The correct answer is:

temperature of 40°C

Educational Objective:

Discuss signs that provide an early focus within the very broad work-up of a patient with confusion.

Key Point:

Any physician knows that looking at the vital signs is an important first step in ANY patient; however, it is surprisingly often forgotten in the confused patient.

Explanation:

A complete set of vital signs, including temperature, is a critical component of evaluating confusion and may yield important clues that initiate a more specific search – in this case a physical search for physical cues of infection (cellulitis, abscess, etc), and also urine and cerebrospinal fluid analysis, a chest x-ray, various lab tests (WBC, etc) and blood cultures.

Other etiologies must of course also be kept in mind; however, an infectious work-up will be a higher priority in a patient with a significant fever than a patient with completely normal vital signs.

Well-healed scars yield information about past events, but do not focus the differential work-up in this patient.