Which sign is indicative of appendicitis when rebound tenderness is present in the right lower quadrant?

The presence of rebound tenderness in the right lower quadrant is a classic indicator of peritoneal irritation, which is often seen in appendicitis. McBurney's sign specifically refers to tenderness localized to a point about one-third of the distance from the anterior superior iliac spine to the umbilicus. When this sign is positive, it indicates that the inflamed appendix is causing irritation to the peritoneum in that area, making it a key sign in diagnosing appendicitis.

In contrast, other signs related to appendicitis may not provide the same focused indication of appendicular inflammation. Rovsing's sign involves palpation of the left lower quadrant leading to pain in the right lower quadrant, indicating peritoneal irritation rather than directly depicting appendicitis. The obturator sign and Blumberg's sign (which is synonymous with rebound tenderness) also signify peritoneal irritation but do not specifically localize to the right lower quadrant in a manner exclusively indicative of appendicitis.

Thus, McBurney's sign is the most relevant and specific sign associated with appendicitis in the context of rebound tenderness in the right lower quadrant.