Dust mite allergies not solved by special mattress covers, study suggests

Expensive mattress covers may not help with dust mite allergies, according to recent U.S. clinical trials.

Almost 40 percent of people worldwide suffer from allergies, and dust mites are believed to be one of the most common causes. To relieve symptoms, doctors advise allergy sufferers to buy expensive mattress and pillow covers even though there's no proof they work.

"Based on this analysis which combines data from many different studies, there doesn't seem to be any benefit to using dust mite covers to prevent allergic disease or to prevent symptoms," lead author Whitney Arroyave, from the Tulane University School of Public Health and Tropical Medicine in New Orleans, told Reuters Health.

The results from these 24 clinical trials, published in the journal Annals of Allergy, Asthma and Immunology, found that mattress covers reduced house mite dust exposure by 20 percent. However, this reduced impact was not statistically significant in terms of house dust mite sensitization, or effective on symptoms such as wheezing, asthma, runny nose or dermatitis.

Arroyave isn't sure why the mattress covers don't work, but notes it could be a result of several factors, like the possibility they don't lower mite levels enough to improve symptoms or that beds aren't the main source of dust mite exposure.

"Or maybe it's not the dust mite at all - maybe they're not causing the problems," she added.

Allergist Dr. Samuel Friedlander explained another reason the mattress didn't prove to be successful.

"If you do a single thing like dust mite covers, but you're still exposed to dust from other sources in your house or work, or if you have other allergies like pets or pollens, then of course a single measure like dust mite covers is not going to be effective," he said.

Mattress covers are over $100 a pop, but this expensive treatment method is only one option for relieving allergies.

"So the take home message for me is that dust mite covers are still very important, but they should be part of a comprehensive treatment plan," he said.