As autumn arrives and outdoor activities increase, allergy risks also rise due to seasonal changes in allergens. Dr. David Corry, professor of immunology, allergy and rheumatology at Baylor College of Medicine, explains the differences that fall brings compared to other seasons.
“The main issue driving the differences in the fall compared to other times of the year is the pattern of weather and nature of the allergens in the air,” Corry said.
During this time of year, ragweed pollen is especially prevalent. Mold spores are also common because of cold fronts that contribute to increased mold presence in the air. “Cold fronts drop the moisture and make the ragweed grow. High winds kick up, carrying the spores and pollen into the air,” Corry said.
Humidity supports mold growth during spring and summer. However, as cold fronts bring drier air in autumn, fungal growth slows down while spore production increases. “This really begins to take off as air dries out and humidity is limited,” Corry said. “They can’t grow without humidity, so they switch to other activities, which is making spores. With the dryness and winds kicking up, the spores are perfectly posed to get in the air and stay in the air.”
Allergy symptoms may include sneezing, nasal congestion, itchy eyes, or a runny nose. Differentiating between allergies and illness can be challenging; however, systemic symptoms like feeling run down or experiencing muscle aches may indicate a viral infection rather than allergies. “It’s a matter of degree of these symptoms, and it becomes more obvious over time,” he said.
To manage symptoms, Corry recommends using non-sedating oral antihistamines daily; some people may need two doses for severe cases but should not exceed this amount without physician advice. Nasal sprays with steroids or inhaled antihistamines can also help reduce inflammation and deactivate allergy-causing cells.
For persistent or severe allergies, immunotherapy may be necessary: “Go to your allergist to do specialized testing to determine what you’re allergic to. Once that’s known, you can get injections over time to reconfigure your response to those agents,” Corry said.
When participating in outdoor activities like visiting pumpkin patches or open fields—where exposure to ragweed and grass is likely—protective clothing such as boots, long pants, long sleeves, and even N95 masks for sensitive individuals is recommended. After outdoor exposure, removing clothes immediately and showering can help remove pollen from skin.
“Pollens will be all over you, and if you don’t get them off, they will work their way deeper into your skin and you might wipe them into your eyes, causing irritation,” he said.
Nasal rinses using sprays or Netti pots are also suggested for relief.
Inside homes, controlling indoor allergens involves using HEPA filters in main rooms as well as vacuum cleaners with HEPA attachments. Regular cleaning helps reduce pollen accumulation indoors. Regulating indoor humidity between 35-50% prevents mold growth; levels above 60% encourage mold development on surfaces throughout homes. According to Corry: “You have to know what your humidity is on the inside of your home and regulate it.” A good air conditioning system can help maintain proper humidity levels throughout fall.
