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Oral Allergy Syndrome and Hay Fever: Facts and Connection

Linda Crampton is a writer and former teacher with a first-class honors degree in biology. She writes about the scientific basis of disease.

Hazelnuts are delicious and nutritious, but they can cause oral allergy syndrome.

Hazelnuts are delicious and nutritious, but they can cause oral allergy syndrome.

What Is Oral Allergy Syndrome?

Oral allergy syndrome (OAS) is a disorder in which the ingestion of a particular food causes an allergic response in the mouth. The most common symptoms of the disorder are a burning, itching, or tingling sensation in the lips, tongue, lining of the mouth, and throat. Oral allergy syndrome is generally less serious than a so-called "true" food allergy, which can cause a major and widespread allergic response. This isn't always the case, however.

Most people who experience OAS also suffer from hay fever. In fact, an allergy to pollen is believed to be responsible for most cases of oral allergy syndrome. Hay fever is caused by proteins in inhaled pollen grains that trigger an attack by the body's immune system. Some foods contain similar proteins to those in pollen grains and also trigger an immune system attack. The system is unable to tell the difference between the proteins in the pollen grains and the proteins in the food, a phenomenon known as cross-reactivity.

OAS can occur all year found, but for some people it's worse in the pollen season. Strategies to reduce or prevent both hay fever and OAS may be useful. Not everyone who suffers from hay fever experiences oral allergy syndrome, but it can be unpleasant when someone does. I have both of the disorders and find some of the techniques described below very helpful for relieving them.

Raw apples are a common cause of oral allergy syndrome.

Raw apples are a common cause of oral allergy syndrome.

Vegetables such as celery, carrots, tomatoes, and cucumbers can cause oral allergy syndrome symptoms in some people.

Vegetables such as celery, carrots, tomatoes, and cucumbers can cause oral allergy syndrome symptoms in some people.

Possible Symptoms of OAS

In many people, symptoms of oral allergy syndrome are localized and are restricted to the mouth. The first symptom listed below is most common and may be the only one that appears. OAS symptoms usually develop immediately after eating a food, but they may not develop until up to thirty minutes later or very occasionally up to an hour after eating the allergenic food.