Why Do Adults Develop Allergies?
The sudden onset of allergies is frustrating, but common. It’s not always clear why some people develop allergies later in life. Genetics may play a role, as do changes in your over the course of your life. Adult-onset allergies occur most often in people in their 20s and 30s, though it’s possible to develop allergies at any age.
Moving to a new location is one common cause experts agree on. When you move to a new part of the country that has a variety of grass and trees you’ve never been exposed to, there’s a chance you can develop sudden outdoor allergies to your new environment.1
Allergies may also develop as your immune system changes. Your immune system’s tolerance to allergens may wane over time, or with age. You may lose tolerance to an when you lose or reduce your exposure to that allergen.2
For instance, you may have grown up surrounded by your family’s dogs and cats, and you may not have exhibited symptoms during this time. But once you move out and live on your own without pets, your immune system may lose tolerance to the allergens produced by pets. Returning home to see your childhood dog or cat may, sadly, trigger the onset of pet allergic reactions you’ve never experienced before.3