In Hannah Johnson's case, what notable sign suggested potential diabetic ketoacidosis?

The presence of a fruity odor to the breath is a notable sign suggestive of diabetic ketoacidosis (DKA). This characteristic scent is primarily due to the presence of acetone, a type of ketone that accumulates in the bloodstream when the body is unable to utilize glucose effectively, typically in cases of uncontrolled diabetes mellitus. In those experiencing DKA, the metabolism shifts toward fat breakdown, leading to increased levels of ketone bodies, including acetone, which can be exhaled and result in the distinct fruity smell.

While the other symptoms listed, such as dry skin, high temperature, significant weight loss, and an increased heart rate, can be associated with various medical conditions, including dehydration or other complications arising from diabetes, they are not as specific to DKA as the fruity breath odor. This specific sign can serve as an important diagnostic clue, prompting further investigation and management of a potential diabetic crisis.