The Doctor is In: Fever in Kids

So, I’m giving in and giving my husband a space to talk about what he knows best: pediatric medicine.

Everyone?  This is Marshall.  Say hi(and ignore his visually maddening Twitter background). Today he’ll be talking about fever in kids.  But if there’s something else you’d like to see him write about, email me at queenofhaddock(at)gmail(dot)com and we’ll see what we can do.

***Disclaimer – this is my personal statement regarding fever and includes things that I tell my own patients/parents in visits to my office.  This is not meant to be a substitute for a visit to or discussion with your pediatrician.  For any questions regarding your child’s health you should of course discuss them with your pediatrician.  This is meant only to provide information, which I hope you find helpful.***

So as far as fever goes, it certainly carries a lot of parental anxiety with it, and often a lot of caregiver anxiety as well.  Fever has been recognized for centuries as part of the body’s mechanism for fighting infection.  Many species of animal have been able to survive because of their ability to mount a febrile response to invading pathogens, be they virus, bacteria, or other.  Certainly fever should be considered in the context of the individual patient’s presenting signs and symptoms (i.e. a child with a fever of 104 who is bouncing all over the exam room warrants a different response than a child with a temperature of 104 who is lethargic and unresponsive).  There are always exceptions to every rule or statement, so for the purposes of this discussion we’re talking about “normal” kids – those with normal immune systems, no complex medical history, etc.

To talk about fever we should also consider what’s normal.  Most people consider a temperature of 98.6 a normal temp, and start worrying as soon as you hit 99.  The 98.6 is often not where someone’s temperature is found to be even when well, just as most women don’t actually deliver on their “due date.”  The number considered by many to be “normal”  came about when a physician by the name of Carl Wunderlich conducted one million measurements of temperature on 25,000 adults using a 12 inch thermometer and obtaining readings from under the arm.  He then obtained the average of those readings to be 98.6, with ranges from 97.2 to 99.5.  An individual’s body temperature varies throughout the day and can change by more than a degree, with the normal low for the day being in the early morning and the normal high occurring in the early evening.  The definition of a true fever begins at 100.5 – so when the daycare calls you and says “your child has a temp of 99.5, come get them,” you can educate them on what defines fever.

The first thing I tell all my patients/parents is that fever is not harmful in and of itself. It certainly makes a child uncomfortable, and brings with it an increase in heart rate and breathing rate.  Most healthy children can handle these things well (again, those with chronic illness, heart or lung disease, immune system problems, or other abnormalities may not be as straightforward).  I’m often asked how high a fever can go before a parent should worry, and my answer is that there is no magic number at which I hit the panic button.  Certainly, if a patient has a 106, I’m going to want to examine them to see what’s going on, but the height of the fever is not nearly as reliable a predictor of serious illness – rather, the child’s clinical appearance is a much more reliable tool for assessing them.  One common concern is brain damage with high fevers.  Brain damage has never been shown to be caused by high fever, even in children with temperatures as high as 107.6 (although if my patient has a 107.6, I’m sure going to figure out why!).  In other words, a 104 is not “worse” than a 101, per se, just makes you feel really crummy.  Fever can easily be 104, 105 with common viruses as with bacterial infection.

Another common concern is seizures due to fever.  Certainly they can occur, and although scary for all involved, a single simple febrile seizure won’t cause any long-term ill effects (certainly still talk to your pediatrician, and if a child has more than one they may warrant further evaluation).  For info from the AAP(American Academy of Pediatrics) website regarding febrile seizures, go here.   Simple febrile seizures often occur with the initial temperature elevation at the beginning of the illness.  Often the seizure occurs first and fever is only discovered later.  As far as febrile seizures go, even though higher temperature has been shown in some studies to be an independent risk factor, the most aggressive fever treatment with Tylenol/Motrin won’t reduce the risk of a febrile seizure – so basically if a young child is going to have one, it’s going to happen.  When they do, they don’t cause any long term ill effects (although they’re quite scary at the time).  Any seizure activity, associated with fever or not, should of course be discussed with/evaluated by your child’s pediatrician.

As far as the fever response in the body, it has several potential benefits.  First, it elicits several inflammatory mediators which activate/enhance certain components of the immune system so the body can more efficiently fight off whatever bug (virus, bacteria, etc.) that’s causing infection.  It also makes it harder for the invading bug to do its thing (I like to compare it to yard work – it’s a lot easier to pull weeds when it’s 75 degrees outside than when 95 degrees. Likewise, it’s harder for invading bugs to work efficiently when body temp is higher).  So fever does provide some measure of protection.

Fever management is also a common point of inquiry.  Fever does bring with it an increased metabolism, so replacing the nutrients and water lost as a result will be crucial to good fever management.  Pushing fluids (Pedialyte is best) and making the child comfortable will help a great deal in accomplishing this.  Lukewarm bathing/sponging provides only a marginal improvement in temperature, and can make a child uncomfortable, so should largely be avoided.  Cold water or rubbing alcohol can constrict the surface blood vessels that help the child to dissipate heat, and therefore should absolutely be avoided.  A common misconception is that it’s more successfully managed with alternating Tylenol and Motrin every 3 hours or so.  (Interesting side note, AAP did a survey of pediatricians regarding that, and about 1/3 of those surveyed thought that AAP recommended alternating.  There is in fact no AAP stance/statement stating that one should alternate the two).  Alternating Tylenol and Motrin carries several risks. First, dose confusion is common, especially when it’s 2:00 in the morning and you can’t remember what you last gave your child.  Motrin and Tylenol are both metabolized in the liver, and Motrin can inhibit production of a protein (glutathione) that assists in the metabolism of Tylenol.  So, alternating the two over time can lead to increased Tylenol levels in the blood.  (**Any child with liver disease should not be dosed prior to discussion with a physician!!).  Dosing of either Tylenol or Motrin is based on weight, so especially for young children talk to your pediatrician about the best dose for your child’s weight (all 8 month olds are not created equal – my 8 month old weighs as much as some kids twice his age!).

Several studies have shown that Tylenol and Motrin are about equally effective in temperature reduction.  One thing to realize with treatment is that at proper weight-based dosing, the average response to treatment is a drop in 2 degrees that lasts for 2 hours.  So if you were to treat a 103.8 and it only went down to 101.8 that would not be a failure of treatment; rather, that would be a reasonable response.  The only reason to treat fever is for comfort – other than discomfort there are no generalized ill effects from fever.  Certainly I’m happy if a 103 goes to 98 with treatment, as that makes the child feel better, but we don’t always get that.  As far as which one to use, my office recommends Tylenol rather than Motrin for several reasons: First, Motrin can be irritating to the stomach, especially in a child who isn’t eating/drinking well and has a largely empty stomach.  Second, Motrin can inhibit some of the types of white blood cells that fight infection – there are some white blood cells whose job is to find the invading bug and eat it.  Motrin inhibits them in their activity (can provide you a link to the study from 1997 if interested), and therefore can slow the body’s ability to eliminate infection, especially if bacterial.  Third, Motrin has a slightly increased risk of decreasing blood flow to the kidneys if a child is already a little bit dehydrated.  (In fact every pediatric nephrologist I’ve spoken to is adamant that if a child has fever along with vomiting/diarrhea that they absolutely should not get Motrin).  Some may disagree with me on that last point, but if Tylenol and Motrin are fairly similar in effectiveness, and Motrin has potential for a short-term hit to the kidneys if the kiddo has a decreased circulating blood volume, (which is possible with fever) I say why chance it (could write several paragraphs on that, but I’ll spare you that one…).  Tylenol is effective, and carries none of those risks.

Those are the main points I usually cover.  Take home message is that fever does tell us there’s something going on (virus, bacteria, etc.), but is not harmful in and of itself, and can help the body do its job.  Keep in mind that if a cause for the fever is found (i.e. ear infection) and treatment is initiated, fever can persist for 24-48 hours after starting treatment, and even with good old fashioned cold viruses we expect fever to last 3-5 days.  Persistence of fever beyond that would warrant another look by your pediatrician to make sure nothing else is going on.  Certainly any concerns regarding fever and associated symptoms should be directed to your pediatrician.

Sources cited in this article:

  2. Avner, Jeffrey R. “Acute Fever.” Pediatrics in Review 30 (2009): 5-13.
  3. Hirtz, Deborah G. Pediatrics in Review 18 (1997): 5-9.
  4. Zielinska, Malgorzata, and Wladyslaw Fenrych. “The application of a flow cytometric assay for evaluation of phagocytosis of Neutrophils.” Acta Biochimica Polonica 44.1 (1997): 121-26.

DL05 Dr. Marshall Ivey, M.D.  joined Milledgeville Pediatrics in July of 2008.  He is  originally from Athens, Georgia.  He obtained an undergraduate degree in Microbiology from the University of Georgia.  He then attended medical school at the Medical College of Georgia in Augusta, Georgia.  He remained in Augusta after graduation from medical school to complete his training in Pediatrics at the Children’s Medical Center, completing both an internship and residency in Pediatrics.  Upon completion of residency he sat for the American Board of Pediatrics certifying examination and is currently board certified in Pediatrics.  He is married with three children, ages 4, 3, and 8 months.

8 Responses to The Doctor is In: Fever in Kids
  1. Brandi Strickland
    August 28, 2009 | 6:32 pm

    Thanks Marshall! I know so many people who need to read this. I am so thankful for you and Dr. Samper…we totally trust you with Gracy!!! God has blessed us with GREAT doctors for her!

  2. Becky
    August 28, 2009 | 8:46 pm

    I NEEDED THAT! I am “that Mom” who has 6 of the 7 digits dialed to the pediatrician’s ofc if we’ve got a 100.1 at our house. (surprise! I’m a worrier!) Seriously – great information!! Do you mind if I copy, paste & forward to all of my mommy girlfriends?

    More importantly (to me anyway!) could the good doctor PURDY PLEASE share a little bit of knowledge on the stomach bug? Not that I am one of those moms who is overly paranoid about getting it or anything. I let Drew out of his bubble at least once a day for 5 minutes you know!

  3. Becky
    August 28, 2009 | 8:47 pm

    One more thing…don’t you need to amend “Cinnawella” since the R’s are being pronounced now? GO EMMIE!!!

  4. Leigh Lumpkin
    August 29, 2009 | 9:15 pm

    Thanks Marshall for calming Becky down ;o) I am by no means a worry wart and have been blessed with 2 kids with great immune systems and the ability to show no signs of slowing down even with high temps, but I was told about the switching up of the Tylenol and Motrin when they were small, so that was an interesting tidbit that I learned. Thanks Bridget for letting Marshall have the floor. Please do it again soon!

  5. jeffra
    August 31, 2009 | 12:35 pm

    awesome, this really answered some questions for me…can you touch on fevers with teething too, sometime? Everything I have read says that a “low grade” fever may accompany teething, however my daughter, without fail, gets 103-104 fevers for about 3-4 days about a week before a tooth, or in her case teeth, emerge. Is this common and why is it said that higher fevers don’t coincide with teething? Thanks so much!