Transcript FUO 3
Definition
Fever higher than 38.3 Celsius on several occasions
Duration of fever for at least three weeks
Uncertain diagnosis after one week in the hospital
Definition
Unremarkable
History/physical
CBC w/ diff
Blood cultures
Chemistries with LFTs
Hepatitis serology if appropriate
UA/Urine culture
Chest film
Etiology
Connective tissue diseases
22 percent
Infections
16 percent
Malignancies
7 percent
Miscellaneous (drugs, clot, factitious)
4 percent
No diagnosis
51 percent
Infections
Tuberculosis
Especially in immunodeficiency
Normal CXR 15-30% of cases
Abscess
Usually in abdomen or pelvis
Predisposed by diabetes, recent surgery, steroid tx
Osteomyelitis
In cases with nonlocalized symptoms consider
vertebral or mandibular osteo
Infections
Bacterial Endocarditis/abscess
Culture negative cases
Coxilla burnetti (Q fever),
Tropheryma whipplei, Brucella,
Mycoplasma, chlamydia,
histoplasma, legionella, bartonella
HACEK organisms
Haemophilus, actinobacillus,
cardiobacterium, eikenella, and
kingella take 1 to 3 weeks to grow
Connective Tissue Diseases
Adult Still’s Disease
Daily fevers, arthritis, and evanescent rash
Giant Cell Arteritis
Headache, vision loss, arthritis
Jaw claudication
Polyarteritis nodosa
Takayasu’s arteritis
Wegner’s granulomatosis
Cryoglobulinemia
Malignancy
Leukemia/lymphomas
Typically determined by bone marrow biopsy or CT/MRI
imaging
Myelodysplastic syndrome
With dysplastic changes in blood line
Multiple myeloma
Malignancy
Renal cell carcinomas
Present with fever 20% of cases
Hepatitic metastases
Required for most other adenocarcinomas to cause fever
Atrial myxomas
Present with fever 1/3 of cases
Also with arthralgias, emboli, hypergammaglobulinemia
Drugs
“Drug fever”
Eosinophilia and rash in only 25% of cases
Antibiotics
Sulfa, PCN, Vancomycin, Antimalarials
Antihistamines
H1 and H2 blockers
Antiepileptics
Barbiturates and phenytoin
Drugs
NSAIDs
Antihypertensives
Hydralazine, methyldopa
Antiarrythmics
Quinidine, procainamide
Stop for 72 hours and monitor for
improvement/defervescene
Factitious Fever
Underlying psychiatric condition
Typically in women and healthcare professionals
Besides manipulation of thermometers fever can be
induced by
Taking meds which pt is allergic to
Injecting foreign matter parenterally
Milk, urine, culture media, feces
Other
Disordered heat homeostasis
Follows hypothalamic dysfunction typically after massive CVA
or anoxic brain injury
Hyperthyroidism
Dental abscess
Less common infections
Pulmonary
Q fever, leptospirosis, psittacosis, tularemia
Nonpulmonary
Syphillis, disseminated gonococcemia, Whipple’s disease, RMSF
Alcoholic hepatitis
Fever, hepatomegaly, jaundice
Other
Pulmonary embolism/DVT
Hematoma
Hip, pelvis, retroperitoneum
Pheochromocytoma
Adrenal insufficiency
Familial Mediterranean fever
Diagnosis
History and physical with focus on
Travel
Animal contacts
Immunosuppression
Drug history
Localizing symptoms
Laboratory Work-up
Chem-10
CBC w/ differential
ESR or CRP
TB skin test
HIV antibody
Rheumatoid factor
CK
ANA
SPEP
Blood cultures x 3 separated by space and time off
antibiotics
Imaging
Recommend if appropriate
CXR
CT Abdomen/Pelvis or Chest
Replaced exploratory laparotomy
Helpful in localized abscess, LAD
Not recommended unless otherwise indicated
Bone scan
Biopsy
Bone marrow biopsy
Malignancy, TB
Liver biopsy
Sarcoidosis, TB
Lymph node biopsy
Lymphoma, infection
Temporal artery biopsy
Giant cell arteritis
Therapy
Empiric antibiotics are not recommended given
Possible suppression without cure
Abdominal abscess
Unknown length of treatment
Endocarditis
Steroids also may be consider
However must be relatively certain no infection present
Must be certain not to interfere with inflammatory
workup
Steroids or antibiotics empirically rarely aid in
diagnosis and risk harm to patient
Outcome
Many FUOs end up with no definitive diagnosis
About 50% of people without diagnosis improve
within hospitalization or soon thereafter
15% have persistent fever that lasts at least 1 year
Rarely does death develop from FUOs
References
Bleeker-Rovers, CP, et al. A prospective multicenter study
on fever of unknown origin: the yield of a structured
diagnostic protocol. Medicine (Baltimore) 2007; 86:26.
Petersdorf, RG. Fever of unknown origin: An old friend
revisited. Arch Intern Med 1992; 152:21.
Hirshmann, JV. Fever of unknown origin in adults. Clin
Infect Dis 1997; 24: 291.
Vandershueren, S, et al. From prolonged febrile illness to
Fever of unknown origin: the challenge continues. Arch
Intern Med 2003; 163: 1033.
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