Fever in children

What can cause fever in children?

There are 3 conditions that can cause the body temperature to rise:
– Production of, or presence of pyrogens (substances that raise temperature).
– Production of more heat than one can get rid of
– Problems with the ability to get rid of heat

We will be focusing on the first of the three conditions detailed above.

Pyrogens are endogenous (produced inside the body) and exogenous (produced outside the body) substances that increase the body’s temperature threshold in the central nervous system (hypothalamus).
Sensitized cells in our body produce additional pyrogens. One of the more significant pyrogens produced by these cells is named prostaglandin E2 and it can also affect the hypothalamus.
Exogenous pyrogens, such as molecules released by different pathogens (illness producers, mostly viruses or bacteria), are the ones that start the series of events leading to fever, for the most part.

What kind of conditions can raise a child’s temperature through the first mechanism described above?

Infectious conditions of course, but also other medical conditions such as cancer, inflammation, and different medications. Nonetheless, in children, most fevers are caused by infections.

How do the well-known antipyretic and analgesic drugs work?

Antipyretic drugs are also analgesics and they do so by interfering with the different physiologic paths that cause fever to rise.
Acetaminophen – most probably inhibits the COX family enzymes which produce prostaglandins. It does not inhibit inflammation. It is absorbed in the intestines and broken down by the liver.
Ibuprofen – belongs to the family of drugs that is non-steroidal (non-steroidal anti-inflammatory drugs) or in short, NSAIDS. It inhibits the production of prostaglandins.

What is considered fever for a child? What is hyperpyrexia? Read more in the next chapter.