Allergies start in your home

Originally published in The Ottawa Citizen April 1, 2003
Original Title: Mighty Mites!

Allergies affect millions of people in North America. Although medications help to control asthma, allergic rhinitis and eczema, control of our local living environment is essential. Prevention can reduce or eliminate the need for medications.

Our homes are hosts to millions of creatures and organisms that produce waste material. This material (allergens) is the source of allergy-based misery. Without proper identification of these allergens, it is difficult to provide long-lasting relief.

Over years of exposure to allergens, the immune system tends to overreact and produce an allergic response. This process is called sensitization. Exposure to various household allergens can lead to dry skin rashes or eczema, asthma, stuffy nose (rhinitis) and watery eyes (conjunctivitis). Allergy testing helps determine those allergens responsible for these conditions.

Dust mites infest our homes. These critters, related to the spider family, are 0.3 millimeters in size and love to eat our dead flaking skin. They live in dusty places with an ambient temperature of 21°C and relative humidity of 70 per cent. The mite’s fecal pellets cause the allergy. These relatively large pellets (from a microscopic standpoint) only remain airborne for several minutes once disturbed.

The areas of your home prone to these guys are carpets, pillows, mattresses, drapes, stuffed animals, clothing and upholstered furniture. Since these items are frequently used, the pellets will fly.

A pet’s skin, saliva, urine and feces provide a rich allergen source. Cat dander is the worst offender. It can remain airborne for some time, enough to spread throughout the house. Dander levels can remain in the house an average of 20 weeks after the cat has moved on. Further, it is impossible to remove cat dander from bedding, mattresses, carpets and furniture.

Cockroach allergens, found in household dust, have a strong link to asthma according to some studies. Roaches tend to congregate in dark areas of the kitchen feeding off crumbs and scraps of food falling into the nooks and crannies.

Indoor and outdoor fungi or moulds, Cladosporium, Penicillium, Aspergillus, Aternaria and Ganoderma produce spores that can cause asthma. The Weather Network ( reports the summertime spore counts.

Environmental control measures are essential to prevent or minimize allergic reactions. Indeed, identification and subsequent eradication of the offending allergens early in a child’s life can reduce the risk of asthma. Medications and allergy shots should be part of the treatment if necessary and not the sole therapy.

If you smoke in the house, stop. Smoke permeates throughout the house even if you lock yourself in a room. Children are most susceptible to the affects of second hand smoke increasing their risk of lung disease, asthma and ear infections. Smoking during pregnancy increases a child’s risk of asthma twofold and can cause a three to five per cent reduction in lung function.

Dust mite control will lead to a cleaner less irritating environment:

  • Pillows and mattresses should have a vinyl or semipermaeable cover. This can reduce the population 100 to 1000 fold
  • Wash all sheets, pillowcases and comforters every one to two weeks in hot water (54°C or 130°F).
  • Dry cleaning and tumble drying at 54°C will kill the mites
  • Remove bedroom carpeting and any that overlies concrete. Regular vacuuming does not remove the dust mites.
  • Wet mopping all vinyl and hardwood floors weekly can remove 90 per cent of the allergen.
  • Reduce indoor humidity to 50 per cent or less.
  • Ensure that your child’ stuffed toys are washable. Throw out those that are not.
  • Chemical agents that kill mites are not effective.
  • Since pet allergy sufferers rarely remove their pet from the home, the next best choice is to keep them out of the bedroom and off the carpets and upholstered furniture.

Avoidance of pets during infancy is not a recommendation. There is some evidence to suggest exposure at this age can reduce the risk of asthma and allergies.

Any way you can kill cockroaches is acceptable. Share your method with others. Clean up any food spills and keep the kitchen spotless.

Indoor moulds need moisture to grow. Check for any water leaks or damp areas. Use a dehumidifier in the basement to reduce the humidity level to less than 50 per cent.

These measures are relatively easy and economical to institute. Most people suffering from asthma should benefit from allergy testing. These straightforward steps can reduce exposure to substances that allow you to smell the roses – provided you are not allergic.

© Dr. Barry Dworkin 2003

Send a Comment