With more than 200 causative diseases, fever of unknown origin (FUO) is one of the most difficult diagnostic challenges for doctors. As there is no standard diagnostic approach for FUO, non-clue-based testing can often lead to inefficient and misleading diagnosis. Thus, timely accurate diagnosis is essential for appropriate treatment of the underlying cause of FUO. Therefore, this article discusses the diagnostic algorithm for accurate diagnosis of FUO.
Fever of unknown origin (FUO) in adults is a temperature higher than 38.3 °C (100.9 °F) lasting for more than three weeks; and a failure to reach a diagnosis despite one week of inpatient investigation. For FUO, a characteristic history and physical examination together with specific test results are the basis for a successful clue-directed diagnosis. Following section describes a detailed diagnostic algorithm for FUO. Differential…
