A Q&A with Dr. Susan Waserman, Canada’s top asthma and allergy expert.
Fall is one of the worst times of the year for allergy and asthma sufferers as we head back indoors after the summer. That’s because some of the worst triggers for allergies and asthma can be found inside our classrooms, homes, even our mattresses. Dr. Susan Waserman, chair of the Asthma Society of Canada’s Medical and Scientific Committee and a leading allergist at McMaster University in Hamilton, Ont., calls this time of year the September Peak.
Let’s start with the basics. What causes allergies?
Allergies are caused by an antibody called IGE, found on cells called mast cells. This antibody and these cells are the cornerstone of allergic reactions like sneezing, itchy eyes and runny nose. Not everybody becomes allergic, though—you need exposure, as well a genetic makeup that causes you to form this antibody to certain allergens and the environment.
What about asthma?
Allergy is one of the causes of asthma, but not all asthma is allergic. Asthma can be triggered by viral infection, occupational exposure, exercise—it’s complex. But allergies and asthma really are related: 80 percent of asthmatics will have allergic rhinitis, and people with allergic rhinitis are two to three times more likely to have asthma.
Why is fall such a big allergy and asthma season?
Ragweed peaks around Labour Day, but viral infection is even more important in triggering asthma. It is rhinovirus season starting in September. People are back in close quarters, viral infection and transmission are pretty high, and a lot of parents use the summer to give their kids a drug holiday. Kids enter school and they’re probably not as well controlled as they are ordinarily, and things can flare up.
What are some of the triggers of asthma and allergies in the home?
House dust mites are a big one. Pet dander for sure. Cockroaches are a problem, especially in the inner city, and moulds. Those would have to be the top allergens in the home.
They almost look like a crab, or spider. They’re quite unsightly. Luckily, they’re microscopic. They live primarily in mattresses and what people are allergic to is their fecal matter, specifically a certain enzyme called a protease found in it. People will form IGE to that. They’re extremely common and they live where their food source is, namely upholstered material, but mainly in mattresses because they feed off human dander and human skin scales.
What can people do to control allergies and asthma at home?
If you’re pet-allergic, you shouldn’t have a pet in the home. For things like pollens, keep windows closed in the home and in the car, and try to confine exercise to times when pollen counts aren’t high—if that’s at all practical. If you’re outside and pollen gets on your clothes, take them off before you come into the house. Vacuums with HEPA filters can be part of a comprehensive allergen reduction program by decreasing exposure to allergens like dust mites. Ultimately, though, individuals with allergies and asthma need proper diagnosis and treatment.
What can parents do to make sure that kids with allergies and asthma are OK at school?
It’s hard to control the environment in a school. People are going to come in wearing pet dander or whatever on their clothes, but we do have good medications. I think the best way to handle the September Peak, as we call it, is to be properly medicated and keep up with your physician. A week or two before school, I tell all my asthmatics, ‘Get ready. Start your medications again if you’ve stopped, and pay attention to symptoms of control: poor exercise tolerance, coughing at night, wheezing, fatigue.’
Any further advice?
Take the guesswork out of it. See an allergist if you think allergy is a factor. I think the message is: don’t suffer in silence. There is a lot of good stuff out there in terms of treatment.