constipated.
Examination at this point shows localized tenderness to one-finger palpation and perhaps slight muscular guarding. Rebound or percussion tenderness (the latter provides the same information more humanely) may be elicited in the same area. Peristalsis is normal or slightly reduced. Rectal and pelvic examinations are likely to be negative. The temperature is only slightly elevated (eg, 37.8 °C) in the absence of perforation.