Pyrexia, the fever faces many stages and types depending on the virulence of a stimulus. The pathophysiological changes to adopt, to protect our body the entire systems intergrate together to eliminate forcibly by enforcing immunity
Stages of Fever
Chill Stage :
When Hypothalamus set point is increased by Pyrogens , body temperature doesn’t reach the increased set point level immediately.
To increase the body temperature body will produce chill, shivering etc., this continue up to the body temperature reach the set point.
Chill and shivering g Produces vasoconstriction at periphery and this leads the external surface of skin to become cold.
The Crisis (or) Flush ie. Heat & Sweat Stage:
If pyrogens are removed - Hypothalamus set point suddenly reach the normal level, but body temperature still remains in higher level.
To reduce the body temperature (ie. To reach hypothalamus set point / normal level) body will produce heat flushes with hot skin due to vasodilatation and sweating, by which body temperature cool down to normal level.
TYPES OF FEVER:
1. Continuous Fever : The temperature remains above normal throughout the day and does not fluctuate more than 10 C in 24 hrs Eg. Lobar Pneumonia , Typhoid, Urinary tract infection, Infective endocarditis, Brucellosis, Typhus etc.,
2. Remittent Fever : The temperature remains above normal throughout the day and fluctuates more than 10 C in 24 hrs. Eg. Typhoid, Infective endocarditis etc., This type of fever is most
common in practice.
3. Intermittent Fever : The temperature is present only for some hours in a day and remits to normal for the remaining hours. When the spike occurs daily it is Quotidian, when every alternate day it is tertion and when every third day it is quartan. Intermittent fever is seen in malaria, Kala – azar , Pyemia, Septicemia etc.,
4. Hectic (or) Septic : The temperature variation between peak nadir is very large and exceeds 50 C eg. Septicemia.
5. Pel Ebstin Type : There is a regular alternation of recurrent bouts of fever and afebrile periods. The temperature may take 3 days followed by apyrexia for 9 days seen in Hodgkin’s lymphoma.
Low grade Fever : Temperature is present daily especially in the evening for several days but does not exceed 37.80 C at any time.
Usually it does not indicate disease, but it is commonly present with Tuberculosis.