What is Oral Allergy Syndrome?

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Many people have a food intolerance. This term refers to heartburn, cramps, belly pain, or diarrhea that can occur after they eat certain foods. However, if you feel things such as an itchy mouth after taking a bite from an apple, you might have symptoms of Oral Allergy Syndrome, also known as pollen-food syndrome.

In this segment, is Dr. Kenneth Johns joins the show to discuss oral allergy syndrome and how by identifying the triggers, you can prevent further problems, and how careful management of diet can ensure that people with the syndrome can lead otherwise normal lives.
What is Oral Allergy Syndrome?
Featured Speaker:
Kenneth Johns
Dr. Kenneth Johns specializes in allergy and immunology and practices at Allina Health clinics in Cambridge, Coon Rapids and Maple Grove. His professional interests include child and adult asthma, seasonal allergies, hives and skin rashes.

Learn more about Kenneth Johns, MD
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Melanie Cole (Host): Have you ever noticed an itchy or tingly sensation in your mouth after biting into certain fruits or vegetables? People who are allergic to pollen are accustomed to runny eyes and sniffles this time of year, but seasonal allergy sufferers may have it worse. They can actually develop allergic reactions to common fruits and vegetables. My guest today is Dr. Kenneth Johns. He specializes in allergy and immunology at Allina Health Clinics in Cambridge, Coon Rapids, and Maple Grove. Welcome to the show, Dr. Johns. So, what is oral allergy syndrome? What does that mean when people get that itchy sensation in their mouth after biting into certain fruits and vegetables?

Dr. Kenneth Johns (Guest): Well, it's the extremely common food intolerance; it’s not really a food allergy. So, by definition, it's itching, tingling, very unpleasant sensation in the mouth and lips and oral cavity immediately after you eat this increasingly growing list of fruits and vegetables, and sometimes even tree nuts. So, it isn't a true allergy. By definition, the symptoms are localized to where the food touches your body -- mostly in the mouth -- and does not progress to things like anaphylaxis, where you lose your blood pressure or your airway or have a severe reaction.

Melanie: So, is it considered more of a nuisance or is this something that you want to do something about?

Dr. Johns: Well, you know, I tell patients that it's more disruptive than it is dangerous. It -- I would say half of my patients choose to keep eating those fruits and vegetables and half of them choose to avoid them, and I’m ok with that either way. There's certainly strategies to keep eating the fruits and vegetables but not have the symptoms. So, for example, we tell people if you cook that apple or blanch that apple or freeze that apple, you're a lot less likely to have those symptoms. So, the protein that we think is responsible for the symptoms is apparently very sensitive to heat. So, you can eat those fruits and vegetables and avoid symptoms by cooking them or even freezing them.

Melanie: So, Dr. Johns, when little kids eat things like tomatoes, and we've always just thought that this was the citrus or the acid when their lips get red around the edges after eating cherry tomatoes or something like -- is that the same thing? Or is that just a reaction of their sensitive skin to that acid in the tomato?

Dr. Johns: Well, that's exactly right. It's really not an allergic reaction. It's really not oral allergy syndrome. It's just very acidic food contacting that very delicate skin. As kids get older and they learn to not smear the food all over their face, they tend to have less of those symptoms, but toddlers, especially can have a lot of that red, itchy mouth. We really don't have a good name for that one, but it is frequently seen with cherry tomatoes and citrus and other acidic foods.

Melanie: Well, I wanted to bring it up because I wanted to make sure that people don't confuse this and say, "Oh my gosh is this now oral allergy syndrome?" So, they are definitely two different things then --

Dr. Johns: -- yeah --

Melanie: -- if people do cook or freeze some of these things, is it something that they just never have to really deal with again? Or should they come to see an allergist about it?

Dr. Johns: Well, I think the concern for a lot of people is whether those symptoms actually represent a mild true allergic reaction, so for example, when someone gets an intensely itchy mouth, when they eat kiwi fruit, there's a concern that -- boy, maybe that's the first sign of an allergic reaction. So, it can be sometimes hard to tell them apart, and I think that's where it’s a good idea to discuss it with your physician. Tree nuts -- we see true allergic reactions to tree nuts, and we also see oral allergy syndrome with tree nuts, and it can be hard to tell them apart. A lot of that is again, having a discussion, and trying to tell those apart, again, can be a challenge. We really don't have the good tests for food allergy. They are very inaccurate and have a very high false positive rate, and we certainly don't have tests for food intolerances.

Melanie: So, in the event that this happens to somebody, and they notice it, how long does it take to wear off and does rinsing their mouth water or warm water or brushing their teeth, or any of these things -- is there anything they can do to get that sensation to go away? Should they try antihistamines?

Dr. Johns: When people get those full-blown oral allergy symptoms, and again, I am not minimizing them. They can be very uncomfortable. I haven't thought a whole lot that helps. We’ve tried pre-medicating with antihistamines and other types of things, which really don't block it, which I guess is another way of saying is it really an allergic reaction? I can't block it with allergy medicine. After the fact, once that mouth is itchy and tingling and burning, I've found full-fat warm liquids to be the most effective thing to help with the symptoms. So, if you have a latte after you eat the fresh apples, a lot of times that’ll help minimize the symptoms.

Melanie: Well, and in certain cultures – if food is very spicy and burning the inside of their mouth, they drink milk and --

Dr. Johns: -- I think --

Melanie: -- and is that sort of the same kind of, you know?

Dr. Johns: I think it's probably the same mechanism.

Melanie: Wow.

Dr. Johns: I think that’s probably pretty similar.

Melanie: Does it go away? Is it something that kind of sticks with you for life?

Dr. Johns: Like a lot of food intolerances, it does sort of come and go. It isn’t unusual for the food-related symptoms to occur later, and sometimes you see patients where the first thing that they notice is the oral allergy symptoms and other things develop later. So, there's always been an association of oral allergy syndrome with pollen allergy, and unlike the pollen allergy, the food-related symptoms can sort of come and go. There's a tendency for sometimes to add food intolerances so they’ll tell you, “I've always had problems with apples, and now I’m having problems with fresh cherries,” but again, sometimes they just go away.

Melanie: So, do you see that people with oral allergy syndrome may find their symptoms worsen during pollen season, and would it help to be washing your foods more? Is there anything to that?

Dr. Johns: No, it isn't something on the surface of the fruit. If you were to blanch that fruit, you know, where you dunk it in boiling water and then in ice water, that might break down that protein that we think is responsible, but it isn't something that's on the surface that could be washed off.

Melanie: So, people that are seasonal allergy sufferers that maybe also have oral allergy syndrome are kind of getting hit from both ends, and what to you tell them about identifying the triggers of both the seasonal allergies and oral allergy syndrome and kind of, you know, being able to modify some of the results of these allergies at certain times of the year?

Dr. Johns: Well, again, you can’t do tests for pollen allergies that can predict whether you might react or not. We don't have tests for the oral allergy syndrome. We certainly don't have anything that's been shown to be an accurate test for oral allergy syndrome. It's really trial and error. There is some sort of groupings. For example, people with tree pollen allergies, so they have spring seasonal allergies, they tend to have problems with the stone fruits and the apples. People that have a ragweed sensitivity, so they have fall hay fever, ragweed allergy, they tend to have problems with watermelon and related fruits. So, there's some associations with pollen allergy. So, sometimes you can predict what an oral allergy syndrome might be, but otherwise, we don't really have a way to test for them.

Melanie: So, your best advice about dealing with them, Dr. Johns.

Dr. Johns: So, if you choose to keep eating those fruits, I think that's a good idea -- or vegetables. If you want to avoid them, I tell people keep trying different fruits and vegetables. You'll find fruits and vegetables that don't bother you -- that don't induce the symptoms. I tell them if you would like to keep eating those fruits, cook them or freeze them or smoothie them. That's not really a verb, but when you run them through a blender with some yogurt and what have you -- that seems to reduce symptoms as well. So, if you do choose to keep eating them, there’re certainly ways to reduce your symptoms.

Melanie: Thank you so much, Dr. Johns, for being with us today. You're listening to the Well Cast with Allina Health, and for more information, you can go to allinahealth.org. That's allinahealth.org. This is Melanie Cole. Thanks so much for listening.