From the Research
The Rochester criteria are not directly applicable to the provided evidence, as the studies focus on fever of unknown origin (FUO) in adults, rather than febrile infants. However, based on the most recent and highest quality study 1, the etiology of FUO can be categorized into infectious diseases, non-infectious inflammatory diseases, neoplastic diseases, and miscellaneous diseases. The clinical characteristics and common inflammatory parameters, such as C-reactive protein (CRP) level, erythrocyte sedimentation rate (ESR), and serum ferritin (SF) level, can be used to determine the etiology of FUO. Some key points to consider in the diagnosis of FUO include:
- Infectious diseases are the most frequent cause of FUO, followed by non-infectious inflammatory diseases 1
- The tuberculosis T lymphocyte spot test (T-SPOT.TB) and CRP level may be used as indicators to diagnose infections in patients with FUO 1
- Female gender, young age, high white blood cell (WBC) count and percentage of neutrophil percent (NP), high ESR, and elevated SF level may contribute to the diagnosis of non-infectious inflammatory diseases 1
- Male gender, old age, low hemoglobin (HB) concentration and platelet (PLT) count, and high lactate dehydrogenase (LDH) and SF levels may contribute to the diagnosis of neoplastic diseases 1 It is essential to note that the diagnosis of FUO requires a comprehensive history, physical examination, and laboratory tests, and a focused diagnostic approach based on clinical clues from the history, physical examination, and laboratory tests may be useful in reaching a diagnosis 2. In clinical practice, a thorough evaluation of the patient's history, physical examination, and laboratory tests is crucial in determining the etiology of FUO and guiding treatment decisions.