Can You Develop Allergies as an Adult?

April 2022

You reached adulthood without suffering from allergies. And then suddenly one spring — or fall — you start sneezing every time you go outside. Strange as it may seem, you could be developing adult-onset allergies.

More than 19 million Americans 18 and over suffer from hay fever, the most common seasonal allergy. Not all of them developed allergies during childhood. For some people, it takes years of exposure to trigger an allergic reaction, so they don’t experience the sneezing, watery eyes, and runny nose of hay fever until later in life.

An allergy expert who is a former president of the American College of Allergy, Asthma, and Immunology explained to the Wall Street Journal that you might develop allergies as an adult if you:

  • Move to a new climate. Being exposed to new types of pollen or high levels of pollution can trigger allergic reactions. Climate change is making pollen season longer, which may also contribute to an overall increase in allergies.
  • Move into a house with high levels of mold. The Asthma and Allergy Foundation of America says that mold in basements, kitchens, and other rooms can trigger allergies and asthmas.
  • Are re-exposed to an old allergen. Sometimes it takes repeated exposures to have an allergic reaction, even if these instances are years apart. That could be why you’re sneezing around your new cat when you never had animal allergies before.
  • Are sick or pregnant. Any time your immune system is weak, you’re more susceptible to developing allergies.
  • Have a virus. A virus such as respiratory syncytial virus, which infects the lungs, or even the common cold, can weaken your body’s defense system, making you more likely to develop allergies. Once you’re feeling better, it’s likely that your allergies will diminish.

Allergies tend to go away when the trigger is removed.

The best way to cope with adult-onset allergies? Use the same strategies that experts recommend for all people with seasonal allergies: Avoid triggers whenever possible. And ask your doctor if over-the-counter medications or allergy shots may help.

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