A couple years ago, a friend confessed that he suspected he might be allergic to tomatoes; recently, he said, his mouth had started feeling just a little bit itchy whenever he ate them. I, in turn, confessed that I thought he sounded stupid. “That’s not how allergies work,” I told him, with the exaggerated eye roll of someone who’s convinced of their own rightness. “You’re probably imagining things.”
Well. One of us was certainly being stupid. As reporter Allison Aubrey recently explained in NPR, “oral allergy syndrome” is indeed a real thing — and the itches and tingles can develop in response to foods that have never posed a problem before.
The syndrome, which arises in response to certain raw fruits or veggies, is really a mild case of seasonal allergies gone haywire, Aubrey wrote:
People who have OAS are allergic to plant pollens. Many fruits and vegetables contain proteins that are similar to these pollens. So the immune system can mistake the fruit and vegetable proteins for the plant pollens that caused the allergy … The prevalence of oral allergy syndrome is unknown, but researchers who evaluated pollen-related food allergies in 2015 concluded: “Although epidemiologic data are scarce, there is no doubt that the increase in pollen allergies is going to be followed by an increase in the so-called pollen-related food allergies.”
Certain fruits and vegetables also correspond to different types of seasonal allergy, as this chart from the National Jewish Health Service explains: carrots and kiwis, for example, contain proteins most similar to the tree pollen that’s prevalent in the springtime; tomato and watermelon, among others, are closest to summer grasses; and apples and bananas are some of the items with proteins similar to those of autumn weeds.
Across the board, though, there are things that OAS sufferers can do to avoid itchy mouth: Cook your produce, or peel it, or, if you have a weakness for the offending fruit and just have to have it raw, pop an antihistamine first. And if you have a smug, skeptical friend, tell them that what you’re experiencing is a scientific, documented phenomenon — it won’t make your mouth feel any less weird, but it does feel good to be right.