But one of the most effective ways to reduce the mite population in your bed is simply to wash bedding weekly in hot water of at least 140 degrees. Battling dust mites outside the bedroom is harder. But doctors say the filters fill up quickly and have little impact on dust mites, which generally aren't airborne. Recently, S.C. Johnson introduced, then withdrew, its AllerCare carpet powders and sprays that contained low levels of a pesticide used to kill dust mites. The problem, a company spokeswoman said, didn't appear to be with the active ingredient, benzyl benzoate, but with the amount of fragrance added, which caused reactions in some asthma sufferers.
Allergists are wary of the long-term effects of exposure to pesticide.
The best way to get rid of dust mites in your carpet is to get rid of the carpet, says Dr. Lanny Rosenwasser, head of allergy and clinical immunology at the National Jewish Medical and Research Center in Denver. They've discovered that one low-level treatment eliminates dust mites for a year. No products are yet on sale, but some manufacturers are working on permethrin-based products, including sprays and pretreated mattresses and carpets, says Emmett Glass, an OSU research associate leading the university's ongoing Dust Mite Management Study. Doctors say they are glad allergy marketing is going mainstream. The hope is that increased awareness will encourage allergy and asthma suffers to change their environment rather than depend on medicine.