British Columbia

Never-ending allergies? Blame multiple pollen seasons

A Vancouver-based allergist says that some allergy sufferers can experience a resurgence of their symptoms in May and June when both tree and grass pollen are floating around.

Allergist says overlapping tree and grass pollen can make symptoms last all summer

Grass pollen starts accumulating as early as May and can last until the end of the summer. (Dale Molnar/CBC News)

A change of pollen in the air might explain why you've been feeling sneezy for the past couple of weeks as the tree allergy season ends and grass season begins.

Dr. Donald Stark, an allergist at the University of British Columbia's faculty of medicine, says the transition can cause symptoms to flare in May and June.

"There's still tree pollen in the environment and people are allergic to tree pollen as well as grass pollen and the combination can be a problem," Stark said.

For unlucky allergy sufferers like Max Arthur, who lives in Abbotsford, B.C., it can mean dealing with symptoms all spring and summer, from March through July.

"Copious stuff coming out of my nose, my eyes water and burn almost constantly and then at night my sinuses seize right up," Arthur said.

He found out he was sensitive to both tree and grass pollen through allergy testing, but the results were far from comforting.

"It's kind of disheartening," he said. "Because you're allergic to grass, trees and what are you gonna do?"

Genetics and exposure

Stark says allergies to specific pollens often develop in people who have an allergic predisposition based on their family genetics.

"Your chance of developing allergy problems is likely higher, and you have to be exposed to an allergen first before you get reactions," he said.

The first exposure may not result in symptoms, he said, but it can trigger your immune system to produce allergy antibodies. Over the years and with subsequent exposure to the allergen, your body becomes sensitized and enough antibodies are present to trigger symptoms.

Stark says that's why repeated exposure can make allergies worse rather than help you get used to them.

Irritants increase sensitivity

Poor air quality from wildfire smoke in B.C. could make things worse throughout the summer.

"If someone is exposed to a variety of irritants there, they're exposed to dust or chemicals or even smoke, their airways are more likely to be twitchy to start with," said Stark.

The allergist recommends avoiding tasks like lawn mowing and suggested taking over-the-counter antihistamines to limit symptoms.

Allergen monitoring stations in B.C. are forecasting very high levels of pollen in Victoria over the next week as the two seasons overlap. In Vancouver and Kelowna, pollen levels are still moderate.


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