An allergist weighs in on how often people discover allergies past childhood
On Tuesday, hours before her concert in Tampa, Ariana Grande was forced to postpone the show after a sudden allergic reaction to tomatoes. The singer was as surprised as anyone — she had never had a problem with tomatoes before.
“Update: we discovered ….. that ….. i had an unfortunate allergic reaction to tomatoes and my throat pretty much closed. still feels like i’m swallowing a cactus but slowly making progress!” Grande, 25, wrote on Instagram, explaining that she also had to postpone her show in Orlando on Wednesday.
She added: “p.s. there is NOTHING MORE UNFAIR THAN AN ITALIAN WOMAN DEVELOPING AN ALLERGY TO TOMATOES IN HER MID TWENTIES…….”
While discovering a new food allergy well past the childhood years may seem surprising, it’s not uncommon, Thomas Casale, professor of medicine and pediatrics at University of South Florida and chief medical advisor for Food Allergy Research & Education (FARE), tells PEOPLE. But, he says, the problem is typically not with the food itself, but with pollen on the food.
“People are allergic to pollens, and those pollens have certain proteins that are similar in structure to proteins in various foods, so when you eat the food, you could have a local, allergic-type reaction, and a local reaction would be affecting your mouth and throat and lips,” he says. “It’s called oral allergy syndrome, or pollen food syndrome, and this tends to occur more commonly in older children and younger adults.”
Casale says he sees this fairly frequently in his practice, and is most likely what happened to Grande.
“Oftentimes we’ll see patients and they’ll say that they ate some food and they’re allergic to it, but most likely they’re not allergic to it and it’s that they’re allergic to something like birch pollen,” he says. “Then that creates a problem with fruits like apples and cherries, and leads to a reaction with itchiness in the mouth.”
Luckily, these oral allergy syndrome reactions are not as severe as the full anaphylaxis that are trademarks of peanut allergies.
“It’s uncommon for people with this oral allergy syndrome to have anaphylaxis, where it will affect organ systems outside of the mouth and throat,” Casale says. “It’s very rare.”
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In most cases, people will go back to normal in a few hours.
“These reactions tend to go away by themselves — they tend to be relatively short-lived, because the acids in your stomach break down those proteins and that’s usually the end of the reaction,” he says. “The treatment is avoidance. And oftentimes they can tolerate the vegetable or fruit if it’s microwaved or cooked, but not if it’s raw.”
Casale says that if people are unsure if they have a full allergy to a food or if it’s oral allergy syndrome, they should go to an allergist “to pin down the diagnosis.”
“About 75 percent of people develop their pollen and traditional allergens by their mid-20s, so it’s less common but does happen,” he says. “It’s important to keep in mind, because it could develop at any age.”