Yes, Adults Can Develop Seasonal Allergies

New York Times

18-03-2025

After decades of never experiencing seasonal allergies, you suddenly find yourself sneezing and sniffling along with the tens of millions of Americans who suffer from them. What happened?
'People tend to think of allergies as a childhood thing' and not something they can get later in life, said Dr. Tolly Epstein, an adjunct assistant professor at the University of Cincinnati College of Medicine who researches allergies and immunology. But 'it's very common to develop new allergies,' especially in your 20s, 30s and 40s, she said. And the symptoms aren't always obvious.
Most people with seasonal allergies will have sneezing, itchy eyes or nasal congestion. But those can also be accompanied by fatigue, a headache or sinus pressure — which, if you've never faced allergies before, you might mistake as cold symptoms, Dr. Epstein said.
If you've recently developed a pollen allergy, you might also experience itching in your mouth after eating certain raw fruits and vegetables, said Dr. Andrew Rorie, an assistant professor in the Division of Allergy and Immunology at the University of Nebraska Medical Center. That's because the immune system sometimes confuses proteins in the plants for pollen proteins, he said.
What causes seasonal allergies to develop?
Seasonal allergies are reactions to environmental elements like pollen or mold spores that tend to swirl around in the air during certain times — such as in the spring, when plants pollinate. When you're allergic to something like pollen, your immune system perceives it as a threat and triggers a chain reaction at the point of exposure. Antibodies in the nose or lungs stimulate the release of chemicals like histamine, which can lead to the sneezing, runny nose or congestion.
Scientists aren't exactly sure why you can develop new allergies or symptoms without ever having had them before, but there are several potential causes. For one, climate change is causing allergy season to start earlier and last longer, so it makes people more prone to developing symptoms, experts said.
In addition, some infections (like colds) could compromise protective mucous membranes, which could in turn weaken the body's ability to keep allergens from triggering the immune system, said Dr. Alkis Togias, a branch chief at the Division of Allergy, Immunology and Transplantation at the National Institute of Allergy and Infectious Diseases.
Where you live, and how long you've lived there, may matter as well. For some people, moving to a new place can bring a reprieve, if they're no longer exposed to the allergens that used to trigger their symptoms. But for others, it can introduce new problems, said Dr. Caroline Sokol, a principal investigator at the Center for Immunology and Inflammatory Diseases at Massachusetts General Hospital. Some may see their seasonal symptoms initially disappear — typically for about three to five years. 'Then all of a sudden, the allergies come back in full force,' she said. 'But now they're directed against new pollens.'
Living in the same place for a long time can also factor in. Prolonged exposure to irritants like pollen may actually increase the risk of allergies, as the body gradually builds an immune response to a substance it continually encounters, Dr. Sokol said.
There's also some early research to suggest that hormonal fluctuations might affect one's allergic response. But it's not always for the worse — for example, while some pregnant women see allergy symptoms become more severe, others see them improve, Dr. Rorie said. Menopausal women may have fewer allergy symptoms than they used to, possibly because of hormonal changes, along with the declining immune response that tends to come with older age.
How do you know if it's really allergies, and what can you do about it?
Seasonal allergies can affect people's quality of life, including their mood and their productivity at work, Dr. Togias said: 'Whatever they're doing, they're not going to do it well.'
But allergists are quick to point out that sneezing and runny noses — even during the spring — aren't necessarily caused by allergies. Technically, an allergy requires an immune system response. It's possible for an irritating substance like pollen or pollution to just trigger nasal inflammation without your immune system ever kicking into gear. If that's the case for you, it might mean that allergy medications won't ease your symptoms very much, Dr. Sokol said.
If medications do work, or if you consistently experience symptoms on days with high pollen counts, there's a good chance your suffering is caused by a seasonal allergy, she said.
There are widely available treatments to help alleviate symptoms, including over-the-counter antihistamines and nasal steroid sprays. Many allergists also offer immunotherapy, such as allergy shots, that gradually expose you to allergens like pollen or ragweed to reduce your body's reaction.
Beyond medication, there are a few simple steps you can take to minimize your discomfort, said Dr. Jonathan Spergel, chief of the allergy program at the Children's Hospital of Philadelphia.
Right when you get home, 'wash your hands and face' to rinse off any allergens, he said. Take a shower before going to bed, and sleep with the windows shut, he added: 'Those common sense things that Grandma told you.'