The Carnett sign describes an examination finding used to distinguish pain arising from the abdominal wall from pain arising from within the abdomen itself.
Eliciting the sign was described as a two-stage procedure. First the examiner locates the point of maximal tenderness through palpation of the abdomen in the usual manner with the patient's abdominal muscles relaxed, then asks the patient to tense their abdominal muscles (for example, by lifting their head from the pillow) and applies pressure to the same point. If the tenderness is still present with the rectus muscles tensed, the pain is likely to originate in the abdominal wall, for example due to a rectus sheath hematoma 1.
History and etymology
The sign was described by John Berton Carnett (1890–1988), an American surgeon in May 1926 2.