For the first time, scientists have found that measuring airborne allergen levels, instead of the traditional method of pollen count, will dramatically help hay-fever sufferers pre-empt risk and combat debilitating symptoms.
Hay fever, or seasonal allergic rhinitis, affects more than a quarter of US adults and around 19% of children. While symptoms such as sneezing, sinus pressure, itchy mouth and eyes and congestion have a lot in common with a cold virus, they’re instead triggered by pollen from trees and grasses. They can also impact the severity of symptoms for asthmatics, heightening wheezing, breathing difficulties and risk of attacks.
Researchers led by a team at King's and Imperial College London have, for the first time, found a more accurate way to determine to what degree pollen in the air on any given day will affect someone with hay fever.
“Grass pollen is the most common hay fever trigger,” said first author Elaine Fuertes, from Imperial College London. “In this study, we measured grass allergen (Phl p 5) levels and found this was more consistently associated with allergic respiratory symptoms than grass pollen counts.”
A pollen count is generally done by the physical real-time measurement of pollen in a given volume of air, sampled by a Rotorod device. This, along with pollen forecasts – which estimate allergy risk based on previous years’ data – have been the go-to methods for analyzing air quality around the world. But they’re far from ideal.
Because each pollen grain releases a different amount of allergen, a traditional pollen count can misrepresent the volume of symptom-triggering airborne allergens that are circulating on any given day.
The scientists argue that by instead measuring Phl p 5, a more accurate picture of active allergen content can be gained, allowing for hay fever sufferers to make more informed decisions regarding treatment and lifestyle.
In the study, researchers gathered daily symptom and medication scores from 93 PollenLITE clinical trial participants and asthma hospital admissions in London. They matched this with air samples that matched days and locations, measuring Phl p 5 grass allergen protein content.
Through blood analysis, symptom reports and medication use, the researchers found that while there was a link between daily pollen count and severity of allergic reaction, there was a much more consistent and accurate connection when measuring Phl p 5 levels.
While it’s still hard to accurately forecast allergy risk, incorporating Phl p 5 assessments may be more accurate than standard pollen counts.
“High pollen season can be serious for people who suffer with hay fever, and can trigger severe asthma attacks in those who are allergic to grass pollen,” said senior author Stephen Till, a professor of Immunology & Microbial Sciences. “This study shows there is a superior way of measuring pollen allergens in the air than the traditional pollen count."
The researchers will now investigate whether conditions such as temperature, wind, humidity and pollution have an impact on how much allergen each pollen grain releases.
“Monitoring grass allergen instead of grass pollen counts gives results that are more consistently linked to patients’ symptoms and could allow people with serious allergies to be better prepared during the pollen season,” Till said.
The research was published in The Journal of Allergy and Clinical Immunology.
Source: King's College London