Cross-Reactive Food Allergies

If you have a life-threatening reaction to a certain food,your health care provider will show you how to avoid similar foods that might trigger this reaction. For example, if you have a history of allergy to shrimp, allergy testing will usually show that you are not only allergic to shrimp but also to crab, lobster, and crayfish. This is called “cross-reactivity.”

Another interesting example of cross-reactivity occurs in people who are highly sensitive to ragweed. During ragweed pollen season, they sometimes find that when they try to eat melons, particularly cantaloupe, they experience itching in their mouths and simply cannot eat the melon. Similarly,people who have severe birch pollen allergy also may react to apple peels. This is called the “oral allergy syndrome.”

Common Food Allergies

In adults, the foods that most often cause allergic reactions include

• Shellfish such as shrimp, crayfish, lobster, and crab

• Peanuts

• Tree nuts such as walnuts

• Fish

• Eggs

The most common foods that cause problems in children are

• Eggs

• Milk

• Peanuts

• Tree nuts Peanuts and tree nuts are the leading causes of the potentially deadly food allergy reaction called anaphylaxis.

Adults usually keep their allergies for life, but children sometimes outgrow them. Children are more likely to outgrow allergies to milk, egg, or soy, however, than allergies to peanuts. The foods to which adults or children usually react are those foods they eat often. In Japan, for example, rice allergy is frequent. In Scandinavia, codfish allergy is common.