Pyrexia

I shall deviate from Neurology to talk about something that many of my friends are suffering from now.

Pyrexia (common name: Fever)

Fever is a common term to describe a medical symptom in which a human's internal body temperature rises to temperatures above normal. Fever is not a neurological disease, but can be brought about by one. Fever is brought about by pathogens (biological agent which can cause disease to its host). It is a postive feedback mechanism which opposes the homeostatic negative feedback thermal regulatory mechanism. As with any positive feedback mechanism, fever aims to achieve a normal body condition by raising the internal body temperature to denature enzymes which enable the pathogen to work, indirectly killing the pathogen itself. Thus fever cannot be labelled as a disease, but rather as a symptom and as the body's defense mechanism towards pathogens.

As mentioned above, Fever is caused by infections and thus is not termed a disease. However, there are drugs to stop the development of fever. These drugs are called antipyretics. Acetaminophen or Paracetamol (Panadol) are examples of it. These drugs inhibit the production of the cyclooxygenase enzyme responsible for inducing the increase in body temperature.

However, antipyretics only suppress the fever and stops the positive feedback mechanism. They do not inhibit the source of it. Thus, a patient who is immunodeficient may be on antipyretics alone for months without antibiotics and die. Antibiotics must be prescribed together with the antipyretics so as to minimize the fever and to eliminate the source of infection which results in the fever. Thus it is absolutely necessary to see a doctor to obtain antibiotics when fever arises. However, a patient may recover totally without the use of antibiotics as the body's immune system will produce its own antibodies to combat the infection, but the time for recovery would be significantly longer.