The Scoop About Oral Allergy Syndrome


I’m allergic to stuff. If you follow the Lauren’s Hope Blog at all, you already know this, as I seem to talk about it ad nauseam. But allergies are a big deal! And as I mentioned recently, I’ve just been diagnosed with Oral Allergy Syndrome.

So, What Is Oral Allergy Syndrome?

Oral Allergy Syndrome, sometimes called OAS for short, is a really bizarre twist on food allergies, if you ask me. I think of it as my immune system getting kind of lazy. Here’s the deal. Usually, allergies look like this in my mind:

Person With Allergy + Allergen = Reaction

So, for me, I’m highly allergic to ragweed. When I was scratch-tested by the allergist, my entire upper arm swelled up and itched for days. When exposed to it in the real world, I am beyond miserable. So in my highly sophisticated equation:

Me + Ragweed = Miserable Reaction

This, at its most basic level, is what environmental allergies are. Our immune systems recognize something as a “foreign invader” and attack it. However, with Oral Allergy Syndrome, in my view, the immune system is both over-reactive and a total slacker. It looks something like this:


Person With Allergy + Food That Sort of Resembles An Allergen = Reaction

See what I mean? Lazy immune system doesn’t check to make sure it’s actually an allergen, it’s just essentially saying, “Meh. Guilt by association. You remind me of that allergen, so I’m going to completely freak out for no reason.” And it does. That means that if I’m tested for a tomato allergy, for example, it will always come back negative, but then sometimes tomatoes will cause a reaction anyway. Which takes us back to my highly technical equation:

Me + Tomatoes (which apparently have proteins that are similar to ragweed, according to my immune system) = Reaction, But Only Sometimes

How weird is that? Pretty weird if you ask me. I’m still wrapping my head around it. But it does explain why sometimes I seem sensitive to orange juice and carrots, but sometimes I’m not. These are cross-reactions with pollen and grass allergies. For me, as I have been more closely tracking my reactions, what I see is that if something is in bloom and I’m frequently being exposed to it, such as a flower or grass to which I’m allergic, then I will see more food reactions (skin, throat, or mouth itching; hives; etc.), likely because my immune system is already in overdrive trying to handle all the environmental allergies.

For a more technical explanation that still uses layman’s terms, I found this Allergic Living article very helpful, plus WebMD covers it well here. And please remember, we’re not doctors here at Lauren’s Hope. This is my personal experience, and yours may be quite different. If you think you may have Oral Allergy Syndrome, please consult your Primary Care Physician or Allergist/Immunologist.

Do you live with Oral Allergy Syndrome? We want to hear from you!


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