Posted tagged ‘infection’

“How high was the fever?” isn’t a very useful question

December 3, 2015

The Pediatric Insider

© 2015 Roy Benaroch, MD

A September, 2015 study published in the Pediatric Infectious Disease Journal looked at whether fever itself – the height of a fever – is a good predictor of whether a child is likely to have a serious illness. And, once again, a common fever myth is shattered.

Researchers reviewed data from visits from children, aged 0-5 years, who presented to a pediatric hospital for fever in 2004-2006. (Yes, that was an oddly long time ago. I guess they write slowly in Australia. But in terms of the science, there haven’t been any big changes in vaccines or childhood illness since then, so I think the results are still valid.) Of the almost 16,000 fever episodes reviewed, about 1,000 children had what the authors considered a “serious infection”. That includes bacteremia (bacteria in the blood) in 64 children, pneumonia in 533, and urinary tract infection in 543. In total, only about 7% of the children had a potentially serious bacterial infection that needed to be treated. That percentage should be no surprise—we know that in the modern world, among vaccinated and healthy children, the vast majority of fevers are caused by viral infections that will get better on their own.

The authors then looked at whether the height of the children’s fever correlated well with whether or not they ended up having a serious diagnosis. They examined both the measured highest fever in the emergency department, and the parents’ self-reported “highest fever” in the last 24 hours, prior to their visit. Whichever way it was recorded, the height of the fever itself did a very poor job at discriminating between children who had and did not have a serious infection.

The statistics are complicated, and involve receiver operating curves that you may not be  familiar with—but, in the author’s words, “Measured temperature at presentation to hospital is not an accurate marker of serious bacterial infection in febrile children.”

Relying on the height of a fever resulted in both false positive and negative results. For instance, evaluating only those with a temperature of 100.4 or higher would still miss 1 in three serious infections. You can’t rely on high fevers as a positive predictor, either—only 1 in 6 children with a temperature of 104 actually had a serious infection.

The authors found that a few other observations could be at least somewhat predictive. Younger babies, overall, were a little more likely to have serious infections; and children who had had fevers for more than 4 days were also somewhat more likely to be diagnosed with something more serious (though I imagine those children also had more tests done, like chest x-rays. Perhaps they just found more illness when they looked for more illness.) But even when adding in considerations of age and length of illness, the height of the fever remained a poor predictor of the seriousness of the illness.


So what’s a parent to do?

First: prevent serious illness by making sure your children are up to date on their vaccines. We can prevent most causes of meningitis, pneumonia, blood poisoning, and other serious bacterial and viral infections with vaccines. Prevention is always better than having to evaluate and treat children in an emergency department or office visit.

Then: offer comfort care to children with fever. Extra fluids are a good idea, and if fever is causing a child to be uncomfortable, treat it. If Junior perks up and acts well after fever-reducing medication, and isn’t especially at-risk for serious infection**, treat fevers at home for a few days. If the child is getting worse, acting persistently sick, or isn’t getting better, go see your doctor. Remember: the number itself is less important than how your child feels and acts.

** This advice does not include any child less than 2-3 months old, or with an immune deficiency, or who isn’t up to date on vaccines for any reason. These kids are at much higher risk of serious or deadly infections, and shouldn’t rely on advice from the internet. Call your doctor for specific fever instructions.


More about fever:

What is a fever?

Why do kids get fevers?

Dispelling fever phobia

The fever action plan


fever rita moreno

The best thermometer for measuring fever in a child is….

May 9, 2013

The Pediatric Insider

© 2013 Roy Benaroch, MD

There are lots of choices, so which one is best? Which kind of thermometer should parents buy and use?

Keep in mind that body temperature is one measurement—but it’s certainly not the only measurement, and it’s far from the most important way of knowing if your child is ill. Kids can be seriously sick without a fever; and almost all ordinary children with fever do not have a serious illness. There’s far too much “fever phobia” out there, and there’s already far too much preoccupation with whether Junior has a fever and how high the temperature is. Fever itself doesn’t hurt anyone. It doesn’t cause any damage, and won’t hurt your child. But fever can make your child feel sick, so it’s worthwhile to treat it. Safe medicines for fever can help your child feel more comfortable.

Also, any discussion of fever needs a caveat: all of this information is only for healthy, otherwise-well children with no immune-compromising condition. That means children who have NOT gotten all of their vaccines are NOT healthy and otherwise-well, and have a much greater risk of serious, even overwhelming infection. If your child isn’t up to date on vaccines, I offer no advice on how to measure or handle temperatures. Call your doctor. Better yet, unless there is a medical contraindication, get your child caught up on vaccines, pronto. You wouldn’t drive without your child in a safety seat, would you?

Another fun fever fact, before we get to the meaty stuff: if anyone has told you that 98.6 F is the “normal” temperature, they’re wrong. It’s not normal, it’s average. 98.6 is no more the normal than saying 5’10” is the normal male height. As with every other measurement in nature, temperatures vary among individuals, and temperatures vary throughout the day. 98.6 is the average, meaning that normal ranges from below this to above this. In most circumstances, most pediatricians consider anything measured at 100.4 or above to be a fever. Values measured below that threshold are not “low grade fevers”—they’re normal temperatures. And don’t start adding degrees, depending on how you measured the temp. That just confuses everyone.

So what are the choices for thermometers, and which should you choose? I’m going to include links here to Amazon products, just so you know what I’m talking about. (I have no financial relationship, and I don’t care if you buy through these links, etc.)

Mom or dad’s hands: These actually make a reasonably good thermometer, at least for “ruling out” fever. If you touch your children, and they do NOT feel warm, they almost certainly do not have a fever. The inverse of this, by the way, is not true: often your child will feel warm, and won’t actually have a fever—so touch can rule out fever, but cannot confirm or measure a fever. But it’s a start, and for busy people with older, healthy kids, using your hands alone is not an unreasonable way to check.

Rectal thermometer: These work, though they’re slow. They’re also the only method used in most studies of small babies less than 2-3 months of age, so typically that’s what pediatricians want you to use at that age. But please, no rectal temps in older kids, OK? It’s just creepy and unnecessary.

Axillary thermometer, AKA “The Chicken Wing”: These work, though they’re also kind of slow. Not bad for an estimate. Kids feel silly sitting there holding their arms still, but that’s the price they have to pay.

Oral thermometer: Those old, mercury-filled ones you have to shake back down have gone the way of the dinosaurs. They’re all digital now, and they read faster. And if you shake one down after reading it people will edge away from you and give you odd looks. These work about as well as the others in this list.

So far, rectal/axillary/oral, it’s all good, at least when they’re appropriate for the age. But they’re all old school. Isn’t there something newer that’s better?

Binky-temps (AKA: a digital thermometer built into a pacifier): Please. This measures, maybe, the temperature of the top of the tongue, wherever that’s been lately. Don’t waste your money.

Forehead tape thermometers: These have vague glowing numbers that indicate, well, where the vague glowing numbers are. Might as well make up a temperature rather than rely on these things.

Infrared thermometers: The ones marketed to parents are sometimes called “non-contact” thermometers, because these don’t actually touch your child. They’re also sold at hardware stores to measure the surface temps of things from quite a long way away, like industrial transformers or crème brulee. They are not suitable for people-use, because they only measure surface temperature. We want core temperature, or the temperature of the blood as it exits the chest. The temperature of the skin is NOT an acceptable or accurate way to measure core temps.

Forehead thermometers:  One company sells a digital version of what’s essentially your hand, touching your child’s forehead. Use your own appendages instead, they’ll be just as accurate, and they’re much more handy! (Get it? Handy?! Hahahahaha. Hem. Sorry.)

Ear thermometers: Supposedly these measure the temperature in the middle ear, where the monkeys live (or so I’ve been told.) Several years ago, a company that will remain nameless (hint: the name rhymes with mermo-flan) gave my practice a dozen or so of these, so we could try them out. I guess they figured we’d love them, and patients would see us using them, and they’d rush out and buy them too. Trouble is, the darn things were terrible—they missed high temps, they inflated no-temps, they gave children random fevers. So we threw them all away. If you’ve already bought one, maybe you can repurpose it as a chicken cutlet pounder or decorative paperweight.

Temporal artery thermometer: I’ve save the best for last! It’s quick, it’s easy, and a recent study showed that it’s pretty much as good as a rectal temp.

So: if your child feels warm, and you’d like to measure the temp, a temporal artery thermometer may be the best way to go. They’re more expensive than an ordinary digital thermometer for oral or axillary use, but they’re faster and I think they’re easier to use.

We have a winner!

More about fevers:

The fever action plan

Why do people get fevers?

Medicines for treating fever

Don’t touch those toys

January 27, 2009

When you visit the pediatrician, keep your children away from the toys in the waiting room. It’s better to bring your own toys than to expose your kids to things that might make them sicker.

A study presented in October, 2008 confirmed that toys and other surfaces in the common areas of pediatrician’s offices often harbor disease-causing viruses. Furthermore, the use of disinfecting wipes really doesn’t make much of a difference.

Almost all common cold germs are picked up from contaminated surfaces by hands. You can bet that the surfaces, chairs, and toys in a doctor’s waiting room are probably coated with an infectious sheen of microorganisms. Children innocently rubbing their eyes or noses are probably inoculating themselves with a stew of whatever germs were left by the last sick child in the waiting room. This study confirms that these germs can survive for up to 24 hours, and are difficult to eradicate from surfaces even with good thorough wiping.

Colds may seem like an unavoidable nuisance, but there are some effective ways that can help your family stay healthy. Avoid sick people, get a good night’s sleep, keep your hands clean, and bring your own toys to the pediatrician’s office.