Boas' sign

Boas' sign, also written Boas's sign, is hyperaesthesia, meaning increased or altered sensitivity, below the right hypochondrium or in the region of the twelfth rib. It can be a sign of acute cholecystitis, inflammation of the gallbladder, and is one of many signs a medical provider may look for during an abdominal examination. Originally the sign referred to point tenderness to the right of the tenth to twelfth thoracic vertebrae, and the source reports it is less than 7 percent sensitive. It is named for Ismar Isidor Boas (1858 to 1938), a German physician and the first licensed gastrointestinal specialist in his country. Pressure over the transverse processes of the tenth to twelfth thoracic vertebrae has also been used to point to stomach or duodenal disease, on the left of the spinous processes for a lesser curvature ulcer and on the right for a pyloric or duodenal ulcer. This is a historical clinical description, not medical advice.