Oral allergy syndrome (OAS) always sneaks up on me. This year, I was sitting in the dentist's chair having my teeth cleaned when suddenly my tongue started tingling and my throat start itching. OAS didn't even make the list of possible explanations I had for my symptoms. I thought, "What's going on here? Am I having a reaction to something the dental hygienist is using?"

It took until later when the symptoms persisted for the light bulb to go on and for me to realize, that yes, it was once again my least favorite allergy symptom, OAS. You too may be one of the "lucky" individuals who has OAS so I'm writing this to help you prepare for its arrival.

Many seasonal allergy sufferers with OAS experience an itching, tingling, burning or swelling of the lips, tongue, throat or mouth after eating certain raw fruits, vegetables or tree nuts. OAS occurs in about one-third of those with allergies. Adults are affected more than children. Symptoms tend to be worse during spring and fall pollen seasons.

You have to be a bit of a detective to figure out what's causing your OAS symptoms. In my case, it was fresh strawberries eaten during breakfast. During the grass pollen season, I get OAS symptoms after eating berries, celery and watermelon. Other trigger foods include peaches, tomatoes, oranges, cantaloupe and honeydew. But each year, I forget until I get the symptoms.

OAS symptoms result from a cross reaction between the protein in certain raw foods and plant pollens. Basically, OAS works like this. You eat something like a bowl of strawberries or a ripe tomato. Your immune system recognizes a similarity between pollens in the air and what you’ve just eaten and produces an allergic reaction, kind of a combined pollen-food attack.

In most cases, reactions are mild and occur within minutes of eating the offending food, and last a few seconds or minutes. Sometimes, symptoms may last for hours. Other symptoms may include watery and itchy eyes, runny nose and sneezing. Approximately nine percent of individuals have more severe symptoms, including gastrointestinal problems (nausea, diarrhea) or skin allergies (contact dermatitis, hives, itching). About two percent may experience anaphylaxis, a life-threatening response.

When the trees are pollinating, I can’t eat some of my favorite fruits and veggies without having an itchy throat. Ragweed season produces more of the same.

Cooking or processing the problem foods, in some cases, eliminates the reaction. You also can try peeling a fruit or veggie to see if that helps. An antihistamine, taken 30-60 minutes before eating an offending food, may provide relief.

Cross reactions are more likely with the following food and plant combinations:
•Grasses: tomatoes, potatoes, peaches, melon, oranges, celery.
•Ragweed: melons, bananas, cucumbers, zucchini, dandelion, chamomile tea.
•Birch: potatoes, carrots, celery, parsnips, peppers, cherries, apple, pears, plums, peaches, kiwi, apricots, fennel, parsley, coriander, hazelnuts, almonds, walnuts.
•Alder: celery, pears, apples, cherries, peaches, parsley, almonds, hazelnuts.
•Mugwort (a weed): celery, carrots, various spices, apples, kiwis, fennel, peanuts, sunflower.
•Any of the above may react with: strawberries, raspberries, blueberries, other berries, citrus, grapes, mango, figs, peanuts, pineapple, pomegranate, watermelon.

The treatment is simple. Eat your fruits and veggies cooked instead of fresh. In addition, antihistamines and allergy shots may lessen symptoms.