Can one become tolerant of an allergy?

What happens if you have a mild allergy to a substance and you eat/breathe/touch/whatever it frequently? Is it possible to become less allergic or does it hurt your health or what?

It varies. Sometimes low dose exposure to the allergen results in the production of IgG antibodies instead of IgE antibodies (the ones which cause allergic reactions). This can result in the body stopping production of IgE. This is the mechanism behind “allergy shots”.

Doesn’t work for all people or all allergens, though. And results may not last a lifetime.

As Qadgop said, it depends. I know for some drug allergies, they will give the medication over a long period of time, and desensitize the patient to the drug. When they do this, the patient will no longer have a reaction to that drug. However, once they discontinue the medication, the allergy will return.

This is most normally done in long term treatment, when the drug is the best choice and there isn’t any other good options. Most commonly happens with sulfa allergies and Bactrim for AIDs prophylactic.

As a child, I was pretty much always pink from Caladryl for poison ivy. It is growing all over my yard and I haven’t succumbed. I don’t think I’ve had a reaction in more than 15 years (if the date of my bottle of caladryl is a sign)

Just to add that I don’t believe that any food allergies can be lessened by exposure as an adult.

However, some researchers are having successes in reducing reactions by young children by starting them on extremely low does (1/1000 of the reaction value) and then very gradually increasing them over time. Peanuts, eggs, and dairy have all been successfully introduced this way.

Here’s one story about it.

I don’t know of any research that says this has worked on older patients, though.

I remember my dad doing ragweed allergy shots…dont think they worked as he was allergic to ragweed until he died…

I have a lowgrade allergy to somethings that pop out pollen around here, forsythia for one, and some form of pine tree [whatever sperms yellow pollen all over my cars] and probably some form of grass. They give me the itchy eyes and sniffles but I tend to pretty much ignore and suffer through as it is pretty low key and i cant see adding yet another fuckign pill to the handfull I hork down every day. I wouldnt mind if they could cure it, but eternal pallative measures suck. I take enough fucking pills every day.

Sometimes repeated exposure to an allergen can make the allergic response worse. You might have a mild reaction at first, then after multiple exposures develop a more serious reaction. One must be very careful with allergens.

You may also become hyperallergic to the substance.

I have an allergy to some shelled sea foods. Shrimp, scallops, and crab. I like both shrimp and crab. With carb I think I ended up hyperallergic. Srimp had a smaller reaction so I would just take one bite of shrimp when it was at the table. With the small bite I had a small reaction (crab, small bite big reaction). After a number of times I got no reaction with one bite of shrimp. Then I started eating one shrimp at a time, small reaction. I kept it up until I now can eat a shrimp dinner with out any problems.

so the answer to the OP’s question is it depends.

Interesting. I always thought that would make sense, but I never heard of anyone doing it. I don’t have any allergies myself that I know of so I can’t really experiment on myself.

FWIW a journal abstract regarding adult food allergies:

And then there are also cases of allergies appearing or going away for no discernible reason at all. A family friend was extremely allergic to both wheat and dairy (actual allergy, not just lactose intolerant) about 20 years ago, but now has no problem with either.

My experience as an adult with food allergies is that every time I inquire about the issue to an allergist the response is “no one is doing research on adults”. It used to be that was followed up with “… because food allergies in adults are so rare” but I’ve noticed in the last 15-20 years they’ve stopped saying that. I guess it’s not rare anymore!

It actually makes some sense to work this out for the kids, first, as kids are far less responsible than adults at avoiding allergens and also are less free to refuse items. (I and my highly allergic niece both experienced episodes when we were young children where adults tried to either force-feed us stuff we were allergic to, or trick us into eating it, often to “prove” it was all in our heads and were were just spoiled, not allergic. This is far less likely to happen to an adult). I expect, though, that just as desensitizing shots seem to work equally well in adults as in children that food desensitization would likewise work for both groups. I will not try it on my own, however, until someone actually does the research to confirm this hypothesis.

When I was a little kid, my parents had 2 cats, and I don’t recall ever being allergic. They gave the cats to a friend, then I noticed that whenever I would go to a friend’s house, I would get sniffly and snuffly. After a few years I had a full-blown cat allergy. Going to a friends’ house with cats became a nightmare.

About two weeks ago I found a little cat running around in the streets. I took it home and bought it a litterbox and some tuna fish. After making sure that there was nobody looking for it with ads or anything, I decided to keep it. It’s been in my apartment for the past two weeks. For the first few days, I was very allergic, so I took Zyrtec. Without the Zyrtec, I would sniffle and sneeze. But after about a week I found that I don’t really need it anymore. Now I pet and play with the little cat and have no trouble at all.

I used to have food allergies. They manifested as rhinitis rather than anaphylaxis, fortunately. Two things sorted me out: desensitisation and diet restriction which got rid of most of it and putting on a lot of weight which knocked it on the head. At 6’4" I used to weigh about 11 stone until I was about 29. Then I put on weight rapidly and my health problems dwindled markedly. Two years ago, I weighed a bit over 17 stone. Now I’m just under 16 stone, and looking to get to 15. I wouldn’t mind staying at 16 if the flab were converted to muscle. :smiley:

I’m still careful about what I eat.

Yep. My allergist’s advice to me upon hearing that I have a very mild, entirely stress-related allergy to peanuts was: never be without benadryl. Apparently very mild food allergies can become epitaphs without much in the way of a warning.

Another anecdotal response - as an adult I developed a probable/highly likely food allergy to chicory (aka chicory root fiber or inulin), which is used in a wide variety of high-fiber foods these days. I tested negative on my allergists’ attempt at a skin test, but they basically said that these tests can have a high false negative rate, and that it was too dangerous to try an ‘oral challenge’ especially considering my symptoms had increased in severity each time. Same instructions - don’t eat the stuff, not even a little bit, and keep Benadryl with you always.

I think my environmental allergies, fairly strong as a child, have waned with time.

My wife is/was the same way.

She had been violently allergic to cats her whole life; visits to cat-owning friend’s houses were an sinus nightmare. Last year our little boy fell in love with a cute little Siamese kitten at a PetSmart store, and we decided to go ahead and adopt him.

For the first week or three, the wife was a sniffling, snuffling, sneezing, red-eyed wreck who was popping Zyrtec and Benedryl like Tic-Tacs. After a while, though, she stopped having any symptoms at all.

Anecdotally, I get pretty bad hay fever every summer, but only for about 2 weeks max. (Hay fever is an analogy to pollen -you know sneezing, terribly itchy eyes and nose) I always think I should make an appointment with the doctor to get some perscription antihistamines, but by the time I get round to it it’s always on the way out and I’m fine for the rest of the summer.

Don’t know if this is related to some sort of tolerance mechanism. It could be more a case of the peak pollen season being actually quite short - not sure.

Similar thing happened to me.

While my cat allergy was not truly awful it was definitely noticeable and not fun.

GF got a cat and in a few weeks I became pretty tolerant of the little beasties. I still get a welt and itch like mad if I get scratched but the sinus issues and itchy eyes went away completely.