Jul 22, 2019 · Fever of Unknown Origin (FUO) - Etiology, pathophysiology, symptoms, signs, diagnosis & prognosis from the Merck Manuals - Medical Professional Version.

Immune reconstitution inflammatory syndrome is a common cause of FUO when a previously suppressed immune system is reactivated. The newly active immune system often has an …

Infection, neoplasia, and non-infectious inflammatory disease are the most common causes of classic FUO. No guidelines exist, but minimum obligatory investigations should include …

Feb 2, 2022 · FUO is not a biologically uniform phenomenon but rather a common manifestation of multiple, disparate disease processes. There are different classifications for FUO that are …

Nov 6, 2025 · Clinicians commonly refer to a febrile illness without an initially obvious etiology as fever of unknown origin (FUO). However, most febrile illnesses either resolve before a …

Apr 9, 2024 · Fever of unknown origin (FUO) was defined in 1961 by Petersdorf and Beeson as the following: (1) a temperature greater than 38.3°C (101°F) on several occasions, (2) more …

Aug 14, 2023 · Fever of unknown origin (FUO) was first described by Dr. Petersdorf and Dr. Beesom in 1961. FUO was defined as a temperature of 101 degrees Fahrenheit (38.3 degrees …

Feb 21, 2025 · Fever of unknown origin (FUO) is defined as a temperature of > 38.3°C (100.9°F) lasting for > 3 weeks with no clear etiology despite appropriate diagnostics. Infections, …

The approach to a patient presenting with fever of unknown origin (FUO) should include a comprehensive history, physical examination, and appropriate diagnostic testing

Although not usually considered separately, FUO in solid organ transplant recipients and FUO in the returning traveler are common scenarios, each with a unique differential diagnosis, and are …