What is a classic sign of acute appendicitis?

A classic sign of acute appendicitis is rebound tenderness at McBurney's point. This tenderness is assessed during a physical examination when pressure is applied to the abdomen and then quickly released. If there is pain upon release, it indicates irritation of the peritoneum, which occurs in conditions like appendicitis. McBurney's point is located in the right lower quadrant of the abdomen, approximately one-third of the distance from the anterior superior iliac spine to the navel. The presence of rebound tenderness specifically at this location supports the diagnosis of appendicitis.

Other signs and tests do exist in the evaluation of abdominal pain, but they reflect different conditions or aspects of diagnosis. Positive Murphy's sign is associated with cholecystitis, as it indicates pain upon palpation of the gallbladder. A negative Rovsing's sign, which tests for referred pain felt in the right lower quadrant when the left side of the abdomen is palpated, is less indicative than its positive counterpart, which would be relevant in diagnosing appendicitis. Positive Prehn's sign is utilized in testing for epididymitis and refers to the relief of pain when the scrotum is lifted, making it unrelated to appendicitis.