Approximately one-quarter of adults (26%) and 19% of children in the United States grapple with seasonal allergies, commonly known as “hay fever,” caused by airborne plant pollen and mold spores, as reported by the Centers for Disease Control and Prevention. These allergies trigger immune responses that mimic infectious agents, resulting in symptoms like runny noses, itchy eyes, or scratchy throats, akin to a cold. For individuals with asthma or respiratory conditions, the reaction can escalate, necessitating medical attention.
Emerging research underscores the impact of climate change and greenhouse gas emissions on allergy seasons in the U.S. Warming temperatures, altered seasonal patterns, and increased atmospheric carbon dioxide are contributing to longer and more intense allergy seasons. The link between climate change and seasonal allergies is becoming more evident, with rising temperatures and extended freeze-free days exacerbating the concentration of allergens in the air.
A recent study spanning from 1990 to 2018 found that North American pollen seasons extended by an average of 20 days, with a 21% increase in concentrations. Human-induced warming accounted for approximately half of the shift toward earlier pollen seasons and about 8% of the rise in spring pollen concentrations during this period. This prolonged exposure intensifies allergenicity, affecting individuals susceptible to ragweed, mold, and tree and grass pollen—common triggers for seasonal allergies.
While the impact of climate change on mold allergens is less studied than that of pollen, warmer and wetter conditions are likely to enhance conditions for mold growth. The outdoor mold’s specific effects necessitate further research to provide a comprehensive understanding.
Research analyzing various cities revealed that 85% (172) experienced lengthened freeze-free seasons, with 31 cities witnessing a season extension of at least a month. Reno, Nevada, notably saw a 99-day increase—an among the highest in the country.
Antihistamines, a popular treatment for allergies, constitute a substantial global market, valued at approximately US$ 263.9 billion in 2022, with an expected growth to US$ 647.7 billion in the next decade. Despite their widespread use in alleviating asthma and allergy symptoms, antihistamines do not address the root cause of the diseases. Prolonged usage, exceeding a year, can lead to unpleasant side effects, including urinary retention, narrow-angle glaucoma, or antihistamine allergies.
In contrast, though, immunotherapy presents a paradigm shift from conventional symptom-relieving medications. It addresses the root cause, providing lasting relief for many years. Modern methods, such as sublingual immunotherapy, allow individuals to self-administer allergy drops at home, eliminating the need for weekly doctor’s office visits. This approach proves equally effective and more cost-efficient. As seasonal allergies become more prolonged and intense, immunotherapy emerges as a solution to mitigate their adverse health impacts.
