News — BOSTON (Oct. 24, 2024) – People have heard for years that climate change is having a significant impact on plant vegetation patterns and influencing how pollen and mold produce. A new study being presented at this year’s American College of Allergy, Asthma and Immunology (ACAAI) Annual Scientific Meeting in Boston showed that, in Chicago, there has been a significant increase in sensitization to pollens and molds in patients with nasal allergies.

“Our goal was to analyze changes in pollen sensitization patterns over the past 10 years in Chicago to better understand the impact of climate change on airborne substances that can cause an allergic reaction,” says allergy fellow Kylie Jungles, MD, lead author of the study and ACAAI member. “Airborne allergens include any substance that can cause an allergic reaction, such as pollen, mold or dust mites. We wanted to see if climate change showed an association with those substances in terms of increasing the rates of sensitization.”

Allergic sensitization is the process by which the body develops antibodies to allergens, which are components of substances normally occurring in the environment, that are inhaled, ingested, or absorbed. It is the first step in a person becoming allergic to a substance.

In the study, a retrospective chart review was conducted on patients with nasal allergies seen at an allergy center in Chicago from 2014-2024. Data from blood tests was collected, as well as patient specific characteristics including age, gender, and other allergic conditions. 

Allergen testing from 1,052 patients was analyzed from 2014-2019 (pre-COVID) and 2022-2024 (post-COVID.) The rate of sensitization to outdoor aeroallergens significantly increased in the post-COVID period compared to pre-COVID. Tree pollen (69.8% vs. 49.3%), weed pollen (76.1% vs. 54.1%), grass pollen (100% vs. 57.7%), and mold (76.7% vs. 46.5%) all increased post-COVID compared to pre-COVID. Despite the increased sensitization to outdoor allergens during these time periods, sensitizations to indoor allergens (cat and dog) were not significantly different. 

The authors conclude, “This increased sensitivity may be due to changing patterns of pollen and mold proliferation secondary to increased temperatures, rainfall, and rising water levels that Chicago has been experiencing due to climate change. More research is needed to investigate the impact of climate change on aeroallergen sensitization.”

Abstract Title: CHANGE OF SENSITIZATION PATTERNS TO POLLENS OVER THE PAST DECADE
(Full abstract below)

Presenter: Kylie Jungles, MD 

For more information about food allergies, or to find an allergist in your area, visit The ACAAI Annual Scientific Meeting is Nov. 9-13. For more news and research from the ACAAI Scientific Meeting, go to our and follow the conversation on X/Twitter

About ACAAI

The American College of Allergy, Asthma & Immunology (ACAAI) is a professional medical organization of more than 6,000 allergists-immunologists and allied health professionals, headquartered in Arlington Heights, Ill. Founded in 1942, the College fosters a culture of collaboration and congeniality in which its members work together and with others toward the common goals of patient care, education, advocacy, and research. ACAAI allergists are board-certified physicians trained to diagnose allergies and asthma, administer immunotherapy, and provide patients with the best treatment outcomes. For more information and to find relief, visit . Join us on , , and X/Twitter. 

R337
CHANGE OF SENSITIZATION PATTERNS TO POLLENS OVER THE PAST DECADE
K. Jungles*1, K. Singh1, S. Armana1, C. Juarez1, S. Pacheco2, M. Mahdavinia2, 1. Chicago, IL; 2. Houston, TX.

Introduction: Climate change is a growing and urgent public health concern. In the field of Allergy and Immunology specifically, there is concern that climate change is impacting plant vegetation patterns, thereby influencing patterns of pollen and mold proliferation. We aimed to analyze changes in pollen sensitization patterns over the past ten years to further understand the impact of climate change on aeroallergen sensitization. 

Methods: A retrospective chart review was conducted on patients with allergic rhinitis (AR) seen at a tertiary care center in Chicago from 2014-2024. InVitro aeroallergen data was collected, as well as patient specific characteristics including age, gender, and atopic comorbidities. 

Results: InVitro aeroallergen testing from 1,052 patients was analyzed from 2014-2019 (pre-COVID) and 2022-2024 (post-COVID.) Interestingly, the rate of sensitization to outdoor aeroallergens significantly increased in the post-COVID timeframe compared to pre-COVID. Tree pollen (69.8% vs. 49.3%), weed pollen (76.1% vs. 54.1%), grass pollen (100% vs. 57.7%), and mold (76.7% vs. 46.5%) all increased post-COVID compared to pre-COVID. Despite the increased sensitization to outdoor allergens during these time periods, sensitizations to indoor allergens (cat and dog) were not significantly different. 

Conclusion: There has been a significant increase in sensitization to pollens and molds in patients with AR living in Chicago over the past decade. This increased sensitivity may be due to changing patterns of pollen and mold proliferation secondary to increased temperatures, rainfall, and rising water levels that Chicago has been experiencing due to climate change. Additional research is needed to investigate the impact of climate change on aeroallergen sensitization.