Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2024 Jun 10;11(7):ofae298.
doi: 10.1093/ofid/ofae298. eCollection 2024 Jul.

Recommendations for Updating Fever and Inflammation of Unknown Origin From a Modified Delphi Consensus Panel

William F Wright  1 , Lauren Stelmash  2 , Albrecht Betrains  3 , Catharina M Mulders-Manders  4 , Chantal P Rovers  4 , Steven Vanderschueren  5 , Paul G Auwaerter  6 ; International Fever and Inflammation of Unknown Origin Research Working Group
Collaborators, Affiliations

Recommendations for Updating Fever and Inflammation of Unknown Origin From a Modified Delphi Consensus Panel

William F Wright et al. Open Forum Infect Dis. .

Abstract

Background: Fever of unknown origin (FUO) and inflammation of unknown origin (IUO) are syndromes commonly used as medical diagnoses. Since the existing literature has a mixture of diagnostic approaches, developing consensus-based recommendations would be helpful for clinicians, researchers, and patients.

Methods: A modified Delphi process was performed from October 2022 to July 2023, involving 4 rounds of online surveys and 2 live video conferences. The panel comprised international experts recruited based on peer-reviewed published publications and studies.

Results: Among 50 invited experts, 26 (52.0%) agreed to participate. Twenty-three panelists completed round 1 of the survey, 21 completed rounds 2 and 3, 20 completed round 4, and 7 participated in round 5 live video discussions. Of the participants, 18 (78.3%) were academic-based clinicians and researchers, 5 (21.7%) practiced in a community-based hospital, and 6 (26.1%) were female. Consensus was reached on 5 themes: (1) incorporating epidemiologic factors, such as geographic location and travel history; (2) updated criteria for classifying FUO or IUO; (3) initial evaluation approaches; (4) a classification system for diagnoses; and (5) recommendations for judicious limitation of empiric therapies. Experts strongly disagreed with using 2-deoxy-2-[18F] fluoro-D-glucose positron emission tomography/computed tomography as part of the diagnostic criteria for FUO. There were mixed opinions about the importance of the temperature measurement site, the 3-week minimum illness criterion, the need for a standard definition of relapsing fevers, and the use of similar evaluation strategies for FUO and IUO.

Conclusions: These Delphi-generated consensus-based recommendations offer potential improvements compared with earlier definitions and a guide for clinical practice and future research.

Keywords: fever; fever of unknown origin; inflammation of unknown origin; pyrexia; pyrexia of unknown origin.

PubMed Disclaimer

Conflict of interest statement

Potential conflicts of interest. P. G. A. reports stockholdings in Johnson & Johnson. All other authors report no potential conflicts.

References

    1. Wright WF, Mulders-Manders CM, Auwaerter PG, Bleeker-Rovers CP. Fever of unknown origin (FUO)—a call for new research standards and updated clinical management. Am J Med 2022; 135:173–8. - PubMed
    1. Wright WF, Betz JF, Auwaerter PG. Prospective studies comparing structured vs nonstructured diagnostic protocol evaluations among patients with fever of unknown origin: a systematic review and meta-analysis. JAMA Netw Open 2022; 5:e2215000. - PMC - PubMed
    1. Vanderschueren S, Del Biondo E, Ruttens D, Van Boxelaer I, Wauters E, Knockaert DD. Inflammation of unknown origin versus fever of unknown origin: two of a kind. Eur J Intern Med 2009; 20:415–8. - PubMed
    1. Betrains A, Wright WF, Moreel L, Staels F, Blockmans D, Vanderschueren S. Etiological spectrum and outcome of fever and inflammation of unknown origin. Does symptom duration matter? Eur J Intern Med 2022; 106:103–10. - PubMed
    1. Petersdorf RG, Beeson PB. Fever of unexplained origin: report on 100 cases. Medicine (Baltimore) 1961; 40:1–30. - PubMed