Dust, mold, grass, dander… you name it, I’m allergic to it. So I was dismayed recently when I read articles in the media proclaiming the futility of commonly used methods for allergy-proofing a home. These stories were based on an analysis of about 50 studies that concluded that home modification does not reduce allergy symptoms.

Does this mean that allergy sufferers should give up on trying to minimize allergic triggers that we’re exposed to at home? Absolutely not, said Mark S. Dykewicz, MD, chief of allergy and immunology at Wake Forest University School of Medicine. He told me about several problems with the analysis and with the media coverage of it. Specifically…

  • This analysis looked only at dust mite allergy and only at relief from asthma symptoms. The authors suggested that commonly used measures to reduce dust mites may not lower dust mite levels enough to make a difference. But in the media, the message that often came through was applied far more broadly — as if the study had debunked all avoidance methods for all allergens and all types of symptoms. The facts do not support this conclusion.
  • The studies that were analyzed generally did not take “participant compliance” into consideration. Dr. Dykewicz said, “People often make mistakes in implementing allergy-avoidance strategies — so a lack of effectiveness may not stem from faulty strategies, but partly from faulty execution.”
  • Many mite-sensitive asthmatics also are allergic to other things, and the combined effects of all these allergens can trigger significant symptoms. That’s why a focus on reducing exposure to just one allergen is too limited. When allergy testing has been used to identify all of a particular patient’s major allergens (for instance, dust plus dog dander plus molds) and a plan is implemented that simultaneously reduces exposure to them, asthma symptoms are reduced.

WHAT REALLY WORKS

Instead of giving up on allergy-proofing, Dr. Dykewicz suggested doing a more thorough job — by identifying all your major allergens and taking measures to reduce exposure to each. This can make a difference if you do it right…

Wash clothing and bedding at 130°F or hotter to kill dust mites and neutralize pollen and pet dander. Hot water breaks down proteins and other substances that cause allergies.

Common mistake: Just pushing the “hot” button on your washing machine without first adjusting the thermostat on your water heater to produce water that’s really hot enough.

Also important: Clothing you wore when you were exposed to allergens (for instance, while hiking in the woods or visiting a household with a cat) picks up those allergens — so as soon as you get home, take off those clothes and wash them before wearing them again. Also remove shoes when you enter your house and leave them at the door.

Shower and shampoo as soon as possible after working in the yard or spending recreation time outdoors.

Common mistake: Waiting until morning to shower — which leaves yesterday’s allergens all over your bed linens.

Use the right mattress and pillow encasements. Only covers made out of very tightly woven or plastic material prevent dust mites from penetrating and colonizing, so choose woven encasements with labels that guaranty a “mean pore size” of no more than six to 10 microns. (Check product packaging or manufacturer’s Web site.)

Common mistake: Buying cheap “allergy-proof” products made from pressed fibers or loosely woven materials that do not meet these standards.

Also: Encase pillows of all types. Surprisingly, an uncovered polyester fiberfill pillow can be a more fertile breeding ground for dust mites than a feather or down pillow.

Reduce indoor humidity by using air-conditioning and dehumidifiers and by venting kitchens and bathrooms. Humidity promotes growth of some allergens, such as dust mites and mold.

Common mistake: Using humidifiers, which can increase allergen levels and symptoms.

Keep windows closed if you are sensitive to molds and dust.

Common mistake: Wrongly believing that an open window brings in a “nice, fresh breeze.” In fact, outside air can have high concentrations of molds (not to mention pollens), especially on dry, breezy days. In winter, if there has been an extended period of freezing in your area, outside air contains few allergens — but opening windows to let in a breeze could stir up indoor dust mites on fabrics and carpets, making them airborne.

Filter your air. A room air purifier with a high-efficiency particulate air (HEPA) filter can reduce airborne allergens, such as cat dander.

Common mistake: Using ozone air purifiers, which are much less effective at removing indoor air contaminants — and some models can generate ozone at potentially harmful levels. With central heating and air-conditioning systems, follow manufacturers’ recommendations to change filters every three to six months to allow for efficient filtering.

Choose the best vacuum. Vacuums with built-in HEPA filters or vacuums fitted with HEPA bags or double-thickness bags are better than regular vacuums at keeping swept-up allergens from escaping back into the room air.

Common mistake: Buying a bagless vacuum, which tends to allow more allergens to escape and is too difficult to empty without releasing the collected allergens.

Remove carpeting. Leave floors bare or use small, washable area rugs. Carpets placed directly over concrete, as in basements or on the ground floor of houses built on concrete slabs, can become chronically moist and provide breeding grounds for dust mites and mold.

Common mistakes: Assuming that wall-to-wall carpeting is OK as long as it is synthetic instead of wool (though, in fact, any type of carpet traps allergens)… or relying on carpet sprays and powders that purport to reduce allergens (but actually produce minimal results).

The bottom line? Yes, it takes a lot of effort to properly allergy-proof your home — but it’s worth it.