Definition: Sensitization is the production of a specific type of allergic antibody by the immune system resulting in a positive allergy test, such as to a particular food or pollen. It is possible for a person to make a specific allergic antibody to a food, for example, without experiencing allergic reactions when that food is eaten.
Examples: Sensitization to multiple foods is common in people with nasal allergies, although a person may still be able to eat those foods without apparent symptoms. Therefore, food allergy tests can often result in false positive reactions in people with multiple allergies.

