Seasonal Allergies and the Foods Triggering Oral Allergy Syndrome

Seasonal allergies affect about 20 percent of the US population, research has shown. As it must already be known, they manifest by sneezing, itchy eyes and nose, and sinus congestion. Of these people, another 25 percent also suffer from oral allergy syndrome (OAS), which is not the same with food allergy, but does come with several very unpleasant effects.

OAS is cross-active, specialists say, meaning having OAS to, say, nuts, is not the same as being allergic to nuts in general, although people suffering from the latter may have OAS as well. However, OAS only becomes obvious after suffering from hay fever or a similar allergic reaction to pollen, health experts explain. This happens because the immune system becomes sensitive to pollen – the allergen – and then interprets the proteins in certain foods, vegetables or nuts as similar to the pollen protein, which sets off the allergic reaction.

“Oral allergy syndrome (OAS) is an allergic reaction to fruits, vegetables and nuts caused by an individual’s similar allergy to pollen (small, powdery grains that are the fertilizing element of flowering plants, much of which can easily become airborne). The cross-reaction between the two is the result of similarities in proteins found in some types of pollen and in some fruits, vegetables and nuts. Also known as pollen-food syndrome, the reaction causes itching and swelling in the mouth, throat and lips when a certain fruit, vegetable or nut is consumed.” Your Total Health says of this special type of allergy.

Nevertheless, research has shown that only when the fruits or vegetables are consumed in a certain way they create an allergic reaction. For instance, a person who develops OAS from eating a raw apple (be it organic or traditionally grown) can enjoy a slice of apple pie, drink apple juice or eat canned (and boiled) apples without having any of the symptoms mentioned above. The same goes for vegetables, which can even be frozen before cooking without triggering any adverse reaction. In the case of OAS to nuts, though, there is no way to avoid it than by not eating them at all, experts also say.

Usually, OAS symptoms are relatively mild and last for about 10 to 30 minutes before subsiding altogether. Nevertheless, as with hay fever and pollen allergies as well, OAS must not be ignored, since cases with severe consequences have been known to happen, health professionals warn. “While an OAS reaction is usually mild, highly sensitive people can experience life-threatening anaphylactic shock. This condition is characterized by a constriction of the airways that makes breathing difficult. OAS can also trigger an asthma attack in sensitive individuals.” the aforementioned medical publication states.