Lec 11 Fever of Unknown Origin Flashcards
Fever that goes down but not to normal
Remittent
Most accurate means of obtaining routine estimates of core temperatures
Rectal thermometry
Induce fever, hypoglycemia, shock and death that are seen after administration of LPS (lipopolysaccharides)
a. IFN-gamma
b. TNF-a
c. IL-1
d. AOTA
e. NOTA
d. AOTA
Antipyretic medications block conversion of arachidonic acid to prostaglandin by inhibiting:
cyclooxygenase
T/F: Fever is harder on adults than children
True
Definition of Classic FUO by Durack and Street:
- Temperature of >38.3 (>101 F) on several occasions
- Fever of duration > 3 weeks
• 3 outpatient visits or 3 days in the hospital without elucidation of cause or 1 week of “intelligent and invasive” ambulatory investigation (instead of the outpatient component, the duration for investigation
was lessened because of available technology for diagnosis)
Leading cause of FUO
Infections
T/F: As the duration of fever increases, the likelihood of an infectious cause of FUO decreases.
True!
Infections predominate early in FUO diagnoses, and the longer FUO remains undiagnosed, the less likely it is caused by an infection. After infections, the etiology of FUO transitions to noninfectious inflammatory diseases and malignancies, which can guide subsequent testing.
The emphasis in the approach to FUI is on a, observation b. examination c. empiric therapy d. AOTA e. A and B only
e. A and B only
Test involving giving of NSAIDs for 3-5 days; if fever disappears, fever is most likely from a noninfectious origin.
Naproxen Test
T/F: When no underlying source of FUO is identified after prolonged observation (6 months), prognosis is generally good.
TRUE
Risks of antipyresis
- Vasospasm of diseased coronary arteries due to cold pressor response (leading to tissue infarction)
- Vasoconstriction in patients with CAD (again leading
to tissue infarction) - Drug toxicity and adverse events (ex. NSAID allergy, gastric bleeding)
T/F: Fevers are always caused by infections
F
T/F: Viral infections cause the acute phase response much less than bacterial infections
T
Which of the following is NOT an effect of fever on host defense?
Enhanced neutrophil migration
a. Increased production of antibacterial substances by
neutrophils
b. Increased production of interferons
c. Increased antibacterial/antiviral activity of interferons
d. Increased T cell proliferation
e. AOTA
f. NOTA
f. NOTA
Effects of fever on host defense:
• Enhanced neutrophil migration
• Increased production of antibacterial substances by
neutrophils
• Increased production of interferons
• Increased antibacterial/antiviral activity of interferons
• Increased T cell proliferation
• Decreased growth of microorganisms
• IL-1, TNF- α, IFN induce fever, hypoglycemia, shock and death that are seen after administration of LPS
(lipopolysaccharides)
• Potentially deleterious effects of febrile response and
chemical mediators
