Oral Allergy Syndrome: Why Eating Honeydew (or Celery and Carrots too!) Can Make Your Throat Itch

How to cope — and when to be more concerned
Honeydew Melon Oral Allergy

You’re happily digging into a crisp fruit cup. Ah, refreshing honeydew and cantaloupe! But just a minute later, it hits you. Your throat is itchy, kinda tingling. What gives?

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No, you’re not imagining it. Allergist Martin Smith, MD, says the phenomenon you’re experiencing is called oral allergy syndrome, or food-pollen syndrome.

“It’s actually the most common type of food allergy in adults,” Dr. Smith says. “It’s a mild form of contact allergy to fresh fruits and vegetables in people who have hay fever.

“You’ll feel an itching, tingling, sometimes a mild fullness or swelling in your tongue, lips or back of your throat pretty soon after you start eating.”

Those with hay fever (also called allergic rhinitis) may be affected by several types of pollen — including ragweed, birch and grass. Possibly 50 to 75 percent of them may also be affected by food-pollen syndrome from spring through mid-September.

The offending triggers

Birch pollen (March & April): Pitted fruits (apple, peach, plum, pears), carrots, celery, almonds, hazelnuts.

Grass pollen (May to early July): Tomatoes, potatoes, melons, oranges.

Ragweed pollen (mid-August to mid-September): Melons (cantaloupe, honeydew, watermelon), zucchini, banana.

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Why it happens

Symptoms occur almost immediately after eating the offending food, usually in the cross-reacting pollen season. That means, Dr. Smith says, you will usually have less symptoms if you eat imported melon in January.

“The reason you get the sensation is because the protein in the uncooked fruit or vegetable is very similar to the pollen protein that’s found in birch, ragweed and timothy or orchid grasses,” he explains. “Your body kind of confuses the fruit protein to be the actual pollen from the birch tree, ragweed or grass.”

This causes irritation or swelling in the mouth that’s usually pretty mild. Any annoyance or discomfort disappears pretty quickly, Dr. Smith says, because your stomach acid rapidly destroys the offending protein once swallowed.

Usually, most pollen-food suffers can tolerate eating a small quantity of the fruits or other foods. If the symptoms are bearable and mild, there’s no harm in continuing to eat the food. But in some folks, the reaction is quite bothersome, and they usually can’t eat that food when the offending pollen is in season.

How serious is it? And what to do …

It’s important to point out that you can only get oral allergy syndrome if you’re allergic to pollen, Dr. Smith notes.

“You can only get it from food that comes from plants,” he says. “So you can’t get it from seafood, dairy, eggs or meat. And you usually only get it from the fresh, uncooked version of fruits and vegetables because the proteins in the foods that cause this syndrome are easily destroyed or changed when you heat the food.”

Most times, no treatment is needed. But Dr. Smith says there are two types of people who should see an allergist.

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First, those who have a reaction to nuts like almonds or hazelnuts. “You don’t want to confuse a mild food-pollen allergy with a more serious food allergy — which could be more severe the next time,” he says. And second, anyone who has systemic symptoms (this happens in less than 5 percent of food-pollen allergy suffers) like hives, vomiting, difficulty breathing, reactions that are getting progressively worse or if you experience symptoms when eating cooked versions of the foods.

“Otherwise, just avoid the raw fruits and vegetables in the relevant pollen season,” Dr. Smith advises. “So skip that watermelon in the middle of August.”

If you find avoiding your favorite foods tough in all three pollen seasons, you can talk to your allergist about allergy shots, he notes, which often help people tolerate the foods better.

Don’t want to bother? There’s two more options. You can peel the food to see if that helps you tolerate it better, though you might then experience tingling in your hands from contact with the skins, often seen with potatoes. Or, you can heat it up.

“Just put the fruit in the microwave for 10 seconds,” Dr. Smith says. “It doesn’t sound very appetizing, but it works a lot of the time.”

So nuke that next fruit cup? Your choice.

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