Goodbye, Benadryl – it is time for you to retire

This has become, by far, the most-discussed and most-hated post that I’ve ever written. In retrospect I should have been much more explicit: I’m talking here about using Benadryl as an antihistamine to treat allergic disease. A follow-up post includes about 10 links to well-supported, recent guidelines that support my contention that Benadryl is not a good choice to treat allergic disease. Newer agents are faster, more effective, and safer. 

 

The Pediatric Insider

© 2019 Roy Benaroch, MD

Sometimes, old ideas and time-tested treatments remain the best. Newer doesn’t always mean better. Except, in the case of tried-and-true Benadryl. It is time for that old drug to be retired, sent off to pasture, and never used again. Goodbye, Benadryl. Fare thee well, adieu, and don’t let the door hit you on the way out.

Benadryl (diphenhydramine) was introduced in 1946. The top single that year was Perry Como’s “Prisoner of Love,” and, with all due respect, neither has aged well. Back in 1946, medicines like Benadryl didn’t have to pass the stringent safety and efficacy standards now required. And there’s zero chance, today, it would every have been approved for over-the-counter sale – and even if it made it as a prescription medicine, it would be plastered with warning labels.

tl;dr: Newer & better alternatives to treating any allergic disease are cetirizine (Zyrtec), loratadine (Claritin), and fexofenadine (Allegra). These are all safer, faster, and more effective. There is no situation where Benadryl is a better choice as an oral medication. No one should be using Benadryl for anything.

 

Benadryl isn’t safe

Benadryl causes significant sedation. One study in a driving simulator showed an ordinary adult dose of Benadryl caused worse driving than a blood alcohol level of 0.1% (that’s fairly drunk, probably between buzzed-drunk and frat-party drunk). Ordinary doses of Benadryl can also commonly cause urinary retention, dizziness, trouble with coordination, dry mouth, blurry vision, and constipation.

But more importantly, in an overdose Benadryl becomes very dangerous. It has caused respiratory depression, coma, heart arrythmias, and death in children and adults, and in doses that aren’t super-high. This is not safe stuff to have in the house with an exploring toddler, or in a teenager who might help themselves to whatever is in the medicine cabinet.

 

Newer alternatives are much safer

In the 1980’s, newer-generation antihistamines were introduced. At first, they required a prescription and were crazy-expensive; now, the best of these are cheap, generic, and easily available OTC.

These medicines were developed to address the serious safety concerns of Benadryl and other older antihistamines. They do not cross the “blood brain barrier”, cause minimal if any sedation, and don’t cause nearly as many of the other side effects. And, bonus, they’re not very dangerous even in massive overdoses. A recent review quoted that there has never been a death even in instances of up to 30 times the recommended dosing.

 

Newer alternatives are more effective, act more quickly, and last longer

In a serious allergic reaction, we want a treatment that’s quick and effective. Keep in mind that in the case of anaphylaxis, the most serious allergic reaction, antihistamines are NOT the correct, first-line treatment. Anyone experiencing an anaphylactic reaction, which can include a loss of consciousness, trouble breathing, and widespread hives and flushing, should immediate and without hesitation be given epinephrine by injection. Epinephrine should never be delayed while looking for or preparing an antihistamine. Antihistamines do not save lives. Epinephrine does. Keep your eye on the ball.

But for more-mild allergic reactions, like simple hives, an antihistamine is a good idea. And some docs still prefer Benadryl, since it’s been around forever. But the newer drugs are much more effective. They begin working more quickly, they are more effective at controlling symptoms, and they last much longer – so symptoms are less likely to return. And, bonus, since side effects are minimal, doctors can safely prescribe regimens even up to four times the labeled doses for specific indications (this has been studied extensively). For routine use, follow the label instructions – talk to your doctor if that’s not working, or if you think a higher dose is needed.

 

Benadryl and its generics (diphenhydramine and many combo meds) are still very popular sellers, and many docs and nurses still recommended it. This is just out of habit and inertia – there is no good reason, under any circumstances, where Benadryl is the right choice when an oral antihistamine is needed. It’s not 1946. It’s time for Benadryl to be permanently taken off the market and relegated to the history books.

Recurrent vomiting in a baby – could it be FPIES?

The Pediatric Insider

© 2019 Roy Benaroch, MD

Not every diagnosis is easy, and not every diagnosis can be made correctly from a first impression. FPIES is one of those tricky ones, and parents and docs can get it right by paying attention to clues and keeping an open mind. Let’s start with a story, and then we’ll talk about FPIES (hint: these are not the kind of PIES you want to eat!)

5 month old Sally has had two trips to the emergency department and one to her pediatrician for vomiting episodes. Each time, she has a sudden onset of vomiting, diarrhea, and lethargy, and gets sick quickly – twice she ended up needing IV fluids. She recovers in a few days and seems to feel better. Overall she’s usually a happy baby, but her weight has been concerning. She’s not growing as fast as she should. Sally attends day care and has two older siblings.

What do you think? Vomiting illnesses are very common, and they’re usually caused by viruses (like Norovirus, especially this time of year.) If there had been one or two episodes like this, and Sally otherwise seemed OK, the story wouldn’t necessarily seem unusual. After all, she’s in day care, and probably is exposed to a lot of yuck.

But, still, there are some clues that there’s more to this story. Most vomiting illnesses do not require IV fluids – Sally’s needed that twice. And overall her weight isn’t great. Could there be a connection?

Making a medical diagnosis is like detective work. First collect the clues (which are almost always in the story), then find a diagnosis that fits. But keep in mind that every diagnosis is a “work in progress” that may have to change as new facts come it. Sally seemed like she had a viral gastroenteritis (a “tummy bug”), until the story continued to unfold. I warn medical students and residents: don’t lock yourself into a diagnosis. Stay curious!

Sally’s “mystery” diagnosis turned out to be “FPIES”, or “Food Protein Induced Enterocolitis Syndrome.” It’s a rare-ish allergic condition usually affecting young babies and toddlers, who react to certain foods with episodes of intense vomiting, often with diarrhea. Sometimes FPIES can be more of a chronic presentation, including lower-grade, ongoing symptoms like poor growth. Common triggers include cow’s milk and soy, but also grains like oats and rice. There’s no test for FPIES – ordinary ‘allergy testing’ is often misleading – so the diagnosis rests on the story.

The prognosis for PFIES is very good. Children usually outgrow it. The trick is making the diagnosis early, so parents can avoid the trigger food(s). And the key to making the diagnosis is paying attention to the clues your patients and their parents are trying to tell you.  I tell my medical students and residents: stay curious and pay attention!

More about FPIES

Interested in learning more about how doctors think, and how the best diagnosticians work through the clues to figure out the answer? I’ve made three courses about this, available from The Great Courses, in audio or video formats. They can be watched or listened to in any order. You can buy ‘em (money back guarantee!), or stream them from TheGreatCoursesPlus.

• Medical School for Everyone: Pediatrics Grand Rounds – Pediatric mystery cases for you to solve – get in the mind of a pediatrician! (Me!)
• Medical School for Everyone: Emergency Medicine – Fast-paced mystery cases from the ED – and in this course you get to juggle multiple cases at once. Stay on your toes!
• Medical School for Everyone: Grand Rounds Cases – Step by step, hear the story, listen for the clues, and figure out the case! (This was my first course, and it covers a broad range of medical cases.)

Allergy Myths – don’t be fooled!

The Pediatric Insider

© 2018 Roy Benaroch, MD

Allergy issues are a big problem – both food and environmental allergies cause quite a bit of misery, and sometimes serious health problems, too. But there are a lot of myths swirling around the world of allergy, too. It’s time for a pop-those-myths listicle!

#1 WRONG: Food allergies are common

Many people think they’re allergic to foods, but rigorous studies using the best, most reliable diagnostic tools find food allergies to be present in about 2-8% of the population. Most of these reactions are mild. True, life-threatening food allergies are quite rare—in the United States, about 150 people die each year from food allergies, which is only a little higher than the number of people struck by lightning.

But: food allergy rates are rising, and we don’t want to be too complacent. When allergies do occur, they can be serious. The best approach is good, science-based prevention, evaluation, and treatment.

 

#2 WRONG: Most reactions to food are allergies

An allergy refers to a specific kind of reaction, most commonly hives or wheezing. Other, more common reactions include lactose intolerance (an inability to digest milk sugar, leading to abdominal cramps and diarrhea) and gastroesophageal reflux related to spicy or acidic foods. The distinction is important because rare, very serious allergic reactions can occur. If the reaction was not allergic in nature, it will not be life-threatening if exposure occurs again.

 

#3 WRONG: Most reactions to medicines are allergies

The most common adverse reaction to a medication is a rash, but these are usually not caused by allergy (the only common truly allergic rash is hives, which are raised, itchy areas that move about the body.) Most people labeled as “allergic” to penicillin are not in fact allergic, and can safely use this medication. Only a careful history and exam can determine this—there is no accurate test to confirm or refute true drug allergies. If you or your child is thought of as drug allergic, review the exact circumstances with your physician to see if it is a good idea to try the medication again (do NOT do this on your own!)

 

#4 WRONG: People who are allergic to a medicine should never take it again

Certainly, if a life-threatening reaction occurred you need to be very careful. And be much, much more wary of medications given as a shot or intravenously (I’m not sure anyone has ever died as a result of an allergic reaction to oral penicillin.) But unless the reaction was a true allergic reaction, usually manifested by hives or wheezing, a medication can usually be given safely in the future (again, do NOT do this on your own!)

 

#5 WRONG: People with egg allergy shouldn’t get a flu or MMR vaccine

Flu vaccines are safe in people with egg allergy – great studies have proven this. People with egg allergies can get routine flu immunizations, and are not at elevated risk of reactions (this is reflected in current guidelines – if anyone tells you differently, they’re not keeping up with the science.)

And egg allergy was never a contraindication to MMR. That was a myth. MMRs can safely be given to anyone with egg allergies.

 

#6 WRONG: Allergy testing can tell you if a child is allergic to something

Hoo boy, doctors misunderstand this one, too. The way to know if a person is allergic is entirely in the history: do symptoms of allergy occur upon exposure? If they do, that’s allergy; if they don’t, that is not allergy. If the history is clear, the diagnosis is nailed, done, confirmed, and set. No tests are needed; in fact, tests are quite likely to confuse the picture.

Allergy tests are for when the history is not clear, to help separate exposures that are “likely” from “less likely”, so that further history can be explored and attempts at avoidance attempted to see what the response is. Allergy testing, either with blood tests or skin testing, is far too inaccurate to be used in any other way.

Be especially wary of web-based labs that promise extensive “sensitivity” testing to investigate vague symptoms like weight gain, abdominal pain, low energy, fatigue, and behavior problems. These symptoms are not caused by allergy, though fraudulent testing will inevitably lead to false positives and incitements to purchase detoxifying supplements. This is expensive quackery. Stay away!

 

#7 WRONG: Hives are usually caused by allergies to foods

In adults, this might be true; but in kids, hives are more often triggered by minor infections than by food exposures. Sure, if there are hives you ought to think about potential new foods, and if there is a correlation you ought to look into that. But in the majority of cases in pediatrics, isolated or even recurrent episodes of hives are not from food allergies.

 

#8 WRONG: Specific allergies run in families

“Don’t give him penicillin! Mom’s allergic!” While the predisposition to allergies, asthma, and hay fever run in families, it isn’t to the same specific trigger. Junior has a mom with shrimp allergies? That means that he might more likely have food allergies of his own, but not more likely to shrimp than to peanut or egg or anything else. Same for medication allergies.

 

#9: WRONG: The best way to avoid food allergies is to avoid or delay giving the food.

This is an old myth that won’t die – but it’s completely wrong. In fact, it’s backwards. One of the best ways to prevent the development of food allergies is to start complementary foods between 4-6 months of life, and to quickly give a wide variety of all foods (avoid honey and anything that’s a choking hazard.)

 

If your physician is telling you myths from the above list, it’s time to ask for a referral to an allergist to get the best information. If it’s an allergist tell you one of these myths, well, I’m stumped.

Adapted from an earlier post

Don’t waste your money on “food sensitivity” tests

The Pediatric Insider

© 2018 Roy Benaroch, MD

Ah Facebook. Where else could I stumble on a video of a baby hippo taking a bath, or Toto’s Africa performed on solo Harp? But among the shares and silliness and talent, there’s a dark side to Facebook. It’s become a fast way for quacks to push their scams and empty your wallet.

Just today in my feed I received a “promoted” post about a “Food Sensitivity Test”. I’m not going to link directly to the company – feel free to do a Google or Facebook Search, you can find them along with dozens of other companies that push a similar product. What they’re selling, they claim, is an easy, at-home test that will reveal your “food sensitivities”.  They say their test won’t diagnose allergies (which is absolutely true), but it will help you find out which foods might be causing things like “dry and itchy skin, other miscellaneous skin problems, food intolerance, feeling bloated after eating, fatigue, joint pain, migraines, headaches, gastrointestinal (GI) distress, and stomach pain.”

This is absolute nonsense. Their test can’t in any way determine if any of these symptoms are possibly related to food. What they’re testing for in your blood, they say, are IgG antibodies that react to each of 96 different foods in your body. But we know that these IgG antibodies are normal – all of us have some or most of these if we’ve ever eaten the food. IgG antibodies are a measure of exposure, not a measure of something that makes you sick or makes you feel ill. Having a positive IgG blood test for a food means that at some point you ate the food. That’s it. Nothing more.

This isn’t something that we just now discovered. IgG antibodies to food have been a known thing for many years. We know why they’re there and we know what they do. And we know testing them is in no way indicative of whether those foods are making you sick. Recommendations from the American Academy of Allergy Asthma & Immunology, The Asthma and Allergy Foundation of America, the American College of Allergy, Asthma, and Immunology, and the European Academy of Allergy and Clinical Immunology all unequivocally recommend against food IgG testing as a way to evaluate possible food sensitivities. The testing just doesn’t work to reveal if a food is making you sick.

But that doesn’t stop quacks from direct-marketing on Facebook. If you’re offered IgG-based food sensitivity testing, either through the mail, at a physician’s, or at a chiropractor or naturopath, I’ll tell you exactly what it means: Save your money and run the other way. Whoever is pushing the test is either deliberately deceiving you or doesn’t understand basic, medical-school level immunology. It’s a scam.

More details about the (lack of) science behind IgG food testing

What’s the best peanut policy to prevent severe allergic reactions in schools?

The Pediatric Insider

© 2017 Roy Benaroch, MD

Peanut-free schools, peanut-free rooms, peanut-free tables – they’re all an effort to protect children who have severe peanut allergies from accidental exposures. We’d all like to make sure our school are as safe as possible for everyone. So what’s the best policy on peanuts and tree nuts?

A study in press at the Journal of Allergy and Clinical Immunology adds some science to the debate.  Researchers looked back at peanut allergy experiences at Massachusetts public schools from 2006-2011. They polled every public school from K through 12 to determine their “peanut policy”. Though the response rate was only about 55%, the policies varied a lot – from completely no-serve, no-bring peanut schools (about 2-3%), to no peanuts allowed from home (about 10%), no peanuts served by the school (60%), to keeping some classrooms peanut free (70%), to having designated “peanut free tables” in the cafeteria (this was the most common policy in place, accounting for about 90% of the schools). (Some schools had multiple policies, so the numbers are > 100%). The peanut policies remained about the same for the 5 years of the study, and didn’t vary too much from elementary to high schools.

Data was also collected on every episode at school where epinephrine was administered. Epinephrine is the drug given to treat a serious allergic reaction (that’s the medicine in those weirdly expensive Epi-pens.) It turns out that Massachusetts schools must file a form when epi is given, so those were easy to track. Over the 5 years, epinephrine was given to children having an allergic reaction to peanuts in Massachusetts public schools about 20-40 times per year, with a modest increase from year-to-year during the study. We’re not talking huge numbers, here. Epinephrine administration was used as a “proxy”, or substitute number, for the actual number of peanut reactions in the schools – though it’s possible that epi was sometimes given when it wasn’t indicated, or sometimes was withheld when it should have been given.

The results are interesting. Of the peanut policies in place, the only one associated with a significantly decreased number of epinephrine uses was the presence of peanut-free tables in eating areas. Other policies, including having an entirely peanut-free school, did not result in fewer instances of epinephrine use. In other words, a school with a policy to be completely free of peanuts didn’t seem safer for peanut-allergic kids than a school that allowed peanuts to be brought from home.

These results aren’t super-strong. The number of serious reactions was small, and the number of absolutely peanut-free schools was small, too. There were only two nut reactions in the peanut-free schools (and one of them was in a boy that brought his own walnut cookie from home, despite being known to be walnut allergic.) When you crunch the numbers, the per capita chance of reactions in nut-free schools was actually higher than in schools with less-restrictive numbers, but with numbers so small I don’t think you can hang your hat on that conclusion.

A few lessons can be learned from this study. Even among schools that claimed to be “peanut free”, many allowed peanuts to be brought from home. Schools should have clear policies that make sense to parents. It’s also clear that even truly peanut-free schools aren’t a guarantee that no peanut exposures will occur—schools shouldn’t just declare no nuts, and leave it at that.

I wonder if the relative superiority of peanut-free tables is because that policy is easier to enforce. When an entire school is meant to be “peanut free”, you might be more likely to have some families break the rules. Also, “peanut free” policies might lead to a false sense of security among children who are nut allergic. They still have to watch what they eat. This study didn’t look into these factors, or how well peanut policies were enforced, or exactly how children were exposed in every instance.

Allergic reactions to peanuts are not common in schools, but when they do occur they can rapidly become life-threatening. Avoidance of exposures is the main way to treat peanut allergies; and when a serious reaction does occur, epinephrine should be given immediately. Beyond that, we just don’t know what the most-effective school policy should be. This study gives us some insight, but we’ve still got more to learn.

 

edit: Here’s a tangentially-related, sickening story about the apparent hazing of a peanut-allergic college student. What the hell is wrong with people? Accidents happen, but this is just…. just… I have no words.

 

 

 

Epipen alternatives – there are cheaper options

The Pediatric Insider

© 2016 Roy Benaroch, MD

Epipens have gotten crazy expensive, yes — $600 for a two-pack. Here are some alternatives that might help you save a few bucks.

#1: Wait a few weeks, and see what Mylan does. Mylan, the company that makes the “Epipen” brand of epinehphrine auto-injector, has been under a lot of pressure lately to back off their unseemly price gouging. They’ve introduced a savings card that claims to lower your out-of-pocket expense to no more than $300 dollars, and say they’ve expanded eligibility for their patient assistance program for their less-wealthy-yet-still-allergic patients. Just yesterday, they accounced a new generic version of their own Epipen, claiming it will be identical to the genuine Epipen, but at half the price. Weird, yes, selling two things that are identical (other than the price), but I suppose stranger things have happened. Give Mylan a few more weeks, and they’ll probably start giving away Epipens in cereal boxes.

#2: Find out if you really need to have an Epipen available for your child. Epipens, until recently, weren’t prescribed for many children. A robust marketing program from Mylan (including appearances by Sarah Jessica Parker on daytime talk shows) along with an expanded FDA indication for people at any risk for allergic reactions turned a niche product into a billion-dollar moneymaker – and that was before they raised the prices through the roof. A reasonable question: are all of those Epipens really necessary? Certainly, those who’ve had a life-threatening allergic reaction to a food or bee sting in the past need one available. And high risk patients (for example, those allergic to peanuts who also have a history of asthma) clearly need them, too. But what about people allergic to other foods, who’ve had multiple reactions in the past, but never anaphylaxis? What about the many people who’ve tested positive for allergic sensitization, but have never actually had any reaction at all? Doctors are loathe to withdraw an Epipen recommendation (better safe than sorry!), but there are times when all of this money could be better spent in another way. If you’re not sure if or why your child needs an Epipen prescription, ask your doctor to review this with you before you refill it.

#3: Hold on to expired Epipens, at least for a little while. Epipens keep at least some potency beyond their expiration dates, especially if they’ve been stored in a cool place. Don’t discard your old Epipens until you’ve purchased new ones – it’s better to use an expired Epipen than to have no epinephrine available when needed.

#4: Consider the Other Brand, “Adrenaclick”. Epipens have pretty much flooded and dominated the market, but there is another epinephrine auto-injector out there, the “Adenaclick.” Instructions for using it are a little different, so if you get one make sure you’re familiar with it. A two-pack lists for $140 less than Epipen, and you can get that price even lower by using a coupon from GoodRx.com. Even better: there is a generic Adrenaclick out there, and it’s even cheaper if you can find it (supplies, I’m told, are limited.) To get an Adrenaclick or the generic version, you need a specific prescription from your doctor listing this by name. In most states, pharmacists cannot substitute Adrenaclick for an Epipen. You’ll want to check your insurance formulary, too – the list prices may not matter as much as what “tier” these products fall under for your plan.

Expired Epipens – Safe to use?

The Pediatric Insider

© 2016 Roy Benaroch, MD

The sticker shock for Epipen purchases has some people wondering: Do I really have to buy a new one every year or so? Does it really matter if the drug has aged past its expiration date?

An Epipen is a device that automatically injects epinephrine. It is The Drug for potentially catastrophic allergic reactions to things like foods or bee stings. If someone’s having a bad reaction, epinephrine can save a life. In a medical situation, we’d typically draw up epinephrine from a little vial (which is way cheap, less than 5 bucks) and inject it into an available big muscle. Presto, you’re in the clear (it really can work super-quickly. Quite satisfying.) Since it’s awkward and perilous to draw up epinephrine into a syringe while you or your child is dying of an allergic reaction, for home use an automatically-injecting device is prescribed. Handy! Just remove a cap, press against the skin, and a little spring loaded mechanism fires off, poking out the needle and injecting the medicine in one E-Z step.

Those autoinjectors were first developed by the US military for treating nerve gas attacks. By the mid-1970’s a home version for allergies came out, and though the company that developed it has changed hands, merged, and moved on, the thing that’s currently sold uses pretty much the same technology. The medicine in there, epinephrine, is (and has been) dirt cheap for decades. What makes an Epipen expensive is the device used to inject it, which is currently protected by both patent law and an FDA that seems keen on making sure it’s the only widely available brand. Free from any competition, and with sales buoyed by aggressive marketing, by the manufacturer has been jacking the price through the roof.

Making this even more expensive: a newly purchased Epipen has a manufacturer’s expiration date, typically less than 2 years after purchase. So what happens after that date? Does the medicine really “go bad”?

There aren’t a lot of studies about this. I found two (thanks very much to the Simons, both F. Estelle and Keith, from Winnipeg, Canada – they’re authors on both papers!) In May, 2000, the Simons examined 34 donated Epipen injectors, administering them to 6 New Zealand White rabbits (not at the same time.) The out-of-date injectors delivered less epinephrine, and the drop was proportional to the age past expiration. The older the device, the more it lost its punch. Still, eyeballing their data in Figure 2, devices that were less than 24 months past expiration had between 60-90% of their drug intact, which isn’t terrible. They concluded that as long as the epinephrine wasn’t visibly discolored or damaged, it was better to use an expired Epipen than nothing at all.

Those same authors (with a few extra friends, minus the rabbits) looked at expired Epipens again in 2015, measuring potencies of 80-100% in devices up to three years past their expiration. Again, not too shabby.

Epinephrine is especially vulnerable to breaking down in heat. Epipens stored in car glove boxes aren’t going to last. And the auto-injecting mechanism, while robust, isn’t made for kickboxing practice or roller coaster festivals.

Still, for ordinary households who try to keep their Epipens in a cool, the devices  probably keep at least some potency somewhat past their printed expiration dates. It’s best if families replace them after they expire, to make sure they’re getting a full and reliable dose. But if someone needs a dose of epinephrine, and the only Epipen you’ve got is expired – use it.

And when you do buy a new one, make sure to ask the pharmacist to give you the new stuff, even if she has to reach way in the back. Since they’re so expensive, it might even be worth it to call around a few places, to see whose stock is the freshest.

More about drug expiration dates

The myth of iodine allergy

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.

It 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.

Refs:

http://www.ncbi.nlm.nih.gov/pubmed/20045605

http://www.ncbi.nlm.nih.gov/pubmed/16541971

Get ready for spring! Allergy therapy update, 2015

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?

Food allergy testing: Do those big panels work?

The Pediatric Insider

© 2014 Roy Benaroch, MD

Theresa asked about eczema (see last post), and also asked about food allergy panels. Does all of that testing help?

Well, usually, no.

It turns out that allergy testing (whether done by skin scratches or blood tests) doesn’t even test for allergy. We sort of smudge through that distinction, because it’s complicated. But it’s time for someone to spill the beans about this kind of testing, and here at The Pediatric Insider, we’re all about telling you guys “the real deal”—the inside info that docs typically keep to ourselves. Here’s something you may not want to hear: “allergy” testing is, well, just not very good.

Let’s start basic. An “allergy” is an adverse reaction (a bad thing, some kind of symptom) triggered by an exposure to something, and caused by a reaction of the immune system. It requires symptoms of some kind, and requires the symptoms to be caused by an immune reaction of some sort.

A broader term, “adverse reaction,” includes allergies but also non-immunologic reactions to things. For instance, many people get bloaty and gassey after ingesting milk. That’s typically caused by lactose intolerance, an inability to digest milk sugar that has nothing to do with any allergy. Still, lactose intolerance and gluten sensitivity and many other reactions are sometimes lumped in with allergies. They’re not allergic, and no “allergy testing” of any kind could possibly identify non-allergic reactions.

Also, allergy – an allergic reaction – requires some kind of symptom, and the symptom ought to be reproducible after exposures. Allergy “testing” often reveals “positives” to foods or other things that upon exposure doesn’t actually trigger a reaction. If eating a food you’ve tested positive for doesn’t cause a reaction, you are not allergic to the food. Period. Allergy requires symptoms.

And that’s the biggest issue with allergy testing—because these tests don’t test for allergy. They test for “sensitization”. They show that your immune system has the capacity to react to the substance, but that doesn’t necessarily mean that you will react to the substance.

I can’t tell you how many times I’ve heard from families who tested positive for food XX, though they’ve never had a reaction to XX—and in fact, they used to eat XX all the time. If your child eats peanuts routinely and doesn’t have a reaction, it doesn’t matter what the allergy testing shows. He is not allergic. The test shouldn’t have been done in the first place.

There are other problems with allergy testing. Though individual tests can fairly accurately say who is sensitized, each test does have a chance of a false result. If the rate of an incorrect test is, let’s say, 5%, that might sound pretty good. But what if you do a panel of 40 foods, each of which has a 5% chance of a false result? There’s a 88%* chance you’ll get at least one false positive. If the panel is large, you’re going to get false results. The larger the panel, the more wrong answers you’ll get. What then?

Another problem: there are a lot of ways to do allergy testing, and they’re not all the same, and I most families have no idea what they’re getting into. The current, most reliable blood testing for sensitivity is called a Cap-RAST or ImmunoCap, and it tests for specific IgE molecules. Older tests are far less accurate, and some still in wide use are as worthless as flipping a coin. If you are going to do allergy testing, you should at least do the best one. Skin testing, too, has different reagents and methods, and it can be difficult to know if what’s being done is the most-reliable testing.

About skin tests: they’ll be unreliable if the patient has been taking antihistamines, and they’ll be less reliable if the patient has a skin condition like eczema, which causes high overall IgE levels and a sort of overall hypersensitivity that leads to many false positives on both skin and blood testing. Testing children with eczema is fraught with peril, which is one reason many dermatologists aren’t keen on addressing the possible allergy-eczema connection.

Still, allergy testing can sometimes help, if you keep these points in mind:

• Consult with a board-certified, genuine allergist. Many companies market allergy kits and tests and things for general practitioners and ENTs and who knows who else. They’re a big money maker, but we really don’t know what we’re doing with them or how well they work. Please stay away from alt-med practitioners who claim to be able to diagnose allergies by holding your hands or waving vials about or using some kind of elecromagnetic hyperscience quantumconfusionating walletemptier.
• Test only for foods or other allergens that might be causing a reaction. Foods that are eaten routinely without problems are NOT allergies (and testing will lead only to confusion); foods that always do cause a reactions ARE allergies, and don’t have to be tested. Only test the grey-zone, “maybe” foods, or you’re asking for trouble.
• Test a limited number of foods. Almost all food allergies are to a small number of candidates: milk, egg, wheat, soy, shellfish, fish-fish, peanuts, and treenuts. Tests for mustard and plantain and okra and lamb are unlikely to yield useful results, and might upset the lambs.
• Think of allergy testing as a starting point, for clues to what might be a real allergy (positive tests), and clues for what are probably not causes of allergy (negative tests.) Under most circumstances, unless there’s been a life-threatening reaction, you have to confirm ‘allergy testing’ with deliberate exposures. And if there has been a life-threatening reaction, you probably already know what the trigger was—so why do the test?

* It has been a long time since I did statistics. What I did was figured the 5% chance of a false result on one test means that 19/20 times the test will be correct. So if you’re doing that 40 times I figure the chance of 40 correct tests in a row is 19/20 raised to the 40^th power = ~ .12, and the chance of that not happening is 1-.12 = 88%. Am I even close? At The Pediatric Insider we welcome comments that point out boneheaded mistakes. Be gentle.