Should fever due to infections be treated?

Question

Recently I read in an article

The mechanism of fever appears to be a defensive reaction by the body against infectious disease. When bacteria or viruses invade the body and cause tissue injury, one of the immune system’s responses is to produce pyrogens. These chemicals are carried by the blood to the brain, where they disturb the functioning of the hypothalamus, the part of the brain that regulates body temperature. The pyrogens inhibit heat-sensing neurons and excite cold-sensing ones, and the altering of these temperature sensors deceives the hypothalamus into thinking the body is cooler than it actually is. In response, the hypothalamus raises the body’s temperature above the normal range, thereby causing a fever. The above-normal temperatures are thought to help defend against microbial invasion because they stimulate the motion, activity, and multiplication of white blood cells and increase the production of antibodies. At the same time, elevated heat levels may directly kill or inhibit the growth of some bacteria and viruses that can tolerate only a narrow temperature range

Now usually as soon as we realise that we have fever, we immediately take antipyretics, eg. Paracetamol. Now it will cool the body temperature. Isn't this dangerous and wrong?

My question is regarding fever due to infections only.

Answer 1

In normal patients fever can reduce our efficiency or comfort for doing work. For mild infections one may wait for the fever to get over and let our immune response do their job.

For early and effective treatment we prefer antibiotics with antipyretics as antibiotics can do their job alone and fever might not be necessary here. It will give early response than giving antipyretic alone or letting fever be alone.
The other point is that, we prefer antibiotics with antipyretics because the organism inflicting it may cause more damage to our body before getting killed by immune system and thus increasing morbidity and mortality.

Fever is not the only mechanism to fight infection, some people take antipyretics alone which reduces fever and provides comfort but our immune system alone is effective enough to curb some mild infections, so people who take antipyretics alone are not in too much danger but it may prolong the illness in some cases. It is not the general prescribed method and antipyretics should be used with indications like other drugs and not for fever per se (though this reference is for the pediatric population but in general practice, antipyretics are generally not given alone for infections and the same argument can be applied)

For some common viral fevers only conservative treatment is required. Antipyretics are given if temperature is too high because in that case its benifit can outweigh the effects of having fever, otherwise we must let fever to happen recognising the fact that fever is beneficial or not is still controversial (considering the fact that fever in this case can be benificial.)

Finally, there can be many other indications for the use of antipyretic to reduce fever, not just considering a simple argument that it can enhance the immune response eg. paracetamol is given in dengue fever or antipyretics are given to prevent febrile seizures. So I recommend taking antipyretics under the prescription of the concerned medical professional only.

Answer 2

As you have already described, the hypothalamus regulate the set point at which the body temperature is maintained. This set point is elevated in fever, reflecting an infection, or resulting from tissue damage, inflammation, etc. These conditions all enhance formation of cytokines such as IL-1beta, IL-6, TNF-alfa, and interferons, which act as endogenous pyrogens; this first phase is mediated by ceramide release in neurons of the preoptic area in the anterior hypothalamus. The second phase is mediated by coordinate induction of COX-2 and formation of PGE2 which (by a cascade of reactions) will trigger the hypothalamus to elevate body temperature by promoting an increase in heat generation and decrease in heat loss.

NSAID's (Nonsteroidal Anti-Inflammatory Drug) supress this response by inhibiting COX-2 and thus as well as the synthesis of PGE2. This is the fundamental therapeutic effect of this class of drugs - inhibit prostaglandin (PG).

Now regarding your question specifically, NSAID's reduce fever in most situations, but not the circadian variation in temperature or the rise in response to exercise or increased ambient temperature. Normal body temperature in healthy humans is not affected by NSAID's because there are no PG's triggering the hypothalamus in normal conditions.

There is a danger however... and that is due to toxicological effects specially with paracetamol (acetaminophen) which may cause liver injury with unintentional overdose; and if the drug has too much affinity for COX-2 enzymes (some companies were very well sued for that)

References

Rang & Dale's Pharmacology

Sorry, I misread your whole question.. the question was if it is good or not to have fever, you can remove the upvote if you like.

I've found this article which concludes that

Early administration of acetaminophen to treat fever due to probable infection did not affect the number of ICU-free days

That is a true dilemma, in one hand it is relatively safe to not take any antipyretic medication for minor illnesses, and let the system defend itself, on the other as some studies reveal it does not affect or worsen the outcomes.