The last days of summer and early days of fall bring shorter days, new school and work routines, and for many Canadians, the sneezing, runny nose, and watery eyes of allergic rhinitis. There are many possible culprits, including tree pollen, grasses, mould, pet dander or ragweed. These triggers are prolific – a single ragweed plant, for instance, can produce a billion grains of pollen in a season1. And environmental factors like climate change and pollution, together with our changing lifestyle patterns, are contributing to more people feeling the effects of ragweed and other seasonal pollens than ever before.
The phenomenon is not unique to Canada - one global study found airborne allergens like pollen had increased an average of 96.3 per cent across 17 countries from 1998 – 2016. Though Canada landed on the lower end of the average with a 51.3 per cent increase2, it’s clear that the air of the Great White North is getting increasingly clouded with allergy triggering pollens. And while there is no ‘cure’ for allergic rhinitis, the good news is that there are well-established treatment options for symptom relief.
State of the Nation: Allergic Rhinitis in Canada
Allergic rhinitis is a chronic respiratory disorder that has been estimated to affect between 10 to 30 per cent of the global population across all age groups and approximately 20 to 25 per cent of Canadians3. Allergic rhinitis is an inflammatory disorder that occurs when the body has an abnormal reaction to various particles in the environment, called allergens. Allergens can include pollen, grasses, trees, dust or pet dander, and others that cause inflammation of the mucous membranes of the upper respiratory tract. Allergic rhinitis typically causes symptoms such as sneezing, runny and itchy nose, itchy and watery eyes, nasal congestion, or even the worsening of other conditions like asthma.
The quest for symptomatic relief is something Joseph Chan, Regulatory Affairs Manager for Bayer Consumer Health and a practicing pharmacist in the Greater Toronto Area, sees often at this and other peak times of year.
“Allergic rhinitis is a very frequent interaction in the pharmacy,” says Mr. Chan, who experiences mild seasonal allergies himself. “You could be feeling constant bother, and if it’s more severe, you may not be able to function as well. It’s about quality of life.”
Dr. Christopher Sans, PhD, Medical Advisor at Bayer Consumer Health, agrees that seasonal allergies are more than just a temporary annoyance.
“Allergic rhinitis is highly prevalent globally, and can have a significant impact on quality of life, work and school productivity, ability to sleep, and other medical conditions,” Dr. Sans says.
Canadians sensitive to outdoor, or seasonal, allergens can potentially experience more than one round of symptoms, as tree pollen, grass pollen and ragweed pollen all impact different provinces at different times. Only the coldest winter months offer a reprieve from most drifting pollen allergens. What’s more, within each ‘season,’ there are daily or even hourly fluctuations in the pollen count.3
Behind the Challenge
Though the rising prevalence of allergic rhinitis is not attributed to a lone cause, one major driver is climate change, which is caused primarily by increasing levels of carbon dioxide CO2and other greenhouse gases in the atmosphere4.
Rising temperatures triggered by climate change are prompting earlier and longer seasons for plants like ragweed5 - in Winnipeg, Manitoba, the growth season may have increased by 25 days6 between 1995 and 2015. Higher levels of carbon dioxide in the atmosphere mean plants are also producing more pollen – one study projects a 60 to 100 per cent increase in pollen production by 2085 if fossil fuel production continues unabated.7
In addition to the impact of rising temperatures there is a major shift to where we are living. Fewer than one in five Canadians live in a rural setting today8 – a marked shift from Canada’s early rural roots. Urban density means more air pollution, which has been shown to increase the allergenic properties of pollen9. City planners have also tended to favour planting male trees because they don’t produce fruit or seed pods, but they do produce lots of pollen. With fewer female trees around to trap that pollen, city streets are pristine but those with allergic rhinitis are stuck breathing pollen-clogged air10.
It’s also about how we’re living, says Dr. Sans.
“Rising trends for allergies in urban areas may in part be explained by more time spent indoors and our decreased exposure to natural and abundant allergen sources, leading to lower tolerance,” he explains. “In the end, while there is likely not to be one answer as to why we are seeing an increase in the prevalence of allergic rhinitis, what is clear is that experts agree it is increasing at a significant rate.”
Symptoms of Our Times
During the global pandemic, it can be confusing to figure out whether symptoms are due to allergies, a cold, flu, asthma or the COVID-19 virus. The Allergy and Asthma Foundation of America has developed a chart12 that outlines the typical
symptoms for each. Always check with a health care professional
if you are
unsure or have any questions.
The good news for those living with allergic rhinitis, says Dr. Sans, is that there is a well-established, globally recognized step-wise path for managing symptoms.
“The treatment goal for allergic rhinitis is to relieve symptoms, and the first step is allergen avoidance,” he says. “Then you have newer generation antihistamines, which are a cornerstone of treatment, and you may or may not include a nasal spray like a sterile nasal saline solution or a decongestant. And then there are intranasal corticosteroids, which are becoming more available over the counter, additional over-the-counter and prescription treatments, as well as allergen immunotherapy, which is reserved for the most severe patients.”
While self-care is important part of getting relief, he emphasizes that people who are unsure if they have allergic rhinitis should seek advice from a healthcare professional first. Joseph Chan, who fields questions about allergic rhinitis frequently as a pharmacist, agrees, pointing out the importance of the right diagnosis and the trial and error it may take to find what works best.
“A differential diagnosis is required first,” he says. “Then people generally have to try things out to see what works for them. Finding the right regimen can be more of an art than a science.”
Art or science, symptom relief will be the goal for millions of Canadians looking ahead to a ragweed season predicted to be tough – and expected to last all the way to the first frost.
Canadian expert talks allergic rhinitis in video series
Want to know more about allergic rhinitis? Check out the Special Allergy Series on Canadian Health and Family, featuring Dr. Paul Keith, Allergist and Clinical Immunologist at McMaster University.
Take Charge of Your Seasonal Allergies11
Allergic rhinitis got you down? Fight back with these tips.
Prepare – get proactive and make sure you have the allergy medication that works for you, such as an antihistamine, on hand when your symptoms start.
Scrub in – rinse away the allergens on your body by washing your hands and face when you come inside and showering before bed.
Tidy up – Keeping a clean house also helps, so get out the mop and vacuum more frequently, and launder your bedding often. Also, remember to remove your shoes when you come inside to avoid tracking pollen through the house.
Check out – The pollen forecast can change daily or even hourly. Check it before you go outside so you know what to expect.
1 American Academy of Allergy, Asthma and Immunology. https://www.aaaai.org/conditions-and-treatments/library/allergy-library/ragweed. Accessed August 6, 2020.
2 Bayer Magazine. The Pollen Problem. https://www.magazine.bayer.com/en/the-pollen-problem.aspx. Accessed August 6, 2020.
3 Kosisky, S. E. et al. Fluctuations in airborne grass pollen levels as determined in three-hour intervals during a 24-hour period. The Journal of Allergy and Clinical Immunology. Feb. 1, 2010. Accessed August 18, 2020.
4 David Suzuki Foundation. Accessed August 6, 2020.
5 Ziska, Lewis H. et al. Temperature-related changes in airborne allergenic pollen abundance and seasonality across the northern hemisphere: a retrospective data analysis. The Lancet Planetary Health, Volume 3, Issue 3, March 2019. Accessed on Science Direct, August 6, 2020.
6 Environmental Protection Agency. Accessed August 6, 2020.
7 Ziska, Lewis and Caulfield Francis. Rising CO2 and pollen production of common ragweed (Ambrosia artemisiifolia L.), a known allergy-inducing species: implications for public health. Functional Plant Biology 27(10). Accessed on ResearchGate, August 6, 2020.
8 Statistics Canada. Canadian Megatrends: Canada Goes Urban. 2015. Accessed August 6, 2020.
9 Sénéchal, Hélène et al. A Review of the Effects of Major Atmospheric Pollutants on Pollen Grains, Pollen Content, and Allergenicity. The Scientific World Journal, Volume 2015. Accessed August 6, 2020.
10 Ogren, Thomas Leo. Botanical sexism cultivates home-grown allergies. Scientific American. April 2015. Accessed August 6, 2020.
11 Adapted from Bayer Marketing piece - Claritin_Amazon_3&4_AWB. 2019 Allergy U&A. (courtesy L. Baumgartner).
12 Allergy and Asthma Foundation of America. https://www.aafa.org/media/2631/respiratory-illness-symptoms-chart-coronavirus-flu-cold-allergies.png Accessed August 6, 2020.