Amongst various current criteria for FUO (Fever of Unknown origin), one relates to body temperature =
**Core Concept**
The Centers for Disease Control and Prevention (CDC) criteria for Fever of Unknown Origin (FUO) is a set of guidelines used to diagnose and manage patients with prolonged fever of unknown origin. The criteria include various parameters such as duration of fever, temperature, and other clinical findings.
**Why the Correct Answer is Right**
The CDC criteria for FUO include a temperature of at least 38.3°C (100.9°F) for a sustained period, typically more than three weeks. This temperature threshold is used to differentiate FUO from other febrile illnesses. The prolonged elevation of body temperature is a significant indicator of an underlying inflammatory or infectious process.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not specify a temperature threshold. A temperature of 38°C (100.4°F) is not sufficient to diagnose FUO.
**Option B:** This option is incorrect as it does not specify the duration of fever. A single episode of fever is not indicative of FUO.
**Option C:** This option is incorrect as it specifies a temperature threshold that is too low. A temperature of 37.8°C (100°F) is not sufficient to diagnose FUO.
**Clinical Pearl / High-Yield Fact**
It is essential to note that FUO is a diagnosis of exclusion, and a thorough evaluation of the patient's medical history, physical examination, and laboratory findings is necessary to determine the underlying cause of the fever.
**Correct Answer:** C. 38.3°C (100.9°F)