Fruit Allergies and Oral Allergy Syndrome

Fruit Allergies and Oral Allergy Syndrome

The top eight food allergens (milk, eggs, peanuts, tree nuts, fish, shellfish, wheat and soy) account for about 90 percent of food-allergic reactions. Other foods, ranging from meat to fruit to spices, make up the remaining food allergens.

One group of food allergies that is becoming more common are fruit allergies. But while there are people who are actually allergic to fruit, in most of the cases where people think they are allergic to fruit they are actually experiencing what is known as oral allergy syndrome.

Oral allergy syndrome (OAS) is a reaction that sometimes occurs when a person who has hay fever, or is allergic to pollen, eats fruits or vegetables (most often fresh) that contain prolifins. Prolifins are proteins found in grass, weeds and pollen; they are also found on fruits and vegetables. This triggers a cross-reaction, usually an itchy feeling in the mouth or throat, tingling in the lips or tongue, and sometimes swelling. Vomiting, diarrhea and even anaphylaxis may also occur. The reaction usually happens within minutes, but it can sometimes take up to two hours for symptoms to occur.


OAS can happen at any time of the year, but it is at its peak during pollen season. A reaction may occur to only one specific fruit or vegetable, or several fruits and vegetables may trigger reactions. Also, not everyone who suffers from pollen allergies will experience OAS.

Below is a list of pollen allergens and fruits, vegetables, herbs and nuts that may cross react with one other.

  • Alder pollen: almonds, apples, celery, cherries, hazelnuts, peaches, pears, strawberries, raspberries, parsley
  • Birch pollen: almonds, apples, apricots, avocados, bananas, carrots, celery, cherries, fig, hazelnuts, kiwi, nectarines, peaches, pears, peppers, plums, potatoes, prunes, soy, strawberries, walnuts, wheat, chicory, coriander, fennel, parsley, parsnips
  • Grass pollen: figs, melons, tomatoes, oranges, celery, peaches
  • Mugwort pollen: carrots, peppers, sunflower, coriander, fennel, parsley
  • Ragweed pollen: bananas, cucumber, green peppers, sunflower seeds and oil, melon, watermelon, zucchini, artichoke, paprika


The following may cross react to ANY of the above pollens: berries including but not limited to strawberries, blueberries and raspberries; citrus fruits such oranges and lemon, grapes, mango, figs, peanuts, pineapple, pomegranates and watermelon.

Age and Other Factors

Adults are more likely to experience OAS, however there have been children as young as three who were diagnosed with hay fever and then went on to have reactions to fruit.

Also, because the protein is richer in the skin of the fruits and vegetables than in the flesh, reactions don’t occur as frequently when these foods have been peeled. Furthermore, people who suffer from OAS usually only react to raw fruits. Since heat destroys the proteins that cause the allergic reactions, people who suffer from OAS may be able to eat cooked fruits and vegetables that usually cause them to react while they are in a raw state.

Individuals who suffer from pollen allergies, hay fever, asthma and atopic diseases such as eczema are the ones usually affected by OAS. Again, this does not necessarily mean everyone who experiences these allergies will also experience OAS—they are just at risk for it. OAS is diagnosed if a pollen allergy is already present and the individual goes on to have allergic symptoms or a reaction to raw fruit or vegetables.

If any allergy is suspected, you should consult your physician and/or an allergist. Allergy testing may be necessary to determine what exactly you are allergic to.

We would love to hear from you! Have you or anyone you know experienced OAS? Let us know. We would also love to connect with you on social media. We are on Instagram as @mykidsfoodallergies, as well as Facebook, Twitter and Pinterest.

One thought on “Fruit Allergies and Oral Allergy Syndrome

  1. I have anaphylactic reactions to lemon, lemon grass, and limes. As a child, If i sat or laid in the grass, I would develop hives and cuts all over my body. I always had severe pollen allergies, for years causing migraines every day. I never likes lemons or limes as a kid, and in all honesty maybe had them once or twice. They just weren’t something we had in the home. When I was 14, I drank lemonade for the second time (first being as a little kid and it made me have a slight reaction then, but we didn’t know that was the cause, and I absolutely hated the lemonade. I said it tingled and parents assumed I meant sour. Reaction was not severe) and had a complete anaphylactic reaction. Swelling, hives, couldn’t breathe. I was able to avoid it after, but lemon and lime has become far more popular, and is just about everywhere and in everything. Especially as more natural alternatives esceltate in popularity. My worst reaction was to lemongrass, something I had never been in contact with before. My dad had knee surgery and pain, so his doctor recommended lemongrass to rub on the knee. I lived upstairs, it was applied downstairs with doors shut inbetween. I was in my bathroom and began to swell until I couldn’t see, which was very onset. I was 19 at this point and had not had a terrible reaction since first discovering my allergy. Everything hurt and I couldn’t breathe well. I walked out and thank goodness my mom was coming upstairs to grab something, because I wouldn’t have been able to get down the stairs or yell. After the epinephrine it still took days to feel ok again. This relation with the prolifins makes sense to me, and I’m curious how it all works. I could be allergic to other citrus, but I’ve avoided finding out. Limes was not fun finding out, but I should have suspected. Very interesting read!

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.