You may have oral allergy syndrome (OAS), which is similar to food allergy but not as severe. It doesn't typically lead to anaphylaxis. It is caused by pollen allergy, where the food has a protein similar to one that's in the pollen you're allergic to. This is called "cross-reactivity".

Personally I have OAS with raw carrots, which is likely cross-reactive from my birch pollen allergy. Raw carrots make my throat mildly itchy, but I don't have a food allergy to carrots and I don't get anaphylaxis. Cooked carrots are totally fine, the cooking destroys the protein. This is a common feature of OAS.

Actually, while I did have OAS with carrots in the past, I have recently been undergoing immunotherapy for pollen allergies (plus cat dander and mold) and in addition to my hay fever symptoms disappearing, I no longer get the itchy throat with raw carrots.

This page has a list of common pollen allergies and the foods that they may be cross-reactive with: https://www.chop.edu/conditions-diseases/oral-allergy-syndro...

Not a week passes where I do not learn something interesting on hn! And this one may even be life altering!

Took me 30 years to find out that I have pollen allergies, and from that food allergies.

And because my body only produces very little diamin oxidase, that leads to heavy symptoms elsewhere in the body. I just recently got so far that diet and fenistil make things usually bearable, and when it gets heavy, only a little more fenistil fixes the symptoms. I don't think the symptoms are anaphylaxes, but overabundance of histamine. I had too many of them and I'm still here, never had to use the epi pen.

But from all the specialists I visited in my country, no one ever told me, that OAS exists, or oral therapy against them.

I can't say how thankful I am for the new ideas from your post and the child posts!

Glad to help! Just wanted to note that my immunotherapy for pollen/cat/mold allergy is not oral, but subcutaneous. That is, allergy shots. Oral (probably sublingual) immunotherapy can be done also, but for these allergens I believe subcutaneous is more common. I am not sure of the reasons but they may be related to efficacy, safety (eosinophilic esophagitis does not occur with shots), or convenience (while shots are not exactly convenient they are only once a month vs. daily oral therapy).

If you have frequent reactions, I'd say you should really consider immunotherapy. Even if they haven't been bad enough to kill you yet, the next one can always be worse. And if you have borderline anaphylaxis, waiting to administer the epi-pen can be fatal, as it can be less effective if you wait too long. Antihistamines will not save you from anaphylaxis, as while they reduce/mask some symptoms they do not treat the specific symptoms that kill you (hypotension, and/or airway swelling leading to suffocation). Only epinephrine does that.

Thank you for taking the time to reply to a rando fellow nerd. Really appreciated!

Is this why I sometimes get little tiny pustules on my gums after eating certain foods? I have no idea which foods cause this still. Sometimes in happens with sushi

The wasabi (actually horseradish with green die) is probably irritating your mouth.

Maybe the avocado bothers you? That's a common one.

Definitely not avocado. I've been eating an avocado for breakfast every day for almost a while month now and have not gotten them.

What are egg whites linked to?

That symptom matches my reaction to egg whites but the weird thing is, it's only some forms. I can eat hardboiled eggs no problem (probably because the allergen has denatured), but not most other forms itch while baked goods are very hit or miss. The worst are meringues and macaroons.

You probably have a genuine food allergy to egg. I don't see egg in OAS lists. I see some research saying that common egg allergens are destroyed by cooking as well (though this is not true for all cooking methods or all food allergens). I would see an allergist. It's probably a good idea for you to carry an epi-pen. Even if you've only had low severity reactions so far, it's always possible that the next one will be severe, and egg is hard to avoid.

I have OAS/mild latex allergy and cantaloupe/honeydew are pretty terrible, and avocado was a bit bad too (worse when paired with acid e.g. guac)

My wife eats a lot of avocado being from south america and that part went away, and the latex allergy seems to have reduced as well.

I have cantaloupe/honeydew but no problem with avocado or latex so I don't suspect a connection here. Raw bell peppers sometimes bother me.

Allergies are often funny, at least for me. Exposed to a single allergen usually results in no reaction. But many, many small exposures to diverse allergens adds up and can trigger a disproportionate response.

I have a friend who's food-related allergies (non-anaphylactic) disappeared after removing carpet flooring in their home.

> many small exposures to diverse allergens adds up

Yeah, that's a thing. Also you may notice higher sensitivity to allergens if your immune system is fighting off a cold (perhaps even before you're aware of being sick, or even if someone in your household is sick and you don't get it because your immune system successfully fights it off). If you are doing oral immunotherapy it is sometimes recommended to reduce your dose when you are sick to avoid reactions.

Hey! I'm in the same boat with raw carrots, as well as melons like cantaloupe and watermelon. Annoying because I love them all.

Well, you might consider allergy shots for hay fever, that just might fix the OAS too!

Ah I take an over the counter pill daily and it handles my typical allergy symptoms. I may revise that opinion once I move back home where it seems to have been the worst.

It takes a long time for allergy shots to ramp up. It's likely that they work better the younger you are, and of course also the younger you are the longer you have to enjoy the benefits. So I'd start as soon as possible if you think you would ever want to. That said, allergy shots are not for everyone. It's a big commitment with real risks and it's not always a lifetime cure. If you're happy with antihistamines that's fine. Personally, Claritin and Zyrtec were not effective and I was also concerned about the potential long term effects of daily antihistamine use.

Kiwis are also linked to latex allergy. I have friend who has latex and kiwi allergies.

Yes, it is certainly possible to have a true food allergy to kiwi as well, with anaphylaxis and everything. It may even be relatively common these days in some places.

Leading to many of the NZ fetish scene jokes :)

I've got the same thing with kiwis.

I discovered it in a funny way - I was in Tokyo trying all sorts of random foods. One night after dinner, in the cab, my throat started to swell. I had a fun time getting some emergency Benadryl from a gas station late at night speaking Japanese poorly.

I had no idea what caused it.

Flash forward a few months, I was at a birthday party back in the U.S., had a slice of kiwi, and felt like I'd swallowed battery acid. Throat immediately closed up, worse than in Tokyo. Thinking back to that previous night, I realized it hadn't been some exotic food - I'd had a salad with kiwi in it.

Fun and rare allergy.

For even more fun, try being allergic to milk. I developed that allergy later in life and hoo boy has it been a humdinger.

I started getting something a bit like that with bread. My whole mouth would go numb. I've eliminated it from my diet - was a bit of a wrench, but I've got over it now, and no more numb mouth.

I also think the very fine hairs may just be very irritating, not necessarily allergic, although you should get tested if you think its true.