118 Fever Flashcards
Feature of an Intermittent Fever
Temperature returns to normal at least once every 24 hours.
Feature of Remittent Fever
Temperature does not return to normal but does vary a few degrees in either direction
Feature of Sustained Fever
Temperature remains above normal with only minimal variation
Feature of Relapsing Fever
A fever where there is one or more episodes of fever lasting as long as several days with one or more days of normal temperature between episodes
What is the relation between HR and Temperature?
1 Degree raise in temperature = 15bpm increase in HR
What is fever?
Fever is an elevation of body temperature above the normal range of 36.5 to 37.5 due to an increase in set point
What region of the brain regulates core body temperature?
The Hypothalamus
What are the 4 stages of a fever?
First/Prodromal
Second/Chill Phase
Third/Flush
Fourth/Defervescence
Characteristics of the First/Prodromal Phase?
Non-specific complaints such as headache, fatigue, malaise and aching
Characteristics of the Second/Chill Phase?
Sensation of being chilled
Onset of Shaking
Vasoconstriction and piloerection
When body temp reaches new set point, feeling of warmth develops
Characteristics of Third/Flush Phase?
Cutaneous vasodilation occurs and the skin becomes warm and flushed leading to the last phase
Characteristics of the Fourth/Defervescent Phase?
Initiation of sweating
Symptoms of Fever?
Feeling hot
Rigors - Shivering due to muscle activity (UTI)
Excessive sweating (Night sweats typical of TB and Lymphomas)
Delirium - Mental confusion especially in elderly and young children
Muscle pain - Myalgia and Arthralgia characteristic of viral infections and septicaemia illnesses
What is the average normal core temperature?
37.1 degrees
What is a Pyrogen?
A Pyrogen is a substance that causes fever.
They can be either Endogenous (Internal) or Exogenous (External)
What is the main Endogenous Pyrogen?
IL-6
Give some examples of Endogenous Pyrogens?
IL-1, IL-6, TNF-a, Interferon (INF)
What is IL-10
An antipyretic factor that limit febrile respond by competing with IL-6
What is the main Exogenous Pyrogen?
Lipopolysaccharide (LPS)
What are Acute Phase Proteins
Factors produced by the Liver to provide functions for the immune system
Give an example of a positive Acute Phase Protein?
C-Reactive Protein (CRP)
Stimulates Opsonin which activated the complement system
What is the difference between Fever and Hyperthermia?
Hyperthermia is the pathological increase in body temperature WITHOUT a change in set point within the Hypothalamus
What is Pyrexia of Unknown Origin
Consistently elevated body temperature of more than 38.3 persisting for 3 weeks with no diagnosis after initial investigations either after 3 days as an impatient or 3 outpatient consultations.
Give examples of common causes of Pyrexia?
Infection - Sepsis, Endocarditis, TB, HIV
Malignancy - Lymphoma, Melanoma, Leukaemia
Connective Tissue Disorders - RA, Lupus Erythromatosis, Rheumatic Fever
Miscellaneous - IBD, Drug Reaction, Sarcoidosis, DVT/PE
