Climate Change & Allergies to Pollen
- For many, the arrival of spring signals the unwelcome return of seasonal allergies.
- A new analysis of existing research suggests that climate change is exacerbating these seasonal suffering.
- Seventeen of the studies reviewed indicated that pollen seasons are becoming longer and pollen concentrations are increasing due to climate change.
Climate Change Worsens Pollen Allergies, Studies Show
Table of Contents
For many, the arrival of spring signals the unwelcome return of seasonal allergies. Allergic rhinitis, commonly known as hay fever, is an inflammatory reaction of the nasal passages triggered by the immune system’s hypersensitivity to environmental substances like pollen.
A new analysis of existing research suggests that climate change is exacerbating these seasonal suffering. The review, led by researchers at the University of Washington, examined 30 articles published between 2000 and 2023 to investigate the link between rising temperatures and the intensification of allergy symptoms.
Longer, More Intense Pollen Seasons
Seventeen of the studies reviewed indicated that pollen seasons are becoming longer and pollen concentrations are increasing due to climate change. According to the research, rising levels of atmospheric carbon dioxide (CO2) are a important contributing factor.
“Atmospheric carbon dioxide favors the growth of certain plants and trees,which allows them to produce more pollen,” the authors wrote in their study,published in The Laryngoscope.
Juan José Zapata, president of the Clinical Aerobiology Committee of the Spanish Society of Allergology and Clinical immunology (Seaic), who was not involved in the study, noted that mild winter temperatures and spring rains have boosted plant growth and pollination. He added that environmental stress can cause plants to express proteins that act as allergens, leading to a more inflammatory response in allergy sufferers.
Future Projections Indicate Further Worsening
Retrospective studies included in the analysis point to an increase in the severity and duration of allergy seasons. Projection models suggest a potential 19% increase in the length of pollen seasons and a 16% to 40% increase in total annual pollen concentration.
“Even though we cannot predict exactly what will happen at each time of the year, we can observe the trends in the seasons of allergies,” the authors emphasized.
“These figures help us identify that the variation in pollen seasons is not small and can have continuous consequences for patients with allergic rhinitis,” they added.
Impact on Healthcare
The research also highlights the strain on healthcare systems. Four of the studies reviewed showed an increase in medical visits related to allergic rhinitis, particularly among low-income residents.Two other studies indicated a need for increased education among healthcare professionals regarding climate change and its impact on allergies.
“The climate crisis is aggravating allergic rhinitis,” the authors stated. “Its symptoms represent in themselves a significant problem for the quality of life. In addition, the worsening of this immune response also increases the risk of sinus infections and the growth of allergic asthma.”
One of the study’s lead authors emphasized the role of physicians in addressing the issue. “Doctors are in a privileged position to observe the impact of allergic rhinitis on patient results and can adapt their practice as climate change intensifies. Also, as trusted voices for the community, they should take advantage of their first-line experience to advocate for a significant change in the fight against this crisis.”
Zapata concurred, stating that “From the anthropogenic climate change produced by human activity, we are seeing answers in patients with a lot of mucosa more irritated and with greater possibilities of being damaged by certain allergens that are in the environment.”
The Development of Allergies
Allergies are the result of an exaggerated immune response to substances that are typically harmless. genetic predisposition and epigenetics, the study of how genes can change over time, both play a role in determining an individual’s susceptibility to allergies.
Individuals often experience an ‘allergic march’ throughout their lives, a sequence of allergies that can evolve over time.
“Children at months of age can have sensitivity to certain foods such as milk or eggs. Then they can present skin problems such as atopic dermatitis and begin to sensitize before allergens such as mites, polenes or fungi. this makes that sequence of allergies be configured,” Zapata explained.
However,allergic reactions can develop at any point in life. A significant number of allergies also emerge between the ages of 25 and 35.
“We are currently seeing phenomena that before they did not happen. Patients above 65 years they show sensibilities for the first time.Thus, developing an allergy will depend a lot on the external environment and the genetic impregnation that each patient has,” Zapata concluded.
Reference:
Pershad, A.,Tummala,N., et. al. How Climate Change Is Impacting Allergic Rhinitis: A Scoping Review. The Laryngoscope (2025)
Climate Change Worsens Pollen Allergies: A Q&A
| Question | Answer |
|---|---|
| What is allergic rhinitis, and what triggers it? | Allergic rhinitis, commonly known as hay fever, is an inflammatory reaction in your nasal passages. It’s triggered by your immune system’s hypersensitivity to environmental substances, with pollen being a common culprit. |
| How is climate change affecting pollen seasons? | A new analysis of research indicates that climate change is making pollen seasons longer and pollen concentrations higher. Rising levels of atmospheric carbon dioxide (CO2) are a major factor, encouraging the growth of plants and trees that produce pollen. Mild winter temperatures and spring rains also contribute by boosting plant growth and pollination. |
| What do the projections indicate about the future of allergy seasons? | Projection models suggest we can expect a potential 19% increase in the length of pollen seasons and a 16% to 40% increase in total annual pollen concentrations. |
| What impact is this having on healthcare systems? | Studies have shown an increase in medical visits related to allergic rhinitis, particularly among low-income individuals. ther’s a growing need for healthcare professionals to receive more education about climate change and its impact on allergies. |
| How is climate change contributing to more severe allergy symptoms and potential health issues? | The climate crisis is aggravating allergic rhinitis. the worsening of the immune response increases the risk of sinus infections and the progress or exacerbation of allergic asthma. |
| What role can physicians play in addressing this issue? | Doctors are in a prime position to observe the impact of allergic rhinitis and can adapt their practices. they also have a trusted voice in their communities and can advocate for significant changes to combat this crisis. |
| What is the “allergic march”? | The “allergic march” describes a sequence of allergies that can develop over time in an individual.It often starts with sensitivities to foods in early childhood, followed by skin problems like atopic dermatitis, and then sensitization to allergens like dust mites, pollen, or fungi may occur. |
| Are there any other points of contact in which allergies can occur? | Allergic reactions can develop anytime in life,but a significant number emerge between the ages of 25 and 35. We are seeing allergies develop in older adults for the first time (65+) because developing an allergy depends a lot on the external surroundings and a person’s genetic makeup. |
Reference: pershad, A., Tummala, N., et. al. (2025). How Climate Change Is Impacting Allergic Rhinitis: A Scoping Review. The Laryngoscope