Do some foods cause your mouth and throat to itch, and maybe your lips and mouth to swell a bit, too? Is it worse at certain times of the year? If you have fall hay fever to ragweed, have you noticed eating bananas, cucumbers and melons such as watermelon, cantaloupe and honeydew make your mouth itch? Or do you notice the same symptoms when you drink chamomile tea? You may notice itching after eating raw vegetables like zucchini, but not if they’re cooked. You may have thought that if you had a food allergy you would have itching and hives all over your body, which could progress to anaphylaxis, a life-threatening reaction. So how can just an itchy mouth be a food allergy?
[See: 8 Surprising Facts About Asthma and Seasonal Allergies.]
If the above describes what happens to you in the fall, you might have oral allergy syndrome. In fact, people with spring allergies can also have OAS. So let’s get a better understanding of exactly what OAS is, how it’s diagnosed and how you should treat it.
OAS, sometimes called pollen-food syndrome, is an allergic reaction that occurs when certain foods touch the mouth, lips and throat. It’s usually seen in people with allergies to pollen like ragweed, trees and grasses, and it occurs when they eat certain foods, especially raw fruits and vegetables. Interestingly, this condition is more likely to affect adults than children.
Why does this happen to certain people with pollen allergies? It’s due to plant proteins in the pollen that cross-react with plant proteins in certain fruits and vegetables. This is why, when someone allergic to ragweed eats a banana, their immune system sees the two as related. This leads to an allergic reaction in your mouth, with itching or swelling as the most common symptom. These symptoms usually occur within minutes of eating the offending food and are generally worse during the particular pollen season. Depending on which pollens you are allergic to, there are different foods that can cross-react.
[See: Is it Healthy to Sleep With Your Pets?]
| Pollen | Food |
| Ragweed | Bananas, Melons (watermelon, cantaloupe and honeydew), Cucumber, Zucchini, Chamomile Tea |
| Grasses | Peaches, Oranges, Tomatoes, Celery |
| Birch tree | Apples, Potatoes, Pears, Peaches, Cherries, Carrots, Almonds, Walnuts |
| Mugwort | Broccoli, Cabbage, Cauliflower, Carrot, Celery, Mustard, Fennel |
How do you determine if you have OAS? Usually, it’s clear from your history. If you’re allergic to ragweed and get an itchy mouth after eating a banana in the fall, you have OAS. If your history is not cut-and-dried, seeing a board-certified allergist for evaluation can be valuable. An allergist may perform allergy testing and/or oral food challenges to raw fruits and vegetables to help isolate the cause of your problem and suggest proper management. You can find a board-certified allergist in your area by using the locate an allergist tool on the American College of Allergy, Asthma, and Immunology website.
In most people with OAS, there’s no need for medical treatment. You just need to avoid the offending food(s). Often, peeling or cooking the food will reduce or completely eliminate your symptoms. By cooking the food, you alter the offending protein so the immune system fails to recognize it as the same as the pollen.
[See: 7 Lifestyle Tips to Manage Your Asthma.]
You can use an oral antihistamine for OAS if the symptoms bother you. If you have severe recurrent OAS, you may be a candidate for immunotherapy injections (allergy shots) or immunotherapy tablets. The shots or tablets will not only control your hay fever symptoms but may also reduce the ones due to the food. In rare cases, people with OAS can develop anaphylaxis to the food, which is a life-threatening emergency. Those people must completely avoid the food, even if cooked or peeled, and carry an epinephrine auto injector. Be sure to see a board-certified allergist if your OAS is more than just a nuisance, as proper evaluation and management are important for controlling the condition.
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Why Your Mouth Itches When You Eat Certain Foods in the Fall originally appeared on usnews.com
