Prevalence of allergies in kids with asthma remains stable despite climate change

Children with asthma living in Los Angeles did not demonstrate an increase in allergic sensitization to inhalant allergens from 1999 to 2014 despite the growing impact of climate change, according to results of a retrospective cohort study.

“Our original thought was that with global warming and greater pollen counts and longer pollen seasons, we would see an increase in allergen sensitization over time,” Lyne G. Scott, MD, associate professor of pediatrics, allergy and immunology division chief, and allergy and immunology fellowship training program director at University of Southern California Keck School of Medicine, told Healio. “But, when we looked over the past 15 years we actually didn't see any increase in sensitization rates.

“That being said, it's really important to understand that, because sensitization does not equate to severity, those people who do have allergies might be having more intense symptoms and symptoms for longer,” she added. “We didn't find that those people who are not prone to developing allergies actually developed them.”

To evaluate their hypothesis, Scott and colleagues evaluated whether sensitizations to seasonal and perennial allergens increased from 1999 to 2014 among 5,874 children living in the greater Los Angeles area who were diagnosed with asthma by a specialist. The children underwent 123,209 skin prick tests to dust mites; cat; dog; cockroach; and tree, grass and weed pollen.

Overall, results presented at the American College of Allergy, Asthma & Immunology Annual Scientific Meeting showed that more children were sensitized to dust mites and cockroach compared with the other tested allergens.

However, researchers observed no significant increase in the prevalence of allergic sensitization to any of the perennial or season allergens, including pollen, over the 15-year period.

Scott said that she and her colleagues were surprised by their findings, and they are looking to confirm their findings on a larger scale.

“One of the things that was interesting for us to do this study is because Los Angeles is mostly in a growing season all year round,” she said. “That we were in more of an urban environmental may be one thing that contributed to these results.”

Reference:

• Despite climate change, kids with asthma in Los Angeles didn’t have an increase in allergy diagnoses. https://annualmeeting.acaai.org/2021/kids-with-asthma.cfm. Published Nov. 5, 2021. Accessed Nov. 5, 2021.