Fever – Unknown Origin

Fever – Unknown Origin: Excerpt from In A Page: Pediatric Signs and Symptoms

Fever of unknown origin (FUO) is a term that is often misused to describe febrile illness without an obvious etiology or without other symptoms. The definition in different studies is arbitrary, but basically refers to at least 2 weeks of daily documented fever that is unexplained despite repeated physical examinations and initial laboratory investigation, in an immunocompetent host. In approximately 12% of cases an etiology cannot be found.

Differential Diagnosis

• Infections (40%)
  –Infectious mononucleosis (EBV, CMV)
  –Other systemic viral syndromes (e.g., HIV)
  –UTI (e.g., E. coli)
  –Osteomyelitis (e.g., staphylococcus)
  –Upper and lower respiratory infections (sinusitis, mastoiditis, pneumonia)
  –Cat-scratch disease (Bartonella henselae)
  –Tuberculosis, nontuberculous mycobacterial infections
  –Abscess (abdominal or retroperitoneal)
  –CNS infections
  –Endocarditis (subacute)
  –Salmonellosis
  –Lyme disease (Borrelia burgdorferi)
  –Leptospirosis
  –Congenital syphilis
  –Others: Brucellosis, histoplasmosis, leishmaniasis, yersiniosis, Q fever (Coxiella burnetii), Rocky Mountain spotted fever (Rickettsia rickettsii)

• Autoimmune diseases (15%)
  –Rheumatoid arthritis accounts for 3/4 of FUO due to autoimmune diseases
  –Systemic lupus erythematosus
  –Rheumatic fever
  –Vasculitis (e.g., HSP)
  –Sarcoidosis
• Neoplastic diseases (7%)
  –Leukemia/lymphoma accounts for 80% of
  FUO due to malignancies
  –Neuroblastoma
  –Hepatoma
  –Soft tissue sarcoma
• Inflammatory bowel disease (3%)
• Drugs and nutritional supplements (drug fever)
• Factitious fever
• Munchausen by proxy
• Neurologic disorders
  –Familial dysautonomia
  –Central thermoregulatory disorder
  –Head injury
• Hyperthyroidism
• Anhidrotic ectodermal dysplasia
• Diabetes insipidus
• Kikuchi disease

Workup and Diagnosis

• History
  –Differentiate between FUO and multiple febrile
• illnesses that occur in short period of time
  –Daily documentation of fever, onset, duration
  –Weight loss, diet history, medications, sick contacts
  –Animal or tick exposure, travel, foreign contacts
  –Immune status, history of transfusion, surgery
  –FH of autoimmune or neoplastic diseases
• Physical exam
  –Vital signs, growth parameters
  –Skin (rash, desquamation, jaundice)
  –Ophthalmologic exam (conjunctivitis, uveitis)
  –Oral lesions
  –Cardiologic exam (new onset murmur)
  –Abdominal exam (masses, hepatosplenomegaly)
  –Testicular exam
  –Muscle tenderness, bone tenderness, arthritis
  –Lymphadenopathy
  –Neurologic exam
• Labs
  –CBC, ESR, C-reactive protein
  –Renal and hepatic function tests, albumin and globulin
  –Urinalysis, blood and urine culture
  –Viral titers, PPD, cultures for specific organisms, ASO, ANA, bone marrow
• Radiographic imaging with plain films, ultrasound, bone scan, CT scan or MRI of specific organ systems as warranted by the history and physical exam

Treatment

• Specific treatment once diagnosis is made
• Empiric treatment with antibiotics is to be considered only for critically ill patients
• Empiric steroids may be justified only if Still disease is suspected
• Anti-inflammatory agents are sometimes used for a limited period of time and subsequently the patient is observed for recurrence of the fever
• Cessation of offending drugs

Book Source Details

• Book Title: In A Page: Pediatric Signs and Symptoms
• Author(s): Jonathan E. Teitelbaum, Kathleen O. Deantonis, Scott Kahan
• Year of Publication: 2007
• Copyright Details: In A Page: Pediatric Signs and Symptoms, Copyright © 2007 Lippincott Williams & Wilkins.

More About Acute rheumatic fever

• Back to disease: Acute rheumatic fever: Introduction
• Next Book Extract About Acute rheumatic fever: Fever – Acute (In A Page: Pediatric Signs and Symptoms)
• More Book Extracts: All Online Books for Acute rheumatic fever

More Medical Textbooks Online about Acute rheumatic fever

Review other book chapters online related to Acute rheumatic fever:

Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.

More About This Book: Title: In A Page: Pediatric Signs and Symptoms Authors: Jonathan E. Teitelbaum, Kathleen O. Deantonis, Scott Kahan Publisher: Lippincott Williams & Wilkins Copyright: 2007 ISBN: 1-4051-0427-9

 » Next page: Fever – Acute (In A Page: Pediatric Signs and Symptoms)

Rate This Website

What do you think about the features of this website? Take our user survey and have your say:

Website User Survey

Medical Tools & Articles:

Next articles:

• Fever – Acute (In A Page: Pediatric Signs and Symptoms)
• FEVER (Differential Diagnosis in Primary Care)
• Fever (Handbook of Signs & Symptoms (Third Edition))
• Fever of Unknown Origin in the United States* (A Pocket Manual of Differential Diagnosis)
• Infection and Fever (Complications of HIV) (A Pocket Manual of Differential Diagnosis)

Tools & Services:

• Bookmark this page
• Symptom Search
• Symptom Checker
• Medical Dictionary
• Give your feedback

Medical Articles:

• Disease & Treatments Search
• Misdiagnosis Center
• Full list of interesting articles

Forums & Message Boards

• Ask or answer a question at the Boards:
• I cannot get a diagnosis. Please help.
• Tell us your medical story.
• Share your misdiagnosis story.
• What is the best treatment for my condition?
• See all the Boards.

Enter your search terms Submit search form
Search The Web Search wrongdiagnosis.com

Common Health Mistakes

Symptom
Checker

Search Specialists by State and City