How Climate Change is Making Allergies Worse—And What Clinicians Can Do

As climate change intensifies, it is not just the environment that suffers—seasonal allergies are getting worse, too. Global warming has led to increased droughts, wildfires, intense storms, heat waves, and rising sea levels, factors that can contribute to allergies and asthma.¹

According to the American Public Health Association, the 3 main causes of allergy include ambient air pollution, mold, and pollen.¹ The organization also reported that 30% of adults and 40% of children experience nasal allergies.

At the 2025 American Academy of Allergy, Asthma, & Immunology (AAAAI) annual meeting in San Diego, HCPLive spoke with several experts on climate change’s impact on allergies, exploring strategies clinicians can adopt to mitigate worsening allergic conditions.

Expert Insights:

Sharmilee Nyenhuis, MD, from the University of Chicago

Mahboobeh Mahdavinia, MD, PhD, from the University of Texas Health Houston

Scott Commins, MD, PhD, from the University of North Carolina

Kent Lam, MD, from Eastern Virginia Medical School at Old Dominion University

Extended Pollen Seasons and Increased Allergen Potency

Nyenhuis emphasized that pollen seasons are lengthening, especially in the western and southwestern United States, where freeze days have increased by nearly 20.² This prolonged exposure intensifies symptoms and raises the risk of new allergies. She also noted that air pollution, particularly diesel particles, can amplify pollen’s allergenicity, worsening allergic reactions.

To help patients, Nyenhuis recommended indoor air filtration, wearing masks outdoors, and using hyper-local pollen data instead of historical weather app forecasts, which are becoming less reliable due to climate change.

Air Pollution’s Role in Allergy Development

Mahdavinia explained that air pollutants disrupt the respiratory tract’s epithelial barriers, leading to inflammation and microbiome imbalances in the nose and lungs.³ This can eliminate beneficial bacteria, allowing harmful microbes to thrive and increasing allergy risks. Mahdavinia called for expanded pollen monitoring and broader allergen testing as plant distributions shift.

Climate Change and Emerging Food Allergies

Commins discussed pollen food syndrome, in which pollen absorbed through the skin triggers food allergies.⁴ He also warned about the rising prevalence of alpha-gal syndrome, a meat allergy caused by tick bites. Warmer winters have expanded tick populations, increasing cases in the US, Europe, Australia, and Asia.

Clinical Takeaways

As climate change drives new allergy risks, clinicians must stay alert for evolving conditions such as pollen food syndrome and alpha-gal syndrome. Experts stress the importance of refining allergy diagnostics, improving access to immunotherapy, and implementing preventive strategies to protect patients in an increasingly allergenic environment.

Relevant disclosures include GlaxoSmithKline for Nyenhuis, GENZYME CORPORATION, Optinose US, Inc, and Blueprint Medicines Corporation for Mahdavinia, Regeneron Healthcare Solutions, Genetech USA, and AstraZeneca Pharmaceuticals for Commins, and Optinose US, AERIN MEDICAL, GENZYME CORPORATION, Medtronic, GlaxoSmithKline, Regeneron Pharmaceuticals, and AstraZeneca Pharmaceuticals for Lam.

Note: The narrator is AI-generated.

References

1. Climate Changes Allergies and Asthma. American Public Health Association. chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.apha.org/-/media/files/pdf/topics/climate/asthma_allergies.pdf. Accessed March 20, 2025.

2. Derman, C. Adapting Allergy Care Due to Increased Pollen Seasons, with Sharmilee Nyenhuis, MD. HCPLive. March 1, 2025. https://www.hcplive.com/view/adapting-allergy-care-due-increased-pollen-seasons-sharmilee-nyenhuis-md. Accessed March 20, 2025.

3. Derman, C. How Air Pollutants Contribute to Allergies, with Mahboobeh Mahdavinia, MD, PhD. HCPLive. March 1, 2025. https://www.hcplive.com/view/how-air-pollutants-contribute-to-allergies-with-mahboobeh-mahdavinia-md-phd. Accessed March 20, 2025.

4. Derman, C. Climate Change’s Impact on Allergies, with Scott Commins, MD, PhD. HCPLive. March 2, 2025. https://www.hcplive.com/view/climate-change-s-impact-on-allergies-scott-commins-md-phd. Accessed March 20, 2025.