Do you ever get an itchy mouth when eating watermelon or cantaloupe? What about that luscious peach that left your gums raw and irritated?
Could be you’re one of millions whose pollen allergy also sets them up to react to certain foods.
It’s called oral allergy syndrome (OAS) and what’s behind it are similarities among some pollen-producing plants and related fruits and vegetables. For instance, a person who gets a runny nose or drippy eyes when exposed to ragweed pollen in the air might develop an itchy, tingling mouth or lips when eating foods with similar proteins.
For ragweed, that includes banana, chamomile, cucumber, echinacea, melon (watermelon, cantaloupe, honeydew), sunflower seed and zucchini.
New York allergist Clifford Bassett, MD, says as many as one out of every three people with seasonal allergies may experience oral allergy syndrome. The exact number is unclear because the condition often goes undiagnosed. Symptoms can be mild and go away quickly, making it less likely that people will see a doctor for diagnosis. Or parents might not associate a child’s dislike of a vegetable with an allergic reaction.
Symptoms can also seem quite random. For instance, many people are only bothered during pollen season; the rest of the year they can eat pollen-related foods with no problem. So if you’re allergic to ragweed, a melon in February (when ragweed is dormant) may not bother you at all, while one in September (when ragweed pollen counts are high) could set off symptoms with the first bite.
Dr. Bassett says some people with OAS will react to fresh foods but not cooked or canned varieties. If you have grass allergy, for instance, you may be able to eat tomato sauce on pizza but develop itchy mouth from fresh tomato in a salad. Others may find they can eat certain varieties of a fruit (Macintosh apples versus Granny Smith, for instance) or fruits without their skins.
In addition to itchiness and irritation, OAS symptoms can include mild swelling or hives in or around the mouth. While most will go away when you stop eating the food, Dr. Bassett says it’s a good idea to see an allergist for an individual consultation any time you experience allergy symptoms related to food.
Food-related symptoms can sometimes alert you to a more dangerous allergy, such as latex. A board-certified allergist can give you an accurate diagnosis, advise you which foods to avoid and recommend treatments to relieve symptoms.
Oral Allergy Syndrome is particularly common among people allergic to ragweed – some 36 million people in the U.S. – but it also affects people with other allergies. Researchers have identified specific foods that relate to birch, grasses and ragweed.
Birch pollen: almond, apple, carrot, celery, cherry, hazelnut, kiwi, peach, pear, plum, potato, pumpkin seed
Grass pollen: kiwi, melon, peach, tomato
Ragweed pollen: banana, chamomile, cucumber, echinacea, melon (watermelon, cantaloupe, honeydew), sunflower seed, zucchini
First published: The MA Report, October 2007
Revised: February 2009