Archive for the ‘Medical problems’ category

Serious side effects of vaccines are rare. What does that mean?

October 1, 2015

The Pediatric Insider

© 2014 Roy Benaroch, MD

Since every second of my life, and then some, seems preoccupied with the transition to the New and Improved ICD-10 code set — I can’t imagine how I lived so long without being able to code for macaw attacks – I’ve had no time to write anything new. So today you get a refurbished, classic post. And by classic, I mean old. I put a new photo somewhere in the text to freshen it up, so I promise it’s worth a read. Enjoy!

“Serious side effects of vaccines are rare.”

Vaccines are not 100% safe. Like any medical intervention, there’s some risk (honestly, like anything at all, anything we do, there’s some risk. But let’s not get sidetracked here.) Side effects, including serious side effects, can happen after vaccines. What are these reactions, really? How often do they occur?

Here, I’m only talking about genuine, established side effects. Things are genuinely, scientifically, reliably linked to vaccines. Some things that had once been thought be a potential side effect of vaccines are now known to have been caused by other conditions (like seizures and encephalopathy after DTP, now known to be most-often caused by a rare genetic condition called Dravet Syndrome, that would have occurred whether the child was immunized or not.) There are also side effects reported that are clearly unrelated, like choking on a bean in the trachea or turning into the Incredible Hulk. We’ll ignore those, and concentrate on the real, serious, potentially deadly side effects that have been documented to be caused by vaccines. I’m going to list all of them, for every vaccine.

Any vaccine – Serious allergic reactions can occur. These do happen, though the rate of serious reactions depends on the vaccine. For most immunizations, the rate is less than 1 in 1 million; however, some very-rarely used vaccines can have a higher rate. The yellow fever vaccine, for instance, causes severe allergic reactions in about 1 in 55,000 people; anthrax vaccine is estimated to cause severe reactions in 1 in 100,000. Almost all severe allergic reactions occur within minutes of vaccination, and health care facilities who give vaccines should have people trained to treat rare reactions like these.

Influenza – The Pandemrix brand of influenza vaccine, which was never licensed or used in the United States, has been linked as a cause of narcolepsy in about 1 in 55,000 vaccine recipients in several countries in Europe. This product was only used during the 2009-2010 season. The CDC is currently sponsoring an international study to try to better understand this, and why that one formulation seemed to be a unique trigger for this rare condition.

In 1976, a different specific Swine Flu vaccine was linked to about 450 cases of Guillian-Barre Syndrome (GBS), a neurologic disorder that was estimated to occur in about 1 in 100,000 people who got that specific vaccine that year. The baseline rate of GBS is probably 1-2 per 100,000, so when 45 million doses of vaccine were given in 1976, some cases were going to occur coincidentally. Substantial studies have shown that other flu vaccines from more-recent years do not cause GBS. Ironically, influenza disease itself causes more GBS than even the 1976 Swine Flu vaccine is purported to have caused, and even if that association were true influenza vaccination would prevent far more GBS than it would trigger.

Japanese encephalitis – Rarely used in the United States, the Japanese Encephalitis vaccine has been linked to prolonged arm and shoulder pain among vaccine recipients. I could not find an exact rate, but this appears to be an uncommon reaction.

MMR — About 1 in 30,000 people given a dose of MMR will have a drop in their platelet count, which can predispose to bleeding. The rate of low platelets is much higher in real measles than after the vaccine, so, again, ironically MMR probably prevents more cases of low platelets than causes it. This condition is temporary and almost always requires no treatment at all.

Polio — The oral polio vaccine, no longer used in the United States, could trigger genuine, full-blown polio in some people—probably about 8 per year in the entire US, back when we used the oral version. We’ve been using only the injected polio since the mid-1990s, which carries zero risk of causing polio.

Rotavirus – Rotavirus vaccines carry a small risk of causing an intestinal blockage called “intussusception.” This condition is treatable, though it often requires a brief hospitalization. The risk was highest after the first doses of the original brand of vaccine, Rotashield, which was withdrawn from the market; the risk after current brands is probably in the range of 1-3 in 100,000. However, rotavirus itself, the real infection, is also a cause of intussusception. To put this in perspective: using the high end of the risk estimates, about 40-120 vaccinated infants may develop intussusception each year in the USA, compared to 65,000 infants who had been hospitalized for rotavirus illness each year prior to the vaccine becoming available.

Smallpox – Routine smallpox vaccinations stopped by 1970 in the US, but a smallpox vaccine is available for high-risk researchers and military people and others thought to be at risk of exposure. The vaccine can cause heart problems in 1 in 175 people, and there is a risk that the vaccine virus can spread on the skin of a vaccinated person or contacts, especially when the skin is damaged or there are immune problems.

Yellow fever – Used only in certain travelers, some kinds of typhoid vaccine can causes severe neurologic problems (about 1 in 125,000) or death, especially in elderly people (1 in 500,000).

That’s it—that’s the list. All of the serious, lasting, you-need-to-worry about side effects. You’ll notice that almost all of the really serious side effects occur only with vaccines that aren’t likely to be recommended for your children. Most of the routine childhood vaccines (DTaP, HIB, pneumococcal conjugate, hepatitis B, hepatitis A, chicken pox, meningococcal conjugate, human papilloma virus) only carry a very rare risk of allergic reactions, and even those are entirely treatable and temporary. In other words, science has failed to find any evidence for any real, lasting, serious vaccine reactions among any of the vaccines currently recommended for routine use in children in the United States.

When we say “serious side effects are rare,” we mean “serious side effects are very very very rare.”

This is an orcaWhat parents need to worry about are diseases, not vaccines. Don’t let the scaremongers and internet rumors sway you. The risk of a serious, lasting side effect from any routine childhood vaccine is just about zero. Make sure your children are safe and protected. Vaccinate!

The myth of iodine allergy

September 28, 2015

The Pediatric Insider

© 2013 Roy Benaroch, MD


Since every second of my life, and then some, seems preoccupied with the transition to the New and Improved ICD-10 code set — I can’t imagine how I lived so long without being able to code for macaw attacks – I’ve had no time to write anything new. So today you get a refurbished, classic post. And by classic, I mean old. I put a new photo somewhere in the text to freshen it up, so I promise it’s worth a read. Enjoy!


One of the goals of this site—along with soliciting donations and letting me write and publish goofy stuff—is to promote good, solid science-based medical information. If you’ve been around, you know I don’t go for made-up-stuff. And I especially don’t like it when it’s other doctors spreading the misinformation.

Have you had a reaction to intravenous contrast dye during a CT scan or other exam? Have you been told you’re allergic to iodine, and that you should avoid seafood?

Wrong wrong wrong. You’re not allergic to iodine. And you can almost certainly have seafood—you’re no more likely than anyone else with any allergy to be allergic to seafood, or salt, or dairy products, or anything else that contains natural or added iodine. The only thing you may need to avoid is that same kind of IV contrast dye in the future—though even then, it can probably be safely used with simple premedication.

Iodine is a natural element. It is essential for life—if you didn’t have any, your thyroid gland couldn’t work, and you’d get sick and die. Iodine is found especially in seafood, but also in some vegetables and dairy products (especially if the cows were grazing on land where the soil was rich in iodine.) In many countries, including the USA, salt is routinely fortified with iodine to prevent thyroid disease.

Allergies are almost always triggered by proteins—big, honking, complex molecules made of chains of amino acids—or other big molecules. Someone who’s had a reaction to IV contrast dye has not reacted to the iodine, but to the other constituents of the dye. People who’ve had these reactions may need to be premedicated or use a different, low-reaction type of dye is used in the future if they need further studies.

These are dangerous macawsIt may be that people who’ve had reactions to IV contrast might also have a food allergy, and that food allergy might even be to seafood. But there is no increased risk of seafood allergy than to allergy to any other foods. You might be allergic to seafood or milk or eggs or peanut or… nothing. But you’re not allergic to iodine.


Want kids to see better? Send them outside

September 24, 2015

The Pediatric Insider

© 2015 Roy Benaroch, MD

This month in JAMA, physicians from China reported a large, randomized trial – and it turns out that, at least in China, more outdoor time means fewer kids need glasses for nearsightedness.

About half of 1900 students from 12 schools were randomized to either get an extra 40 minutes of outdoor play each school day, or continue their usual routine. They were followed for three years and then assessed for nearsightedness, or myopia.

In the control group (with no extra outdoor time), 40% of the children were myopic by the end of the study; those who got extra outdoor time reduced their risk to 30%. The risk remained about the same when parents’ eyesight was factored in. And among children who were myopic at the start of the study, their vision worsened more quickly if they didn’t get the extra outdoor time.

It’s been observed that a lot of close-up work in young children seems to contribute to myopia. About 90% of young adults in the East Asian countries of China, Taiwan, and South Korea are myopic, compared to 20-30% in the UK. Rates have risen dramatically in these Asian countries as academic pursuits have begun to dominate their early educational experiences—and perhaps the close reading work, instead of playing outdoors, is to blame.

It’s not clear whether increased outdoor play would decrease myopia in the USA—but this is just one more potential plus for outdoor activities. Now stop reading and go outside!

Vision therapy for dyslexia and reading disorders

September 14, 2015

The Pediatric Insider

© 2015 Roy Benaroch, MD

Dyslexia is a specific learning disorder—a problem not with intelligence or a lack or trying, but with the ability of children to learn to read. It affects 3-20% of children (depending on the exact definition used). Because reading is essential to school success in almost every subject, problems with reading need to be addressed as early as possible.

One kind of therapy for dyslexia is based on the premise that reading problems are caused by vision problems—though the scientific community isn’t convinced that this is the case. The large, national professional bodies representing pediatricians, ophthalmologists, and optometrists recommend only routine vision screening for children having reading difficulties. Nonetheless, there’s a cottage industry of so-called developmental or behavioral optometrists who offer a variety of services commonly called “vision therapy” to help with reading problems and other developmental challenges. There is very little objective evidence that any of these therapies offer more than short-term improvement. Besides, they’re very expensive, and often not covered by medical or vision insurance. Parents need to know whether this kind of therapy is worth pursuing.

Researchers in the UK published a study in May, 2015, looking at a large number of children in a birth cohort from the early 1990’s. These children had all had thorough serial health assessments as they grew. For this specific study, they found that 3% (172 kids) in the birth cohort of 5822 children met objective criteria for reading impairment. All of these children had a very through vision evaluation, and most of those were completely normal; the small number of reading-disabled kids who weren’t 100% normal on their vision assessment had subtle abnormalities. The authors concluded “We found no evidence that vision-based treatments would be useful to help children with severe reading impairment.”

A strength of the study was that it was population-based—it didn’t just include children referred to a clinic because of problems. And the findings were objective and validated. However, the authors only looked at the most severe level of reading impairment. It’s possible they may have missed vision issues in less-affected children (though one would think, if vision were the root of reading problems, that the worst readers would have the most egregious and easily-identified vision problems.)

This study adds to the weight of evidence that “vision therapy” is unlikely to be useful for reading problems, and may be a waste of time and money.

Strep throats can usually return to school the next day

September 10, 2015

The Pediatric Insider

© 2015 Roy Benaroch, MD

A simple study published in August, 2015 has shown that starting antibiotics for strep throat in the afternoon means that your child can safely return to school the next day.

Physicians in Virginia recruited 111 children with strep throat, proven by rapid testing and culture. All received a single routine dose of amoxicillin. The next morning, about 90% of them had a negative strep culture—they had already cleared the bacteria. The authors conclude that children who begin treatment for strep throat by 5:00 PM may safely go back to school the next day, without fear of infecting classmates, as long as they feel better and have no fever.

(I’m honestly not sure why they threw in the lack of fever as a criteria. But I think most kids with fever probably still feel pretty bad, and ought to take another day off—so I don’t disagree with their conclusions.)

Though the study didn’t address this, parents still need to complete the full course of antibiotics. We know from many older studies that less than a full course of antibiotics increases the risks of complications from strep.

Simple, quick, and a straightforward and well-informed answer. Science!

The latest in autism research

August 31, 2015

The Pediatric Insider

© 2015 Roy Benaroch, MD

Science: it may not always be the fastest, coolest, or sleekest way to get from one place to another. And it certainly is prone to dead ends and tangents. But if you want to really understand what something is all about, real science and real research are your best tools. Some great examples come from a few studies that came out this year about autism.

A British study from May, 2015 (summarized nicely here) looked at sets of twins, looking not only at diagnosed autism but at autistic behavior traits. Bottom line: autism is very largely genetic, as demonstrated by the higher association of autistic traits in identical twins. Since sets of twins largely share the same environmental and family influences, looking at identical (ie sharing the same genes) versus fraternal (sharing genes only as siblings) is a well-established way to separate out genetic and environmental influences. Using Fancy Math, the authors conclude that autism’s roots are found in one’s biologic make-up at least 74% of the time, and perhaps much higher than that. Studies like this will help future researchers concentrate on the most likely candidates for autism’s cause.

Another cool study, this one from the University of North Carolina, took the role of genes even further. We know that about 1,000 genes have been linked to autism—meaning that certain variations are more likely to occur in individuals with autism. What these researchers did is take that further, finding the exact functioning of one of these candidate genes. They found that the gene encoded for an altered protein that incorrectly flags other proteins in a cell for destruction. This causes the appearance of what are called ‘spines’ on cells in the brain—and, sure enough, we already knew that these spines were more common in kids with autism. It’s like connecting a circle—you start by figuring out which genes are present in autism, then figure out what they do, then confirm that the result of having these genes is present in children with autism. That’s how we go from understanding why autism occurs (a change in a gene) to how it occurs. And once we know how it occurs, we can start working on reversing or stopping the process, to preventing the altered gene from causing problems.

Studio 54The internet is a noisy disco of flashy memes, slogans, and catchphrases. And, of course, ubiquitous Google searches ironically misunderstood as “research.” But those sorts of things don’t help anyone really understand what’s going on. Want to understand and help families with autism? Support the science, not the noise.

“The Science of Mom” – a great new book for parents

August 27, 2015

The Pediatric Insider

© 2015 Roy Benaroch, MD

New parents have access to plenty of information. Websites, Facebook pages, blogs, tons of stuff, all ready to answer any question. The problem is that many answers are just plain wrong. Not just “your-opinion, my-opinion” wrong, but flat out stinking lies of wrongness, repeated over and over, until one has to figure, hey, I saw that somewhere. I guess it’s true.

You don’t have to guess. If you want reliable and honest information, let me suggest a new resource: a book by Alice Callahan, PhD, called The Science of Mom: A Research-based Guide to Your Baby’s First Year. Dr. Callahan’s blog has been a favorite of mine, with solid, well-referenced, and very readable articles on parenting topics.

Her new book is organized into chapters covering many “hot topics” concerning a baby’s first year. There’s an introductory chapter that concisely explains how science can turn you into a better parent, and how to tell good science from bad. Other chapters cover topics both expected (vaccines, breastfeeding, sleep training) and unique (how newborns learn and interact with the world.) The breastfeeding chapter did a particularly good job presenting this nuanced subject – in fact, the science says more than just “breast is best.” Her chapters on sleep training and sleep safety were also very good, though I would have been even more direct about SIDS prevention. Still, that’s a style thing—she’s got the science down, solid.

Dr. Callahan isn’t bossy, and isn’t out to tell you what she thinks. Her book tells you what the science says, and explains how we know what we know, and what things we still need to learn more about. There’s humility and warmth, here, which I think parents of newborns will find reassuring. There are many “controversies” that you really don’t need to worry about.

This book is great for parents of newborns and babies, and I think it would make a very good gift for expecting couples. In the spirit of full disclosure, I got my copy for free (thanks!), though I’m planning to donate it tomorrow to my local little free library. Stop by Womack near ChamDun to grab my copy, or get it from Amazon or whatever. It’s good.