Oral allergy syndrome (OAS) is an allergy to certain raw fruits and vegetables, such as apples, cherries, kiwis, celery, tomatoes, and green peppers. OAS occurs mostly in people with hay fever, especially spring hay fever due to birch pollen and late summer hay fever due to ragweed pollen.
Eating the raw food causes an itchy, tingling sensation in the mouth, lips, and throat. It can also cause swelling of the lips, tongue, and throat; watery, itchy eyes; runny nose; and sneezing. Just handling the raw fruit or vegetable may cause a rash, itching, or swelling where the juice touches the skin.
Cooking or processing easily breaks down the proteins in the fruits and vegetables that cause OAS. Therefore, OAS typically does not occur with cooked or baked fruits and vegetables or processed fruits, such as applesauce.
back to top
Exercise-induced food allergy requires more than simply eating food to start a reaction. This type of reaction occurs after someone eats a specific food before exercising. As exercise increases and body temperature rises, itching and light-headedness start, hives may appear, and even anaphylaxis may develop. Some people have this reaction from many foods, and others have it only after eating a specific food.
Treating exercised-induced food allergy is simple—avoid eating for a couple of hours before exercising.
Crustacean shellfish, alcohol, tomatoes, cheese, and celery are common causes of exercise-induced food allergy reactions.
Last Updated February 08, 2012
Last Reviewed November 08, 2010