Allergy-Proof Bedding Not Enough
But Dust Mite-Resistant Covers Can Still Help Allergy, Asthma
Another expert, who wrote an accompanying Journal editorial to the two studies, tells WebMD that while both were well-conducted trials by respected researchers, they had "conceptual errors" in execution.
For instance, because the researchers didn't know which patients were specifically allergic to dust mites -- as opposed to other allergy-triggers -- they can't really measure the exact role of the coverings, says Thomas A.E. Platts-Mills, MD, PhD, of the University of Virginia Asthma and Allergic Disease Center in Charlottesville.
"And in one study, they recommended that both groups of patients regularly wash their bedding," he says. "If you're washing bedding regularly, covering the mattress as well only has a modest effect in reducing allergen exposure.
"It's as if the researchers handed out different mattress covers to people who weren't doing a lot of the other things that they should to prevent or control their condition," Platts-Mills tells WebMD. "That's almost like saying, 'If you are supposed to use an inhaler twice a day to control asthma, will it work as well if you use it only once?' The answer seems obvious."