We describe the definition, diagnostic workup, causes and treatment of FUO.įDG-PET Fever of unknown origin connective tissue disease diagnosis infection malignancy systemic autoinflammatory diseases treatment. Fever of unknown origin (FUO) vasculitis, 183185 malignancies, 2733 malignant causes, 188 neoplastic, 2728 noninfectious inflammatory causes. The majority of patients with unexplained FUO will eventually show spontaneous remission of fever. The prognosis of FUO is determined by the underlying cause. Corticosteroids should be avoided in the absence of a diagnosis, especially at an early stage.

This article discusses the causes, diagnosis, and treatment of FUOs. The treatment of FUO is guided by the final diagnosis, but when no cause is found, antipyretic drugs can be prescribed. Fever of unknown origin (FUO) is defined as a temperature elevation of 101 degrees F (38.3 degrees C) or higher for 3 weeks or longer, the cause of which is not diagnosed after 1 week of intensive in-hospital investigation. Even with a standardised protocol, in a large proportion of patients from western countries the cause for FUO cannot be identified. In the absence of PDCs a standardised diagnostic protocol should be followed with PET-CT as the imaging technique of first choice. PMID: 34437835 DOI: 10.1016/j.amjmed.2021.07. Evaluation starts with the identification of potential diagnostic clues (PDCs), which should guide further investigations. While there is no accepted definition in veterinary patients, FUO is considered to be present when an obvious cause for a persistent fever has not been found.

More than 50 years after the first definition of fever of unknown origin (FUO), it still remains a diagnostic challenge.