Originally titled "Winter Allergies," from the February 2008 issue of Canadian Living Magazine, on newsstands or click here to purchase online.

Since people spend more time indoors during the winter months, they're exposed for longer periods of time to housebound allergens like dust mites and pet dander. When a susceptible person breathes in or touches these normally harmless substances, the body mounts an allergic reaction that typically leads to sneezing, stuffy nose and watery eyes, says Dr. Gordon Sussman, a professor of medicine and division director of clinical immunology and allergy at the University of Toronto. Here's what you need to know about "winter" allergies.

1. Dander from your pet is one of the worst triggers of winter allergies
Dander from the family pet – dogs, cats, rabbits and even some birds – can trigger an allergic reaction, as can dust mites that live in bedding, furniture, curtains and carpets, and moulds that flourish in damp places such as potted plants, basements and bathrooms. Animal dander, dust mites and mould can also trigger an asthma attack (asthma affects the airways, whereas allergies affect the nasal passages).

2. The main troublemaker in winter allergies is a chemical called histamine
When susceptible people are exposed to allergens like pet dander, moulds or dust mites, their body's mast cells release histamine, which triggers a cascade of biological events that lead to sneezing, itchy watery eyes, runny nose and nasal congestion. People with winter allergies are also prone to sinusitis (infected or inflamed sinuses), which causes facial and ear pain and sinus headaches.

3. Antihistamines help relieve some of these symptoms
Over-the-counter products (for example, non-sedating Aerius and Allegra or the more sedating antihistamines such as Benadryl, Chlor-Tripolon and Reactine) help relieve the histamine-induced itchiness. Over-the-counter eye drops, such as Opticrom, may relieve eye symptoms. For relief of nasal congestion, a topical nasal steroid (such as Rhinocort, Nasacort, Nasonex, Flonase) targets nasal congestion directly; more potent nasal sprays are available by prescription. People whose allergies are triggered by animal dander or dust mites should also talk to their doctor about getting allergy shots. This "immunotherapy" can induce excellent protection against certain allergens, although it can take two to three years to see results.

4. For optimal control of winter allergy symptoms, minimize your exposure
If you can't part with your family's pet, try to keep Rover outdoors as much as possible; when he's inside, keep him out of your bedroom. To minimize dust mite exposure, wash sheets, pillow cases and all other bedding in hot water once a week. As well, enclose your mattress, box spring and pillows in dust-mite-proof covers (search the Internet if you can't find these covers at your local department store). If you're allergic to dust mites or moulds, toss out the carpets in your home and keep the underlying wood, tile or linoleum floors as clean as possible. Dehumidifiers or air conditioners are good for humidity control; set them at 50 per cent humidity or less to prevent dust mite and mould growth.

Indoor air
Air in your home and office might be setting off your allergies, but there is always a way to ensure it stays as clean as possible. Here are tips for maintaining good indoor air quality.
• Avoid smoking indoors.
• Don't leave your car idling in the garage; exhaust fumes could find their way into the house.
• Paint, sand and perform other pollutant-causing activities outside.
• Open windows and doors to increase air circulation.
• Turn on exhaust fans in the kitchen and bathroom.
• Consider installing mechanical ventilation systems, which bring outdoor air inside. Some of these systems include heat recovery ventilators.
• Monitor the humidity in your home – there should be no more than 50 per cent humidity in summer and 30 per cent in winter.
• Regularly check for and repair water damage from leaks that might lead to mould formation.
• Place electronic air cleaners, ion generators and/or mechanical filters throughout the house to trap particles that may trigger allergies.
- by Lyndsie Bourgon

Thinking of adding a second pet to the family? Click here to read some tips from the experts.