A Answers (1)
Mehmet Oz, MD, Cardiology, answeredYou can develop allergies or sensitivities at any point in life. An allergic reaction will not be apparent until you are exposed to the allergen. For example, if you have never lived with a pet, you may not know you are allergic until you actually have exposure to the animal you are allergic to. If you've lived in a tropical climate, you may not experience an allergic reaction to the ragweed of the northeastern United States until you are exposed to it.