Sometimes adults suddenly develop allergies to foods they have eaten since they were children. Experts have two explanations for food allergies that crop up in adulthood. They may be the result of a delayed or extended period of sensitization to an allergen or a cross-reaction to some other allergen, such as pollen. The body's immune system mistakes a protein for the pollen and initiates a reaction.
To continue reading this article, you must login
Subscribe to Harvard Health Online for immediate access to health news and information from Harvard Medical School.