Warmer-than-usual weather is causing allergy symptoms to flare up earlier than normal or even get worse for some allergy sufferers in Canada.
In addition to a general warming that scientists have attributed to climate change – last year was the planet's hottest on record – the impact of El Nino meant this winter was warmer than most in much of Canada.
Canadians say they're noticing the change.
'All year'
Gale Rettie, 71, says she has suffered with environmental allergies since she was a teenager but it has gotten worse.
"It seems the older I get the more I am affected," said Rettie of Dryden, Ont., in an email to CTVNews.ca. "For the past two months my symptoms have been almost constant -- runny nose, itchy eyes, cough from post nasal drip, achy facial bones. I have found it gets worse with the milder winter temperatures we have been having and gets better with the drop in temperatures and snow storms."
When a specialist tested her at age 19 and in her 60s, Rettie said, she learned both times that her allergies were related to trees, pollen and moulds.
Although allergy injections in her early 20s didn't help much, she said, she had surgery in 2018 to open blocked sinuses, which made breathing much easier.
"Now I have a (prescription) for Reactine, which gives short term relief," she said. "It is something you just learn to live with."
Scott Wagner, 51, from Yarmouth, N.S., says he, too, has seen his allergy symptoms get worse in the last 10 years.
"I find for sure that the mild winters have changed my allergies a lot," Wagner said in an email to CTVNews.ca, noting that he experiences allergy symptoms year-round now. "The season is definitely not like it was 10 years ago."
Wagner says he used to stop taking pills for his allergies from mid-November to mid-March.
"But now I have to take them all year since mild days through the winter that never happened before triggers my allergies."
CTVNews.ca has not independently verified the emailed responses. Rettie and Wagner are among environmental allergy sufferers in Canada who are experiencing exacerbated symptoms because of what an allergy expert notes are higher amounts of pollen in the air as a result of warmer or drier weather.
Causes of allergies
Dr. Mariam Hanna, a pediatric allergist, clinical immunologist and associate professor with McMaster University in Hamilton, Ont., says pollens contain a protein that irritates allergy sufferers. Dry and warm wind can help them travel for thousands of kilometres. Pollens are fertilizing fine powder from certain plants such as trees, grass and weeds.
"People that are allergic to pollen, when they breathe that in, when it goes inside their nose or goes inside their eyes, it will cause those typical allergy symptoms," Hanna said in a video interview with CTVNews.ca. "So when it's warm and dry, it's kind of the perfect environment for pollen to travel further and stay up in the air for longer and that will cause people more symptoms."
She said pollen counts have been increasing each year.
"Year-over-year, when we compare the last five years, every year, we're adding a couple extra days, or now an extra week or two to our (allergy) season when we can detect pollens in the air," Hanna said. "As long as it stays warm and dry, those pollens can be in the air. When it becomes more damp or cools off, those plants die down or they start to hibernate for the winter and the air no longer carries those pollen seeds.
"So if this mild winter that we just went through is any indicator of a warm summer ahead, that's concerning for a longer pollen season with higher counts than what we've seen in the past."
Environmental moulds also cause problems for allergy sufferers, she added. In these cases, moulds' spores travel like pollen in the air and cause allergic symptoms.
Hanna says environmental moulds grow when plant matter decays, water sits for a period of time or leaves decay.
"So typically speaking we have moulds that grow outside, and that's very, very normal … Their spores will also go up in the air in unison with different pollens going up. There will be different moulds that go up at different times throughout the year."
Moulds can affect people in the spring, during warm weather in the summer and in the fall when plants start to die and it's still warm and humid, she added.
Impact of climate change
At least about 20 per cent of Canadians have some degree of environmental allergies, said Hanna, "and certainly with our seasons being longer and counts being higher, those that have symptoms is only increasing."
Climate change is a factor in exacerbating allergy symptoms because of the warmer weather that promotes the spread of pollen, Hanna says.
"This is an unseasonably warmer winter that we've just gone through, but I would say the pattern for year over year of what we have experienced … has been that our pollen seasons have been longer, the pollen counts have been higher, kind of regardless of whether it's El Nino or not."
Seasonal allergy symptoms
Hanna says allergy symptoms include itchy watery eyes, runny nose, nasal congestion, coughing and sneezing.
Health Canada adds that some may experience wheezing, flushed face, shortness of breath and a peeling rash that looks like eczema.
How to tell if it's a cold, flu or allergies
Depending on your allergy symptoms, it can be difficult to determine if you have a cold, flu or allergies, Hanna said.
"Sometimes the pattern of symptoms, how long they last and how they respond to medications, seeing an allergist for testing will help to confirm that."
When is spring allergy season?
It's hard to predict when spring allergy season begins and ends, Hanna says.
"It's so different every single year. March is definitely an earlier time that we're seeing it," she said. "Typically by April, we've definitely started in our birch pollen season. Our tree pollens have started to fully pollinate at that time and stay elevated at that time."
Less than a week into March, counts for some tree pollens have started to be detected because of "unseasonably warm, dry air," Hanna noted.
She said pollen counts are the amount of the protein in pollen that is in the air that is measured in a certain volume. Pollen counters, or devices that measure pollen protein, are found throughout the country.
"But the pollen counts are starting to be detected even right now. This may be a blip for a couple of days but unless it cools off, this is the beginning of pollen season at a much earlier time than what we usually see at this time."
She said more people are "symptomatic and sensitized" to spring pollens.
The allergy seasons include tree pollen season during the spring into early summer, grass pollen season from late spring into summer and ragweed season during fall.
During winter, most Canadians don't see many allergy symptoms because of the cold, "but if global warming persists, or if our warm weather persists, we may not get much of relief if it ends up being warm all year long," Hanna said.
Meanwhile, mould season occurs from spring until fall and some patients have year-round allergies, she added.
People in different areas of the country won't experience symptoms at the same time because pollens will peak at different times, Hanna said.
"So our typical trees that pollinate at this time of year (in parts of Ontario) may be offset by even several weeks or a month than our counterparts (out) west where it's still a little bit cooler there … so pollen counts may not go up as quickly and steadily as in Ontario."
It even varies depending on where in your province you're located.
Some areas of Ontario will experience different pollen counts, Hanna said. Windsor and London, for instance, will have "significantly different" pollen counts than around Hamilton, Hanna said, despite the cities only being a few hours' drive apart.
"The exact timing of the pollen counts will be subtly different from one province to the next and even from one region within that province to the next."
Tips on coping with allergies
Hanna recommends the following tips for dealing with allergies:
- Keep windows closed if you know pollen counts are high;
- Take a quick shower after you come back home to remove any pollens stuck on you;
- Wear sunglasses to help protect your eyes; and
- Immunotherapy can help patients retrain their bodies by working with an allergist so they become more tolerant to pollens and have fewer symptoms.
"Some patients will need medications like over the counter antihistamines or speaking with their doctor about the right types of medications to help with symptom control," she said.
