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Anyone ever tried year-round Claritin or Zyrtec as a preventative to mild (level 1 or 2) food allergic reaction?

I came upon some medical research a while back that recommended its use as a treatment in situations where benadryl alone was not working. I finally tried it in desperation last winter when a mild allergic reaction (full-body hives) would not go away. It worked like a charm. That started me thinking and I realized that almost all my children's mild allergic reactions occur during the winter when they are not already on medication for hay fever. It made me think that perhaps the antihistimine was suppressing some instances of mild allergic reactions. Obviously, I am not talking about allergic reactions that require an epi-pen as I wold simply use the epi-pen then. These are situations where my kid touched an allergen or perhaps ate something contaminated with trace amounts.

Anyhow, my oldest has been using Zyrtec year-round for many years by advice of one of his specialists to combat food sensitivities/vomiting due to other medical issues and I have been told that it is safe to use year-round. In connecting the dots, I realized that these two recommended uses are probably related, and that perhaps it may not be a bad idea to consider giving at least one of my two younger kids year-round antihistimine as well. Of course, I would discuss it with at least their pediatrician first.

Anyone else ever tried using Claritin or Zyrtec as a preventative or treatment for mild food allergic reactions?

No food allergies here, but my family has used Zyrtec or Allegra successfully for skin reactions (DD/DW for bug bites, me for poison ivy).

I get a severe sinus reaction 20mins after taking a Claritin.

Interesting; I guess it would make sense that Zyrtec would work for other skin reactions. We were told to switch my oldest DS specifically to Zyrtec for year-round use as he was using something else (Claritin or Allegra) for hay fever at the time.

However, unless I am remembering wrong, I believe that Claritin was on the list for treatment of mild allergic reactions that wouldn't respond to benadryl.

Our allergist has us use antihistamines during any type of environmental allergen season, but hasn't ever suggested it *directly* for food allergies. OTOH, our dd has both food and environmental allergies, and our allergy drs believe in the concept of an immune "bucket" - basically your body can handle dealing with allergens up to a certain point, but when the bucket is "full" it's going to overflow and you'll see heightened and increased numbers of reactions - hence it's important to keep the bucket at "low level" - i.e., deal with what you *can* deal with, such as taking a daily antihistamine to keep the environmental allergens down, and in turn, that helps keep allergic reactions down overall.

To be honest, this jmo, but if you're a parent who's feeling that they need to give your child an antihistamine daily for any type of allergic reaction / hives / etc / whatever the source - I'd think that's a sign that you'd benefit from taking your child in to see an allergist. Especially since you have the note about sensitivities etc. What you're seeing during the winter might be something as simple as dust mite reactions, or it might be food, or it could really be anything. My dd with multiple food and environmental allergies is also allergic to changes in temperature when she comes in from the cold - and I would have had absolutely no idea that this has the possibility of being an anaphylactic type of allergy if she hadn't been under the care of a dr experienced in dealing with allergies.

Quantum, I realize your ds is already under the care of medical specialists for other issues, but it sounds like a trip to an allergist might be enlightening.

And yes, we use oral antihistamines to treat mild allergic reactions such as hives - for reactions due to environmental allergens and due to food allergens.

I hope that made sense - it was written in a hurry!

Best wishes,

polarbear

Polarbear, your post makes sense. Mine might have been kind of confusing since I have three different kids. My older DS, whom I am least worried about in terms of traditional food allergies, has actually been under the care of an allergist but the vomiting & sensitivity to certain foods (for lack of a better phrase) that were being addressed had other medical causes and the prescribing specialist was higher up on the totem pole of his medical team, if that makes sense.

In our past experience, the allergist hasn't been much help except to determine a list of "likely" allergies. We get the epi-pen script from the pediatrician. It is my younger DS who seem to be having sporadic minor allergic reactions. You are correct that the allergy can be to other things even though each time we can point to a specific likely source with some level of confidence. The problem is that even when the allergist weighs in, he usually can't be sure of the allergy source either. Of course, it is always safest to confer with the allergist and we might do that as well. I am just really sick of doctors and there are so many that I can't avoid so I try to limit them when I can.

Anyone ever tried year-round Claritin or Zyrtec as a preventative to mild (level 1 or 2) food allergic reaction?

Our allergists (yes, multiple) have had DD taking a year-round antihistamine since she was quite small. We do this to damp down her sensitivity somewhat so that every trip outside the house isn't a 50-50 proposition for benadryl and watch-and-wait.

We also began treating aggressively with antihistamines to prevent/slow the progression of the allergic march with her. It seems to have been moderately successful, though we're still holding our breaths collectively to see what her asthma becomes as she goes through adolescence.

I'd ask next time you're in. Probably fine. DD has been on an adult dose (10mg Cetirizine) since she was about 8yo. No advice with that statement obviously.

BUT-- and here's where I don the scolding mom hat for a moment, okay, so bear with me-- if you're thinking of this as an add-on therapeutic agent for an acute allergic reaction in-progress-- DON'T.

If benadryl isn't enough, that's a sign that there's more going on than you CAN see. That's dangerous to try to treat with antihistamines alone. Take a look at this, if you've not seen it before:

http://www.the-clarkes.org/stuff/ana.html

It's a plain language description of a variety of presentations of allergic reactions-- just know that anything systemic is potentially dangerous, and a lot of stuff is pretty subtle/hidden until it is VERY severe. If you wait too long, epinephrine isn't very effective.

There.

I'm sure that you know that. But I have to say it anyway because it's who I am. Mom worries.

My son who is anaphylactic to peanuts and tree nuts also has seasonal/year round allergies to pollen and mold. As a result, he takes an antihistamine year round. Until the middle of first grade he was taking Claritin. After I told our allergist that he was getting random hives on his face (usually only one or two) EVERY DAY that he was at school, even while taking Claritin, she suggested changing to Zyrtec or Allegra. We changed to Allegra, as my other son was already taking it, and the hives went away. One time we ran out, and by the end of the day he had another solitary hive on his face. I don't know for sure that the hives were related to his food allergy, but they were because of something at school. They started after he started going to school and he didn't have them during the summer or during school breaks - his school wasn't peanut or nut free, so it seemed very possible that he was having some sort of contact reaction.


He did have an anaphylactic reaction earlier this year, and hives/swelling were not one of his first symptoms, as with his previous reaction. He did get hives, but not until AFTER he was experiencing other more serious symptoms. So I don't know if being on a daily antihistamine affected the anaphylactic reaction in any way - they say all reactions are different.

I will say that when he started complaining of itchy eyes at the beginning of the reaction, I DID NOT give him benadryl, as I was concerned that he was starting to have a reaction and didn't want to mask any symptoms. He wasn't given Benadryl until AFTER he had the epi.

I don't recall now since it's been more than 7 years and it was one of his more minor issues, but the specialist had explained that there is something in the way Zyrtec (Cetirizine) works, which makes it the best choice for my oldest DS for his combined issues.

Fortunately, at least asthma isn't an issue for any of my kids. Their cousins aren't as fortunate in that regard and it can be pretty scary to witness.

We normally don't stop the antihistamine for hay fever until November so that should give me a chance to talk to their pediatrician at least.

I know what you mean. I wish I remember the medical source without looking it up, but the Zyrtec was recommended as an add-on therapeutic agent for an allergic reaction that wasn't responding properly to benadryl. It was either that or go to the emergency room on a week-end evening (which can also be traumatic if not dangerous!).

Actually, I am most leery of neurological and respiratory symptoms but there were none. There also weren't the projectile vomiting, lethargy, diarrhea, and body temperature changes that sometimes accompanied his more severe allergic reactions. Of course, I could have been completely wrong but it didn't feel life-threatening that time. The problem with hives is also that it isn't uncommon for recurrence from the same exposure over a period of days and sometimes even weeks later.

I understand where you are coming from and mostly it is better to be safe than sorry. There are certainly enough tragic incidences. Heck, sometimes the chilling stories are enough to make a parent consider injecting with epinephrine as a preventative! I also don't want to over-react and freak out the kids as they are learning how to monitor their own allergic reactions. I struggle from time to time with balancing how much bubble-wrap to use. I tend to overuse with my oldest and under-use with the other two.

Food dye sensitivity is not my friend. Blue #1 in it rendered it pretty much useless for my needs. Imagine the discussion with your doctor when you say, "Hey, I think I'm allergic to this antihistamine..." and get blown off. I also have a good number of allergies in my 30s I didn't have when I was young, so I totally agree with a poster above who mentioned that overflowing bucket.

One other thing I will note here is that Benadryl isn't good for glaucoma (or those with higher than normal eye pressures). I never had high eye pressures until I got all of my allergies and had to take medicine for them.

Always give the allergist a full-health run-down and mention these things I have also been told that certain antihistamines can work on stomach acid (though I think that's more of an off label use).

Thanks for sharing. Actually, my third child (DD) gets random (usually only one or two) hives on her face as well. However, it only happens a few times a year and most of the times we can't tie it to any specific food. Since it is only one or two and goes away the same day, we just keep an eye on it and generally don't give her benadryl for that. Her obvious allergic reactions, which we can generally tied to a specific source, usually include other symptoms as well as more severe hives with swelling.

There are so many possible combinations of symptoms that it can make it confusing to track. I know that I would not have known to connect itchy eyes with a food allergy, but that's because in my DS' case, he usually has other issues causing itchy eyes.

I have also heard that developing new allergies as an adult is not uncommon. Thankfully, those aren't usually as severe. That's an interesting tidbit about stomach acid - maybe I should look into that particular use.

The use of H1 receptor blockers including Zyrtec and Clartyne are first line treatments for allergies including food allergies. They block the histamine mediated effects including the rash, itch and some respiratory effects.

Stomach acid release is mediated by histamine binding to H2 receptors. H2 antagonists (blockers) include ranitidine and famotidine. There is some evidence that H2 antagonists may help with the late, second stage, or relapse effects in severe allergy but they are not recommended as main line treatment for allergy. Similarly corticosteroids are used in anaphylaxis but as a second line measure to prevent late responses.

The problem with the regular use of H1 blockers is the patient may miss the first signs that they have ingested an allergen and consume more of the product so have a higher allergen load on board when symptoms appear. It's just something to be aware of.

Allergies develop at all stages of life. Unfortunately patients can develop allergies to medications which have previously been safely used and respond with anaphylaxis on later doses. Allergy can be severe at any time not just in childhood.

Food allergies can also develop later in life due to cross reactivity in similar shaped molecules in other products. Latex allergy is linked to food allergies due to cross reactivity with food triggers including kiwi fruit, banana, chest nuts and avocado.

First line treatment for all allergy is antihistamines then epinephrine given as soon as severe allergy manifests. Other treatment includes IV fluids and occasionally glucagon if patients are on beta blockers as they block epinephrines effects.

Once histamine is activated the response is generalized so that is why food allergies can also manifest as runny eyes or nose, itchy eyes or nose, rash or hives, itchy skin etc. gastrointestinal symptoms include nausea, vomiting, diarrhoea or abdominal cramps, burning in the chest. Respiratory symptoms of wheeze, shortness of breath, itchy throat etc can occur with any allergy, a bronchodilator such as salbutamol can be used. There are also neurological symptoms and so on.

H1 blockers will act at all sites o histamine action but have limited effectiveness against severe cardio respiratory effects including bronchoconstriction, blood vessel dilation which causes hypotension (low blood pressure) and poor pump function of the heart. These are treated by epinephrine and fluids. Fluids alone are ineffective because blood vessels get leaky and that causes edema or swelling in all kinds of tissues including the airway. Therefore epinephrine first to decrease the permeability of blood vessels which contributes to the swelling.

By the way Benadryl contains the H1 antihistamine diphenhydramine. If that isn't working, adding another proprietary H1 blocker, such as Clartyne or Zyrtec, doesn't work,as those receptors are already being acted on by the diphenhydramine. Zyrtec etc are just longer acting formulations, molecules that do the same job as Benadryl but stick around longer and have the advantage that they cause less drowsiness as they are not as neurologically active.

As Polarbear said, always see your doctor if you have concerns or recurrent symptoms. Allergies are a very tricky beast as Howler karma will remind you. And they can change for better or for worse over time.

Yeah-- older first-gen stuff is both H1/H2 blocking, but shorter acting, and as ndw notes above, the second generation meds are more selective for H1 receptors, which tend to exclude the CNS H2 sites (thus making them "non-drowsy" or at least better for most people). They work FAR better (for most people) on the irritating peripheral symptoms like skin, eyes, nasal congestion. They're also a lot more idiosyncratic in terms of individual action, however. (So if loratidine does nothing, the advice is often for patients to try cetirizine, or fexofenadine, for example...)

One thing which is useful to recall when using first-gen versus second-gen antihistamines is that they do various things selectively, and one may sometimes make use of those properties.

Diphenhydramine is useful for GI reactivity in particular-- to the point that it often works as a mild anti-emetic.

Ranitidine is also a histamine blocker, though it's got nowhere near the efficacy of something that hits systemic H1 and H2 receptors like diphenhydramine.

Just recall that those older generation antihistamines that indiscriminately hit both receptor types can cause drowsiness that masks neurological/cardiovascular effects of a systemic reaction.

All this pharmacology-- better living through chemistry at my house, anyway!

Diphenhydramine also acts as an anticholinergic which slows the gut motility and contributes to antiemesis and drowsiness.

Drowsiness, as HowlerKarma, is also a symptom of severe allergy, anaphylaxis, and masking that is very bad. In mild nausea being able to sleep is nice. The drowsiness component is the reason diphenhydramine was used as a sedative adjunct in some Anaesthesia but it has hangover and other side effects that newer agents don't, so I have never seen that done.

Okay I have a question...someone said taking Benadryl and then taking Zyrtec doesn't really work.

My son takes daily Zyrtec for pollen, seasonal allergies (except it is fl and we don't have seasons it is generally year round)....we go visit grandma and she has a cat...he adds a Benadryl to the Zyrtec for a few days and can function without clawing out his eyes and sneezing constantly.

So b then z does no good but z then b can add to the therapy?

Not really true-- the order doesn't matter all that much, except that the off-rate for diphenhydramine on the H1 and H2 receptors that it hits is much faster-- of course, even with zyrtec, it's not as slowly metabolized as it is in adults, so this is why dosing is often twice daily in children.

Mostly the reason for cetirizine as a primary therapeutic agent (with diphenhydramine added as needed) is that the former doesn't lead to CNS side-effects because of receptor selectivity, and it lasts longer.

A relatively minor reason from a pharmacokinetic standpoint is that diphenhydramine has a shorter effective window and blocks sites that would otherwise be occupied by longer-acting cetirizine, but even so, this isn't really a compelling reason. Taking zyrtec and benadryl simultaneously, for example, just means that circulating zyrtec would (hypothetically) fill histamine receptor sites as the diphenhydramine vacates them. If that makes sense.

We've very definitely used zyrtec as a fast-acting add-on therapeutic-- and come to that, so has our allergist right in front of us. Mostly, we use benadryl that way since we all use cetirizine as our first line agent.


But the dosing window for both is very wide. The safety profile of the first gen antihistamines like benadryl is not as good as it is for zyrtec, though, due to CNS depression.

So that probably goes into a lot more detail than anyone cares about, but my ultimate answer is "why on earth would anyone choose to use diphenhydramine as a FIRST agent when second-gen antihistamines exist?" In other words, I'd expect it to be a rather unusual set of circumstances to begin with, where one would be in a position to do benadryl THEN zyrtec. But there's no compelling pharmacological reason why it's unsafe or ineffective. Well, you might lose a touch of the zyrtec to metabolism as it circulates in the bloodstream doing nothing for a few hours until some H1 sites open up-- but it's not likely to make an appreciable difference.

All of this also ignores the fact that H2 sites are mostly left untouched by zyrtec, which is another reason why adding benadryl can seem "effective" whereas adding zyrtec may seemingly make little difference.

Does that help?

Thank you, ndw - those are nice, clear explanations. Looking over my posts, I realized that I have probably been unclear and created some confusion given that I am posting about three allergic kids with divergent medical histories and different reaction profiles.

I also want to add that reviewing medical research should be coupled by conversations with medical professionals. In certain specific situations, adding Zyrtec after Benadryl has been highly effective for my younger DS and his doctor concurs. Please check with yours. I am talking specifically about situations where epinephrine is not indicated and you can see some effects of the benadryl but it is not fully effective. For example, the hives improves substantially but not completely and returns too quickly. Doctors routinely prescribe higher dosages of benadryl than instructed on the bottle and that can help sometimes. However, adding Zyrtec provides a much more powerful boost. I have seen it in action twice. Again, please check with your own doctors.

Thanks, Howlerkarma - that's a great summary and a prudent reminder about the potential masking effects.

Cookie, you got a much better answer from Howlerkarma than I can re-invent but both b then z and z then b have been effective for my children under the different situations.

Thanks HK...

I agree we are very happy with Zyrtec and once a day (he is a very small 14 year old) is working for him at home. I had never heard that younger kids might need two doses.

..it is only when you add the cat...(and he has no food allergies)...and at that point we want fast acting. His pediatricians have been fine with that for a long time...we only visit for 3-7 days at a time mostly long weekends. So he gets three additional Benadryl doses once every two months. That doesn't feel excessive to me. And 14 year old desperately wants the cat to like him...luckily she is mean.

Signed, not a cat person at all

My mom is allergic to cats and would take Claritin two to three days in a row before visiting my aunt who was a crazy cat lady. She tried to visit mostly at a restaurant in her town and minimize her time in my aunt's house. I am surprised my mom doesn't have an epi pen for all her allergies. Some of them are quite severe.

Howlerkarma, that is a helpful explanation and clearer (more accessible) than what I had come across previously.

My initial post brought up two separate issues - using zyrtec daily as a preventative therapy and using zyrtec as an add-on therapeutic. I was confident of the efficacy of the later (in certain instances) but was wondering about the former. Although my older DS has been taking zyrtec daily for 7 years, it wasn't to prevent reactions due to his "traditional" food allergies so I wasn't sure about having my younger DS take it daily to help prevent allergic reactions.

Your latest post plus one of your previous ones set out the reasons very well and may help someone else approach their doctors with the right set of questions.

Thanks-- but let me reiterate that our strategy is probably not the correct one under all circumstances, and we see a very fine board-certified allergist, with whom we work closely.

Still, all of this stuff is a work in progress all the time. That allergy bucket/cup thing is all too real, unfortunately. So is the allergic march. A lot of clinical practice in this area (not the pharmacology, of course, but the bigger-picture stuff touched upon) is hypothetical at best, unfortunately.

There's no way that H1/H2 receptor therapies are anything like a magic bullet for preventing serious systemic responses to life-threatening allergens. HAVE to say that. I know that everyone who has participated in this thread thus far is well aware of that, but over the years, I've heard some pretty wacky ideas, and that's definitely one of them that I hear a lot.

My daughter and I both take high doses of cetirizine daily, and we've both anaphylaxed pretty floridly while doing so in spite of that "protection." It can definitely happen, and exposure to an allergen that you have life-threatening history with is just not a good idea without specific, expert medical guidance. This stuff isn't even a DIY project for someone like me; I treasure our partnership with our allergist, and we are VERY compliant patients.