Fever Phobia

When our two-year-old ran a fever of 102, my aunt told me to put him in a bath of ice water. How long should we leave him in there?

What???

Our answer is—make sure your aunt reads this chapter. We’re going to provide you with a good understanding of “fever” and hopefully release you (and your aunt!) from a pervasive problem—“fever phobia.” Let’s start with the basics.

Our body temperatures are controlled by a specific location in our brains—the hypothalamus. Here resides the “thermoregulatory center,” which balances heat production and heat loss. This is important to keep in mind, since it’s the site of action for the drugs we use to lower our temperature. This “center” is able to maintain our body temperatures in a normal range, in spite of environmental factors, such as cold and heat. We have a “set point” for this, and we’re able to make adjustments, using increased metabolic activity (in a cold environment) and sweating (in a hot environment). When we have a fever, it’s this “set point” that gets messed up, usually due to some kind of infection. Our brains reset to what it thinks our new normal temperature should be.

When asked about a normal temperature, most of us would answer “98.6 degrees,” and we would be right. Probably. This number comes from several studies done in the 1800’s. More recent information indicates that normal body temperatures vary with age, level of activity, time of day, and even with the phase of a woman’s menstrual cycle. It seems that an upper limit of normal would be 98.9 degrees in the morning and 99.9 overall. We know that infants and young children have higher “normal” temperatures than older children and adults. For instance, in the newborn period (age 0 to 28 days), the average normal temperature is about 99.5 degrees, with an upper limit of 100.4. So technically in this age group, 100.0 is not a fever. This normal range increases a little as a child gets older, but only a little. As mentioned, normal temperature varies during the day, with our lowest occurring in the morning, and the peak in the late afternoon or evening. This variation can be as much as 1.8 degrees. Something else to keep in mind when you’re monitoring your child’s temperature.

Alright, but what’s the best way to check my child’s temperature? I see all kinds of stuff on the internet.

For those of us who have/had two-year-olds (or any child less than five), we know that taking their temperature can be a challenge. The easiest answer would be a tympanic membrane (TM) thermometer, or maybe one of the forehead devices placed on their skin. But that would be the wrong answer. Aside from those, we have the choice of a rectal, oral, or axillary (armpit) temperature. The “gold standard” is the rectal route, up until the age of 5 years. After that, an oral temperature would be the first choice (if our child will cooperate), followed by an axillary temperature. Let’s consider these methods.

A rectal temperature is the basis for most medical studies and is the most accurate measurement of our “core temperature.” If we’re going to base significant medical decisions on our temperature measurement, we want it to be as accurate as possible. Those decisions can lead to extensive workups, including x-rays, lab studies, and even spinal taps.

Oral thermometers are going to be preferred by a child who is old enough to cooperate, but can be affected by the recent ingestion of hot or cold liquids. Make sure you wait at least fifteen minutes after your child has had something to drink before taking their temperature. Also, they need to be able to keep the thermometer in a closed mouth during the entire process. Mouth breathing will give us an inaccurate reading. We were taught that an oral temperature is typically 1 degree cooler than a rectal measurement, and that still seems to be the rule.

An axillary measurement can be used (with your oral thermometer—not rectal) but will be consistently lower than a rectal reading. This difference varies too much to come up with an agreed upon number, but it may be as much as 2 degrees cooler. This temperature will give us some information, but it will be limited. If it’s critical to know the core temperature of a child, the rectal temp is still the best.

We’ve already mentioned the TM and the forehead thermometers. Easy, non-threatening, and too inaccurate to be of help. Save your money.

Now that we’ve measured our child’s temperature, what constitutes a “fever?” Most experts agree that a fever is an abnormal elevation of temperature that results from our brain (remember the hypothalamus) responding to several changes in our body, the most common of which would be a viral/bacterial infection. This “abnormal elevation” depends on the age of your child, how the temperature was measured, and what might be causing it. In most instances, the height of a temperature is less important than the appearance of your child and the presence of worrisome physical findings—irritability, a stiff neck, lethargy. It’s important to know what we would consider to be “fevers of concern.” Temperatures in this area will prompt a more extensive examination and search for a specific cause. These ranges assume that your child has been previously healthy.

• 0 to 3 months of age – a rectal temperature equal to or greater than 100.4 degrees
• 3 months to 6 months – a rectal temperature equal to or greater than 102.2 degrees
• Older children – an oral temperature equal to or greater than 103.1 degrees

What causes these elevations in temperature? What’s going on here? We mentioned our brain’s temperature “set point.” When “inflammatory” chemicals are released by the actions of viruses, bacteria, and even our own white blood cells, they travel to our brains and “reset” our set point to a higher level. Our body responds by doing what it’s supposed to do—raise our temperature to the new set point. Our brain sends signals to increase metabolism and increase muscle tone and activity (hence the shivering we experience with a fever). This goes on until we reach the new mark. The upper limit seems to be 107.6 degrees. Pretty scary. This can happen with a “heat stroke,” but is usually limited to 106.0 degrees without something external going on. Still pretty scary.

I’ve always been told that our brains fry at a temperature of 105! That’s why we need to treat every fever that our child has.

Nope, and not necessarily. Fever does not cause brain damage, even in the extreme. And we’re going to consider when and if a fever needs to be treated at all.

Some researchers think that fever can actually be our “friend.” There is some evidence that an elevated temperature can retard the growth and multiplication of certain bacteria and viruses. And since it is a normal response to those inflammatory chemicals we mentioned, it may have additional roles in fighting infection, such as improving our immune response. These possible benefits are minimal, and in some circumstances, fever does more harm than good. It makes us uncomfortable and irritable. And it increases our metabolic rate (shivering is an example), thus placing increased demands on our heart and lungs. For previously healthy children, this is not a significant factor. It becomes significant in the child with a heart condition or things like asthma.

Since fever is a sign of an underlying disease process, we need to try to determine its cause. Frequently, it’s going to be a simple viral infection. But it could be something more serious, such as a bacterial infection.

I’ve heard that if my child’s fever goes down with acetaminophen, it’s most likely a viral infection, since this won’t happen with a bacterial problem.

I’ve heard that too, and it’s dead wrong. A child’s response to acetaminophen or ibuprofen won’t help us distinguish between a viral or bacterial infection. Wish it did. That would make all of our lives simpler. That’s one important point we need to be aware of regarding our approach to fever. Here are some others:

• Fever is not a disease or illness, but a normal bodily response.
• There is no evidence that fever—no matter its height—makes an illness worse.
• Most fevers (in previously healthy children) are self-limited—they will resolve on their own.
• Fever does not cause brain damage.
• The first things to do to reduce a child’s elevated temperature are to provide extra fluids and reduce their physical activity (they will usually do this on their own).
• If a child is uncomfortable because of the fever, that’s an indication to treat it.
• If your child has a fever and you’re treating it, don’t wake them up to give them their fever medicine.
• Pay attention to other medications your child is taking, such as cough and cold preparations. Many of these contain acetaminophen or ibuprofen and can lead to an accidental overdose.
• Fever medications are given according to weight and not age. This is important, since dosing by age can lead to under or over-dosing. Ask your physician for a 5 or 10 cc syringe to help you with accurate dosing, since the ones provided with OTC medications are frequently inaccurate.

“Fever medications” act by restoring the thermoregulatory set-point we talked about at the beginning of this chapter. We have a couple of these medicines, with acetaminophen and ibuprofen being the most commonly used. Aspirin falls into this category but should not be used due to its association with Reye’s syndrome in children and teenagers (brain swelling, vomiting, confusion, seizures, liver failure—something none of us want). Make sure you check the contents of any of your children’s OTC medications that are in your medicine cabinet and throw out anything with aspirin in it.

Before we decide on starting one of these medicines, we need to keep in mind that routinely treating every fever in an otherwise healthy and normal child is not always indicated. This isn’t a disease. There’s no evidence that reducing fever will improve the time course or severity of the underlying cause. In addition, use of these medicines can lead to drug toxicity and may delay the identification of a serious infection. Yet, reducing your child’s fever can improve their discomfort and may reduce the risk of dehydration, through less water loss from sweating. It’s a case by case decision, but since most of these decisions are made by parents without the consultation of their family doctor, let’s be sure we know as much about these medications as we can.

Most pediatricians would recommend acetaminophen as their first choice for treating fever. It has a long track record for safety (when dosed correctly) and is effective in lowering an elevated temperature. Ibuprofen is effective as well—maybe slightly more so than acetaminophen—and it has a longer duration of action. Most preparations taste better than those with acetaminophen, but ibuprofen has more potential for toxicity, especially for the kidney.

Here’s what we need to know about acetaminophen. It’s not recommended for infants younger than three months of age (unless directed by your doctor), mainly since it may mask the presence of a potentially life-threatening infection. We have to be careful with the dosing of this medicine, since too much can cause life-threatening liver problems. Follow the directions on the bottle or box and you should be fine. If you’ve heard that a “loading dose” might be helpful (twice the regular dose), don’t do it. It only causes confusion and increases the risk of an overdose. Expect acetaminophen to begin working in 30 to 60 minutes and reach its peak effect in 3 to 4 hours. It’s duration of action is anywhere between 4 and 6 hours. More than 80% of children will have their temperatures reduced by as much as 3.6 degrees.

Now, about ibuprofen. It shouldn’t be given to an infant younger than six months of age, unless directed to do so by your physician. Pay attention to the dosing of this drug as well. It’s spaced out a little more, with at least 6 hours between doses. It begins working in less than an hour and has a peak effect in 3 to 4 hours—a little quicker than acetaminophen. The duration of action is 6 to 8 hours and it lowers an elevated temperature to the same degree (see what we did there?) as does acetaminophen.

What about combining or alternating these medicines? Is that safe?

It might be safe, but we don’t recommend it. Once again, fever is not a disease, and we don’t want anyone obsessing with getting their child’s temperature back to normal. Obsessing with that can lead to “fever phobia,” which might actually be a disease. Hmm. Anyway, the American Academy of Pediatrics advises against this practice, mainly because it can increase the possibility of inaccurate dosing. Pick your medicine and stick with it. If you start with acetaminophen and don’t get the desired response, that would be the appropriate time to switch to ibuprofen—but not add it or alternate the two medicines.

The “desired response” for your child is to make them more comfortable. We’re not recommending that you chase a fever until it’s back to normal, only that you see that the medicine is causing your child to feel better. That’s the goal with these drugs. As a caution, if the fever persists for more than four or five days, it’s time to have them examined. And if there are new findings of confusion, a stiff neck, widespread rash, or decreased fluid intake, that can be an emergency. Get help.

Regarding “external cooling” methods, we generally don’t recommend them. Sponging with alcohol should never be done, due to the risk of adverse effects. And sponging with tepid water might help a little, but the effect is short-lived and your child won’t like it.

So this is what we need to know—what causes a fever, when it should be treated, and how to treat it. Fever phobia? Forget it.

And about putting your child in an ice bath. This would be a timely application of Luke 6:31. “Do unto others…”

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This is an excerpt from the new book I’m writing with pediatrician Dr. Robert Alexander. The book will address 100 questions from parents regarding their children’s health. Feel free to email us with questions: askthedox@yahoo.com