Is your child’s head too big? Or just right?

Posted April 6, 2015 by Dr. Roy
Categories: Medical problems

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The Pediatric Insider

© 2015 Roy Benaroch, MD

“This chair is too big!” exclaimed Goldilocks. “And this chair is too small!”

“Just sit your rear down, missy!” said her mom, who had it up to here with her picky daughter. I mean, seriously?

Doctors and nurses and moms and dads, we all seem to like numbers. Unlike vague, untrustworthy adjectives (big? small?), they’re pointy and specific (23.5 centimeters!) I’ve even been known to crunch a number now and then. But when it comes to percentiles and measurements of growth, those pesky numbers sometimes cause more harm than good.

Tish wrote in, “I’m curious about head size, and when a parent should be concerned.  If a child is measuring well above the 97% line, but has no neurological symptoms and his growth curve mostly mimics that of other kids, is it likely just down to genetics?”

Too-short answer: Yes.

Too-long answer: Mostly, yes. But a head size that is too large—larger than expected for age and parents’ head size, or growing too quickly and shooting up off the chart—can actually be a serious and important thing, and can be an early sign of trouble.

Genetics plays a role, sure. The most common cause, by far, for a child to have a big head is “benign familial macrocephaly”. Mom and/or dad has a big noggin’, so Junior has a big noggin. As Tish says, as long as Junior is growing and thriving and otherwise well, a big headed kid with big headed parents needs to plan on buying big hats. But otherwise, there’s usually nothing to worry about.

How big should adult heads be? The data is pretty sparse. Seriously, if one of you wants to launch a survey site measuring normal adult heads to develop some good tables of normal values by gender/size/ethnicity, that would be really helpful. Maybe make it a Facebook page, “Measure your head!” or something like that. Until that’s done, we’re stuck with just a handful of published studies. The classic one is from 1992, and, yes, it’s still quoted in my pediatric textbook right here. All of the data comes from 354 white adults in Great Britain. We learn here that head circumference varies by height and sex. The 97%ile—a good “upper limit of normal” for an adult male of average height is 23 ½”; for a woman, the 97%ile is about 23”. Go check out your own size—see how it compares!—by wrapping a tape measure around your head.

The problem with that 1992 data is: I don’t actually believe it. I measure adult heads pretty frequently, and they’re often over 23-24 inches. There is some newer data out there—a Canadian study from 2012 recruited 280 all-male volunteers—that seems to show adult head circumferences are larger than they were in the 1992, but no one has done a very good, broad survey. So: even though we know big headed parents have big-headed kids, we don’t actually know how to define a big-headed parent. Maybe we should just ask about hat sizes, or ask Goldilocks what her opinion is (that head is too big!)

I did say this answer was the too-long version, didn’t I?

Big heads that we need to worry about fall into one of a few categories. Any head that’s quickly crossing percentiles upwards—going from, say, average, to Large, to HUGE over just a few months—is of Big Concern. A big head in a child who’s not meeting developmental milestones, or is losing milestones, is also a Big Red Flag. And big heads accompanied by obvious physical exam findings, like a bulging fontanelle, or a baby that’s hard to wake, or a baby that’s often fussy or irritable or vomiting—those need a Big Workup, pronto.

But for most kids with a big head, watchful waiting and a tape measure for mom and dad are all that’s needed.

Just-right answer: Frankly, I’m surprised you made it this far. I don’t really have anything else to say about big heads. Perhaps I didn’t think this Goldilocks motif through. Instead of another big head answer, I’ll send you to this short story I wrote. It has princesses and dragons and only a little bit of gore. Enjoy!

 

edit: The original title of this post was “Head too big? Too Small? Or just right?”– which was fine, until someone pointed out that I never actually got around to discussing small heads. So I changed the title. I can do that. 

Have no fear- your vegetables are loaded with toxins

Posted March 30, 2015 by Dr. Roy
Categories: In the news, Pediatric Insider information

Tags: , ,

The Pediatric Insider

© 2015 Roy Benaroch, MD

There’s so much fear and uncertainty out there. If you pay any attention to Facebook and Teh Interwebs, the air is killing is, the water is killing us, and, worst of all, our food is killing us. Chemicals!

Let’s straighten out some simple misperceptions. I promise, this won’t hurt.

Truth 1: Your food is loaded with chemicals.

It’s true. A chemical is just a compound or a substance that can be isolated or identified. Water is a chemical, salt is a chemical. Ethyl butanoate, phenylalanine, and aspartic acid are all chemicals, too, and they’re all a natural part of what makes a banana. Some chemical names look scary – like 3-methylbut-1-YL-ethanoate, another banana constituent. Others look friendly, like “ricin.” But ricin isn’t a natural part of rice (it actually comes from the castor bean.) It’s a deadly poison, and just one milligram of it can kill you.

 

So: all food is all chemicals, and whether or not the name of the chemical is scary has nothing to do with how much or how little it might harm you.

 

 Truth 2: Your food is loaded with pesticides, too.

OK, I get it—“chemical” is just shorthand for “bad chemical”. And by “bad chemicals”, we mean pesticides and preservatives and toxins.

By that definition, your fruits and veggies are loaded with “bad chemicals”, too. They’re put there by nature. Plants are not just happy organisms that are here to feed us. They’ve evolved, too, in a natural world filled with plant parasites, plant predators, and other plants that want to steal their nutrients and sunshine. So plants have developed plenty of chemicals themselves that act as “natural” toxins to give them a competitive advantage over other organisms. Plants make all sorts of toxins and chemicals specifically to prevent fungal and parasitic attacks, to make them taste less appealing when fruit is unripe, and to make them taste more appealing when fruits ripen.

A classic study, from 1990, illustrated this well. Dr, Bruce Ames and colleagues found that 99.99% by weight of the “pesticides”—the chemicals that kill pests—that they found in foods were made by the foods themselves. For instance, cabbage, good old cabbage, contains terpenes (isomenthol, carvone), cyanides (1-cyano-2,3-epithiopropane), and phenols (3-cafffoylquinic acid.) Tasty! All of these, and far more (listed in table 1 of that link and pasted below), are naturally made by cabbage. So the cabbage can survive.

from Ames, et al 1990

from Ames, et al 1990

Adding up the measured quantities of residual synthetic pesticides and related chemicals, Dr. Ames’ team found that the quantity of naturally-occurring pesticides outweighed those added by farmers by 10,000 times. Yes, your veggies are loaded with pesticides. Nature put them there.

By the way—Dr. Bruce Ames is no gadfly. He developed the “Ames test” that remains in wide use to determine if a chemical is a mutagen (a potential carcinogen.)  He is a real scientist who cut his teeth long before we decided anyone can “do the research” with Google.

 

Truth 3. Natural pesticides are just as harmful as synthetic ones.

We have this romantic, idealized view of nature—it’s nice and filled with bluebirds. In truth, nature is a fearless, relentless monster that can kill you five times before you hit the ground. Every organism competes with every other organism for survival, using claws and teeth and toxins and poisons. Small pox is natural, and it wants to kill you (or wanted to kill you, until we killed it first). Lightning is natural, and volcanoes, and frostbite and starvation and tapeworms and malaria. The natural world and natural things have killed far more organisms than humans ever have or ever will.

But what about those man-made, synthetic chemicals—they’re not “natural”, so maybe they’re more harmful. Let’s ask Dr. Ames. From that same study, in 1990, he showed that of 52 of the natural pesticides he had found in natural food, 27 of them were documented carcinogens. Half of them. Ironically, the proportion of synthetic chemicals that he had found were mutagenic was also about half. In Ames’ study, he said:

We conclude that natural and synthetic chemicals are equally likely to be positive in animal cancer tests. We also conclude that at the low doses of most human exposures the comparative hazards of synthetic pesticide residues are insignificant.

That makes sense, actually—when you let go of that odd romantic view of nature, and realize that natural organisms evolve to compete, it makes sense that natural chemical defenses will be harmful, too. That’s why they exist. Organisms need chemicals to protect them from pests, and there’s no particular reason to think that the chemicals they invent are any more or less harmful than the chemicals we invent.

 

Truth 4. “Organic foods” have plenty of added pesticides and chemicals.

OK, you might say. But organic foods have no added pesticides or chemicals! Even if the added amount with conventional foods is tiny, why not avoid that tiny added potential risk?

Because organic foods do have added pesticides and chemicals. Plenty of them. Here’s a link from the US government to approved lists of allowed substances, things that can be added to foods that are labeled organic. It includes sub-lists, including “synthetic substances allowed for use in organic crop production”—tasties like copper oxychloride, lignin sulfonate, and sucrose octanoate esters. You may also enjoy browsing the section on “Non agricultural (nonorganic) substances allowed as ingredients in or on processed products labeled as ‘organic’ or ‘made with organic (specified ingredients for food groups)’.” I could list many more scary chemicals (diethylaminoethanol! octadecylamine!) and unpleasant-sounding food additives (catalase from bovine liver!)—but you get the point. Organic, inorganic, natural, synthetic—it’s all chemicals. Organic is not added-pesticide free, not even close.

 

So: despite what the self-appointed internet experts are telling you, chemicals cannot be avoided—and natural foods contain far more harmful and natural preservatives, pesticides, and “toxins” than we add ourselves. Let’s keep this whole “chemicals in food” scare in perspective. There’s no need to fear what you eat.

Food allergy “testing” is usually a bad idea

Posted March 23, 2015 by Dr. Roy
Categories: Nutrition, Pediatric Insider information

Tags: ,

The Pediatric Insider

© 2015 Roy Benaroch, MD

People like tests. You get numbers, and maybe a printout, and there’s science and blood and things just feels more… serious, when testing is done. You can picture Marcus Welby  (or perhaps a more modern physician), looking solemn, declaring “We’d better run some tests.”

Are medical tests magical and mysterious, and can they unlock the secrets of life? Usually, no. And among the worst and most misunderstood tests we do are food allergy tests.

A few recent studies illustrate this well. A review of about 800 patients referred to an allergy clinic found that almost 90% of children who had been told to avoid foods based on allergy testing could in fact eat them safely. The study, bluntly titled “Food allergen panel testing often results in misdiagnosis of food allergy” also found that the positive predictive value of food allergy blood tests—the chance that a positive test accurately predicted real allergy—was 2.2%. That much, much worse than the odds if you flipped a coin, and much, much worse than your odds of winning at a casino. If someone told you that a positive test was only correct 2% of the time, would you even do the test?

What about the other way of food allergy testing, with skin scratch or prick tests? A recent study about peanut allergy made big news when it turned out to show that early peanut exposure can prevent allergy. (This isn’t new news, by the way—I’ve written about that before. But I get fewer readers than the New England Journal of Medicine.) But hidden in the methods and statistics of that paper was another gem. The authors tested all of the enrolled babies for peanut allergy, at the beginning of the study. And most of the babies who “tested positive”, whether or not they then ate peanuts, did not turn out to be allergic. A true statement from the data from that study would be: If your baby tests positive for peanut allergy, your child is probably not allergic to peanuts.

Read that sentence again. Kind of makes your brain hurt, doesn’t it?

It is true that positive-tested kids were more likely than negative tested kids to be allergic—among the group with more allergies later (those who avoided peanuts), 35% of those who had positive tests developed allergy, versus 14% who had tested negative. But still, in either case, most of the kids who tested positive did not turn out to be allergic, whatever they ate or did.

The fundamental problem, I think, is that doctors either don’t understand or can’t seem to explain the difference between sensitization and allergy. None of these tests can actually test for allergy—they test for sensitization, which is different. We gloss over that distinction, and end up giving out bad advice. People should not be told to avoid food based on the results of allergy testing alone.

Bottom line: if you child eats a food without having a reaction, he or she is not allergic, and you should not do any testing for that food as a potential allergen. You should never do broad panels of “allergy tests”—they’re much more likely to mislead and confuse than to give useful information. Any food allergy testing that is done should only look at foods that seem to have caused reactions in the past, and even then any positive testing should be confirmed by what’s called an “open challenge.” Under safe conditions, usually under an allergists’ care, give the child some of the food to eat to see what happens. That’s the only real way to “test” for allergy.

Football helmets protect skulls. They don’t protect brains.

Posted March 16, 2015 by Dr. Roy
Categories: Medical problems

Tags: , ,

The Pediatric Insider

© 2015 Roy Benaroch, MD

A few weeks ago, I wrote about concussions—mild brain injuries caused by trauma. There’s increasing concern that repeated concussions—that is, repeated brain injuries—aren’t good. They can lead to depression, intellectual decline, movement disorders, and other kinds of symptoms that you’d expect from someone whose brain has been injured multiple times.

One tack that athletics departments are taking is to invest in more-expensive helmets. The idea has some appeal—wrap your head in something protective, and then you can bash it into things safely. But there’s a fundamental misunderstanding here. Helmets, the best helmets, can do a really good job at protecting your child’s skull from damage. But no helmet in the world has ever been shown to provide any protection for your child’s brain.

Think about it. The helmet protects the outside of your head, the hair, the skin, the eyes the cheekbones, all of those. People wearing helmets do not get lacerations of the scalp, and they don’t fracture their skulls, because the helmet protects these body parts from damage. But the brain, that is a very different story.

Your brain floats on the inside of your skull, enveloped in fluid. It gets injured not by directly smashing into someone else’s head, or into the ground, or into a windshield. The brain doesn’t strike your steering wheel and it doesn’t get hit by a hockey puck or a boxer’s gloved fist. What strikes your brain, and what causes the damage, is the inside of your own skull.

Picture this: you’re in a speeding car. You, your head, your skull, and your brain are all traveling 60 miles an hour when you swerve off the road into a concrete pole. Very quickly, you and your head stop moving—BAM, you’ve decelerated from 60 mph to zero in just a fraction of a second. If you’re lucky, your head is protected by snapping forward not into the windshield or your steering wheel, but into a relatively-soft air bag. Air bags do a great job to protect skulls and heads. But what happens to your brain? As smart as it might be, brains follow the laws of physics, too. It was just moving at 60 mph, and the thing carrying it, the skull, just stopped. The brain then slams into the front of the skull, from the inside, at 60 mph.

There is no airbag in there to protect the brain. In a car accident, the brain just slams into the inside of the skull. And in a football injury, the same thing happens—the helmet protects the scalp and the head, sure, but the brain still slams into the skull from the inside. Unless they figure out a way to implant a little helmet inside the head, between the brain and the skull, there’s nothing in there protecting the brain.

It’s worse, by the way. The really bad concussions—the most serious brain injuries—come from the brain slamming sideways into the side of the skull, or from rotational forces that shear the cortex, the top thinking part of the brain, away from the base (think of slapping a top from the side and watching it spin. Whee! Brain!) In any scenario, the physics are the same—forces act on the skull to change its motion, and the brain slams into the skull from the inside.

Good sports equipment is still essential for athletes, and I don’t mean to minimize what a good helmet can do. I don’t want poked out eyeballs or broken jaws or caved in skulls, either. But I’d also like to see a more-honest discussion of brain injury in sports, and what we can and cannot do to prevent and mitigate the effects of these injuries. We’re not getting honest info from the helmet manufacturers, that’s for sure.

Help fight childhood cancer, and help me get bald!

Posted March 10, 2015 by Dr. Roy
Categories: Medical problems

Heya fellow lovers of science and children! In a few days I’ll be getting my head shaved to help raise money to fight childhood cancer through St. Baldrick’s. It’s a great charity, and it’s a fun way to let the kids know we love them and would do anything to help.

As ya’ll know, I don’t take any advertisers, and I have no financial relationships or anything to disclose about drugs, medical products, or any of that lucrative endorsement stuff that could rake in the dough. I write and manage this blog just to ham it up, have a good time, and hopefully spread some solid info about children’s health. I don’t even accept donations to the blog (there is a “donate” link over there, but it’s just for show. As far as I know no one has ever clicked it.)

If you’ve ever felt that this blog is a useful resource and wanted to thank me by tossing over a few dollars, why not click this link and donate to St. Baldricks? You’ll help children with cancer, and you’ll get a glowy feeling inside. I’ll end up with less hair. It’s a win-win!

Get ready for spring! Allergy therapy update, 2015

Posted March 9, 2015 by Dr. Roy
Categories: Medical problems

Tags: ,

The Pediatric Insider

© 2015 Roy Benaroch, MD

In last year’s Pulitzer Prize winning* post, I reviewed the medications available for treating the symptoms of spring allergies—antihistamines, nasal sprays, prescription and non-prescription goodness. There’s some new information and changes this year, so it’s time for an update!

First, a study just published provides more reassurance about the use of topical nasal spray steroids and growth. About 220 kids aged 3-9 were randomized to receive placebo nasal spray or intranasal triamcinolone (sold OTC as “Nasacort”), and their growth was followed before, during, and after treatment. Growth when the medication started was very slightly slower (by about an eighth of an inch a year), but that difference was quickly erased by catch-up growth after the medication was stopped. In typical practice, these medicines aren’t used year-round anyway. Bottom line: if there is any effect on growth, it’s insignificant, and it’s temporary.

We’ve also got the first FDA-approved sublingual allergy immunotherapy tablet to come to market. Sold as “Grastek”, taken regularly this can help children and adults overcome allergy to one specific plant, Timothy Grass. Downside: it takes a long time to “kick in”, and it only protects against this one specific pollen—when usually, people with polen allergies are allergic to multiple things. So I’m not sure just how useful this is. Still, it’s an interesting foot-in-the-door for home immunotherapy without the shots. I’m sure we’ll be seeing more of this kind of thing.

Here’s the rundown on all of the other medications, updated for 2015:

Antihistamines are still very effective for sneezing, drippy noses, and itchy noses and eyes. The old standard is Benadryl (diphenhydramine), which works well—but it’s sedating and only lasts six hours. Most people use a more-modern, less-sedating antihistamine like Zyrtec (cetirizine), Claritin (loratidine), or Allergra (fexofenidine.) All of these are OTC and have cheapo generics. They work taken as-needed or daily. There are still a few prescription antihistamines, but they have no advantage over these OTC products. Antihistamines don’t work at all to relieve congested or stuffy noses—for those symptoms, a nasal steroid spray is far superior.

Decongestants work, too, but only for a few days—they will lose their punch quickly if taken regularly. Still, for use here and there on the worst days, they can help. The best of the bunch is old-fashioned pseudoephedrine (often sold as generics or brand-name Sudafed), available OTC but hidden behind the counter. Don’t buy the OTC stuff on the shelf (phenylephrine), which isn’t absorbed well. Ask the pharmacist to give you the good stuff he’s got in back.

Nasal cromolyn sodium (OTC Nasalcrom) works some, though not as strongly as prescription nasal sprays. Still, it’s safe and worth a try if you’d rather avoid a prescription.

Nasal oxymetazolone (brands like Afrin) are best avoided. Sure, they work—they actually work great—but after just a few days your nose will become addicted, and you’ll need more frequent squirts to get through the day. Just say no. The prescription nasal sprays, ironically, are much safer than OTC Afrin.

Nasal Steroid Sprays include OTCs Nasacort and now OTC Flonase. There are also many prescription products, like generic fluticasone, Rhinocort, Nasonex, Nasarel, Veramyst, and others. All of these are essentially the same (though some are scented, some are not; some use larger volumes of spray.) All of them work really well, especially for congestion or stuffiness (which antihistamines do not treat.) They can be used as needed, but work even better if used regularly every single day for allergy season.

Antihistamine nose sprays are topical versions of long-acting antihisamines, best for sniffling and sneezing and itching. They’re all prescription-only (though they’re super-safe). They’re marketed as either the Astelin/Astepro twins (Astepro came out later, when Astelin became available as a generic; it lasts longer) or Patanase.

Bonus! Eye allergy medications include the oral antihistamines, above; and the topical steroids can help with eye symptoms, too. But if you really want to help allergic eyes, go with an eye drop. The best of the OTCs is Zaditor, which works about as well as rx Patanol, which they’re trying to replace with rx Pataday.

 

* That post didn’t win a Pulitzer. Does anyone read these footnotes?

What your kids do affects how their brains grow

Posted March 2, 2015 by Dr. Roy
Categories: In the news

Tags: , ,

The Pediatric Insider

© 2015 Roy Benaroch, MD

A short study to review today—from Pediatrics, November 2014, “Cortical thickness maturation and duration of music training: Health-promoting activities shape brain development.” Researchers looked at MRIs scans of healthy children that were being obtained as part of a larger study of normal brain development, correlating the development of several brain areas with musical training. They found that as kids age, the ones taking music lessons had more rapid growth and maturation of brain centers involving not only motor planning and coordination, but also emotional self-control and impulse regulation.

When you exercise a muscle, it grows bigger and stronger. The same thing, essentially, happens in the brain—but it’s more complicated, because different parts of the brain do different things. What this study confirms is that at least with music, the areas of the brain exercised with musical training become “stronger”—or, at least, larger and thicker, which in brain-terms means more effective. The authors speculate that conditions like ADHD, where those same areas of brain seem relatively under-functioning, might be helped by learning to play a musical instrument.

Think about the bigger picture, too. Whatever your kids are doing, that’s the area of the brain they’re exercising. If they’re reading, they’ll become better readers; if they’re playing tennis, they’ll get better at seeing and hitting a little fuzzy yellow ball. If video games are their main hobby, they’ll get better at making fast decisions and moving their hands quickly. Katy Perry fans will get good at dancing like sharks. You get the idea. At the same time, kids who don’t practice the self-control needed to learn a musical instrument might be missing out on at least one way to help their brains mature.

Get practicing!


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