Question 63

Fever occurring several times over at least 3 weeks is used to diagnose Fever of Unknown Origin (FUO) in adults.

Fever of Unknown Origin (FUO) is characterized by fever that occurs repeatedly over a sustained period, specifically for at least 3 weeks, which aligns with the criteria for diagnosis.

A) Fever occurring several × over at least 3 weeks

This option accurately describes one of the key criteria for diagnosing FUO. A fever that persists and occurs several times over a duration of at least 3 weeks is essential for categorizing a fever as unexplained, guiding further investigation into potential underlying causes.

B) Fever occurring at least once per day for 8 days

While this option suggests a pattern of fever, it does not meet the established criteria for FUO, which requires the fever to persist for a minimum of 3 weeks. Thus, although it indicates a prolonged fever, it is insufficient for diagnosis.

C) Body temperature of 100.4 degrees Fahrenheit or greater

This option provides a threshold for fever but does not address the duration necessary for FUO diagnosis. A temperature of 100.4 degrees Fahrenheit is a common definition for fever, yet it does not encompass the criteria of persistence and duration that define FUO.

D) Elevated white blood cell count

An elevated white blood cell count may indicate an underlying infection or other conditions but is not a definitive criterion for diagnosing FUO. The diagnosis relies more on the temporal aspect of fever rather than laboratory findings alone.

Conclusion

In summary, the correct answer is option A, as it specifically addresses the duration and frequency required for diagnosing Fever of Unknown Origin. Options B, C, and D fail to meet the necessary criteria of time and pattern that are central to the definition of FUO, making them incorrect in this context.