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7 Things You Should Know About Oral Allergy Syndrome

 

Did you know pollen might be responsible for your allergic reactions to fruit or vegetables? If your mouth or throat itches when you eat certain fruit or vegetables, you could have oral allergy syndrome (OAS). And you would have a pollen allergy to thank for that.

1. Cross-reactivity is the reason for OAS symptoms. OAS is the result of a confused immune system. The pollen of some trees and grasses are similar to the proteins of certain raw fruits, vegetables, seed or nuts.

2. Birch, alder, ragweed, mugwort, Timothy grass and orchard grass pollen cause most OAS symptoms. These pollens are similar to the proteins of certain raw fruits, vegetables, seed or nuts. If you are allergic to any of these pollens, you may have OAS symptoms.

3. You may be able to eat foods that cause OAS symptoms if you remove their skins and/or cook them. Heat affects the proteins, so you may be able to eat these foods cooked instead of raw. For example, a fresh apple may cause symptoms, but a person with OAS may be able to eat applesauce without symptoms.

4. If you’re allergic to these pollens but don’t have symptoms when eating related foods, you can still eat them. But if you have severe OAS symptoms, avoid those foods and talk to your allergist.

5. Your OAS symptoms may be worse when pollen peaks. For example, birch trees release pollen January through April, depending on where you live. Ragweed pollen season is in the summer and fall. You may notice that your symptoms are worse during the times when the pollen you are allergic to is highest.

6. OAS can be confused with food allergy. It can cause symptoms such as an itchy or tingling mouth, face, tongue or throat. You may also have some mouth and throat swelling or hives where the food touched your skin. Rarely, OAS can trigger anaphylaxis, a severe allergic reaction, so it is important to know if you have OAS or a food allergy and how to treat it.

7. If you have OAS symptoms to nuts, this could actually be signs of anaphylaxis, a serious allergic reaction. If you have any symptoms while eating nuts, see a board-certified allergist as soon as possible. Nuts are more likely to cause a serious allergic reaction which must be treated with epinephrine and immediate medical attention. And if you don’t know if you are having OAS symptoms or anaphylaxis to any foods, talk to your allergist.

Here is a list of some pollens and the foods they may cross-react with. You may not react to every food on the list.

Birch Tree Pollen Cross-Reactions

  • Almond
  • Apple
  • Apricot
  • Carrot
  • Celery
  • Cherry
  • Hazelnut
  • Kiwi
  • Parsley
  • Peach
  • Peanut
  • Pear
  • Plum
  • Soybean

Alder Tree Pollen Cross-Reactions

  • Almond
  • Apple
  • Celery
  • Cherry
  • Hazelnut
  • Peach
  • Pear
  • Parsley

Ragweed Pollen Cross-Reactions

  • Banana
  • Cantaloupe
  • Cucumber
  • Honeydew
  • Watermelon
  • White potato
  • Zucchini

Mugwort Weed Pollen Cross-Reactions

  • Aniseed
  • Bell pepper
  • Black pepper
  • Broccoli
  • Cabbage
  • Caraway
  • Cauliflower
  • Chard
  • Coriander
  • Fennel
  • Garlic
  • Onion
  • Parsley

Timothy and Orchard Grass Pollen Cross-Reactions

  • Orange
  • Peach
  • Tomato
  • Watermelon
  • White Potato



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@BenR posted:

I recently had issues cutting potatoes where I got itchy hands and a rash and hives  up my hands , neck and chest . Doctor thinks that it’s the oral allergy syndrome strikes again with the grass and ragweed as main culprit .  You remember the incident with the tomatoes ? She said there in the same family so it would make Sense .  Also I’m seeing a Gastro specialist for some tests and he said when your digestive system is inflamed the more likely you can have these bizarre allergy attacks .

Hey Ben - that's interesting that raw potatoes are causing a contact reaction on the your hands. And yes, potatoes and tomatoes are both in the nightshade family. Good luck with the gastro appointment and tests. I hope you will check in on the forums to let us know how that goes. 

Tommy, my 8 year old, has both food allergies and OAS to a lot if things that cross-react with his pollen allergies. The difference with his OAS is that some times of year he can eat the foods just fine (like cucumber which cross-reacts with his ragweed allergy) but as soon as ragweed season comes it gets him itchy (especially under his arms). Then only if his ragweed allergy is bothering him or flared he will react to sunflower seed which stinks because he loves sunbutter and jelly sandwiches (we are both very allergic to nuts and avoid them always so we use sunbutter as a substitute). He also cannot eat cantaloupe or honeydew and his doctor said it might be a full blown allergy after a past reaction but Tommy has refused anymore skin prick tests and I do not want to force him to, so we just avoid it as a full-blown. 

I am so allergic to apples, grapes, peaches, pears, and plums that I cannot eat them raw, juiced, cooked, or fermented. I haven't been formally skin pricked for those but I know from severity of reactions because they quickly progressed from itchy and flush, to vomiting, to hives and breathing difficulties so I avoid them strictly along with ones I did get tested positive for formally, like all nuts. I developed both at around the same time and it was immediately after a major GI surgery, so I definitely think when the body us under health stress that allergies are going to pop up more and be worse. And once some allergies are flared up, cross-reactivity seems worse too. My son's eczema also flares during those tines for him. 

@KathyP I recently had issues cutting potatoes where I got itchy hands and a rash and hives  up my hands , neck and chest . Doctor thinks that it’s the oral allergy syndrome strikes again with the grass and ragweed as main culprit .  You remember the incident with the tomatoes ? She said there in the same family so it would make Sense .  Also I’m seeing a Gastro specialist for some tests and he said when your digestive system is inflamed the more likely you can have these bizarre allergy attacks .

I’ve had oas to apples, pears, all stone fruit, almonds as well as hazelnuts since my childhood. And it’s gotten progressively worse. I used to be able to eat these foods cooked or baked, now this is not even possible anymore. I got a blood test a few years ago and only hazelnut came back positive. But I know when eating raw apple my throat closes up. I have to carry an epi pen with me now. Any chance it could get better? I still get dreams of eating apples. 

New to this blog and I have to say I am relieved to know that all the issues I have been having with food is real. I have always had issues with eating bananas. The past few months I have been having oral reactions to foods. I think it is bell peppers. I am thankful to have found this blog. 

Thanks.

It’s better now . I didn’t realize watermelon crosses with grass . I know it does with latex and also ragweed. Also the list make sense since I can’t meet broccoli and cauliflower.

Thank you for sharing this information. My allergist mentioned OAS but I didn’t quite understand. This article is great. Now I understand why peach salsa makes my mouth feel odd! 

 The last column isn’t being over lapped by all the boxes . This happens to me  when I have mango , pineapple and tomatoes it’s only during certain seasons. I’m allergic to grass , willow tree, ragweed . I’m also allergic to latex which can have cross reactions as well . Such as with the skin of some Mellon’s  and avocado .

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