Fever of Unknown Origin (FUO) Questions & Answers

Updated: Mar 01, 2018
  • Author: Sandra G Gompf, MD, FACP, FIDSA; Chief Editor: Michael Stuart Bronze, MD  more...
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Questions & Answers

Overview

What are key features of fever of unknown origin (FUO)?

How is the syndrome of fever of unknown origin (FUO) defined?

How is fever defined in fever of unknown origin (FUO)?

How are the conditions of the differential diagnosis of fever of unknown origin (FUO) categorized?

How common is the etiology of fever of unknown origin (FUO) identified as a noninfectious inflammatory disease?

What are noninfectious inflammatory causes of fever of unknown origin (FUO)?

What are common infectious inflammatory causes of fever of unknown origin (FUO)?

What are less common infectious causes of fever of unknown origin (FUO)?

What are malignant and neoplastic causes of fever of unknown origin (FUO)?

What are miscellaneous causes of fever of unknown origin (FUO)?

What are patient education resources for fever of unknown origin (FUO)?

What is the prognosis of fever of unknown origin (FUO)?

Presentation

Which symptoms suggest a malignant cause of fever of unknown origin (FUO)?

What should be the focus of history for fever of unknown origin (FUO)?

What should be evaluated in the history for fever of unknown origin (FUO)?

How do fever patterns help in the identification of the etiology of fever of unknown origin (FUO)?

Which symptoms suggest a noninfectious inflammatory cause of fever of unknown origin (FUO)?

Which symptoms suggest an infectious inflammatory cause of fever of unknown origin (FUO)?

Which etiologies of fever of unknown origin (FUO) are suggested by a history of specific animal exposures?

Which etiologies of fever of unknown origin (FUO) are suggested by travel-related or environmental exposures?

When should HIV or gonorrhea be considered as the etiology of fever of unknown origin (FUO)?

Which history may suggest a viral etiology for fever of unknown origin (FUO)?

Which symptoms suggest a miscellaneous cause of fever of unknown origin (FUO)?

What are the initial steps in the physical exam of fever of unknown origin (FUO)?

Which physical findings suggest specific causes of fever of unknown origin (FUO)?

DDX

What are diagnostic considerations for tuberculosis in fever of unknown origin (FUO)?

How often does fever of unknown origin (FUO) remain undiagnosed?

What are diagnostic considerations for hepatobiliary infections in fever of unknown origin (FUO)?

What are diagnostic considerations for osteomyelitis in fever of unknown origin (FUO)?

What are diagnostic considerations for parasitic infections in fever of unknown origin (FUO)?

What are diagnostic considerations for a drug-related fever of unknown origin (FUO)?

What are diagnostic considerations for collagen-vascular and autoimmune diseases in fever of unknown origin (FUO)?

Which conditions may cause fever of unknown origin (FUO)?

What are the differential diagnoses for Fever of Unknown Origin (FUO)?

Workup

What is the basis for selection of diagnostic tests in fever of unknown origin (FUO)?

What is the role of lab studies in the workup of fever of unknown origin (FUO)?

What is the indication for an HIV serology test in the workup of fever of unknown origin (FUO)?

What is the role of erythrocyte sedimentation rate (ESR) in the workup of fever of unknown origin (FUO)?

What is the role of a complete blood cell (CBC) count in the workup of fever of unknown origin (FUO)?

What is the role of a complete metabolic profile in the workup of fever of unknown origin (FUO)?

What is the role of urinalysis in the workup of fever of unknown origin (FUO)?

What is the role of blood cultures in the workup of fever of unknown origin (FUO)?

What is the role of tuberculosis screening in the workup of fever of unknown origin (FUO)?

Which lab findings suggest a specific cause for fever of unknown origin (FUO)?

How should assays, serology, and cultures be selected for the workup for fever of unknown origin (FUO)?

What is the role of chest radiography in the workup of fever of unknown origin (FUO)?

What is the role of CT angiography in the workup of fever of unknown origin (FUO)?

What is the role of echocardiography in the workup of fever of unknown origin (FUO)?

What is the role of CT scanning in the workup of fever of unknown origin (FUO)?

What is the role of positron emission tomography (PET) scanning in the workup of fever of unknown origin (FUO)?

What is the role of radionucleotide studies in the workup of fever of unknown origin (FUO)?

What is the role of bone scanning in the workup of fever of unknown origin (FUO)?

What is the role of a naproxen test in the workup of fever of unknown origin (FUO)?

What is the role of endoscopy in the workup of fever of unknown origin (FUO)?

What is the role of biopsies and tissue sampling in the workup of fever of unknown origin (FUO)?

Treatment

What are the treatment options for fever of unknown origin (FUO)?

What are the specific examples of treatment for fever of unknown origin (FUO)?

When is inpatient treatment indicated for fever of unknown origin (FUO)?

How is fever of unknown origin (FUO) managed?

What is the indication for transfer in patients with fever of unknown origin (FUO)?

Which specialist consultations are needed for the treatment of fever of unknown origin (FUO)?

What long-term monitoring is needed for fever of unknown origin (FUO) that remains undiagnosed?

Medications

How are medications for fever of unknown origin (FUO) selected?