Food Allergy and the Role of Components

Most of us are familiar with the types of foods commonly evaluated in patient’s with suspicious of food allergy based upon their symptoms. Peanuts get the most attention but as a specialist I and my colleagues will test for other common foods such as eggs, wheat, sesame, soybean, corn, tomato, shellfish, strawberry, chicken, meat and fish.

The list of foods we can test for are rather limitless and from time to time we have to test for more novel food-allergy-suspicious-characters such as avocado, pomegranate, mushrooms, etc.

But why is it that we often find two patients with similar food allergies who have vastly different severity of symptoms when exposed to the same food?

Well, it turns out that we don’t just react to the ‘whole’ foods but ‘components’ that make up those foods.

You see, our ‘allergy’ to foods is an immune response that mistakes protein molecules as foreign invaders. Foods are made of a collection of protein ‘components’ or building blocks. A reaction to these specific components seems to predict the severity of reaction and at least in part is responsible for the divergence of allergic responses in individuals with the same or similar test positives.

For eggs, milk, peanuts and an increasingly larger list of whole foods we can now test for the components. As time goes by I expect we will understand the offending component proteins for all of the major foods we test in an allergy specialty clinic!