Fever Flashcards
What is a normal temperature?
Normal temperature varies throughout the day and typically 36.8 ±0.8 ℃
Definition of a fever
An elevation in core body temperature above the daily range for an individual”
Body temperature fluctuates throughout the day
Mackowiak et al. JAMA 1992:
Normal temperature = 36.8 ±0.8 ℃
Abnormal → Temperature ≥37.3℃ in the early morning
Abnormal → Temperature ≥37.8℃ overall
Definition of fever
Regulated by the hypothalamus in response to pyrogens, resulting in a rise in core temperature ≥37.8℃
Definition of hyperthermia
Not regulated by the hypothalamus and is an uncontrolled body temperature rise
Causes of hyperthermia
Heat stroke syndromes
Metabolic diseases
Pharmacological agents
Neurological injury
Causes of hyperthermia resulting from serotonin syndrome reactions?
Cocaine NMDA (ecstasy) Amphetamines Tricyclic antidepressants (TCAs) Selective serotonin reuptake inhibitors (SSRIs) Monoamine oxidase inhibitors (MAOI) Lithium
What are exogenous pyrogens?
EXOGENOUS PYROGENS are derived from outside of the host and mainly microbes and their products
What are endogenous pyrogens?
ENODENOUS PYROGENS are host-derived biologically active proteins (pyrogenic cytokines)
What is the definition of Pyrexia of Unknown Origin (PUO)?
The PUO definition has 3 criteria:
- Fever ≥37.8℃ on several occasions
- Duration of fever ≥21 days
- Uncertain diagnosis after one week of investigation in hospital