Dust Mites Can't Be Beat?

A study in Denmark found dust mite products don't work, yet doctors disagree.

ByABC News
January 8, 2009, 1:18 AM

April 16, 2008— -- For asthma and allergy sufferers who hate dust mites, a new scientific analysis from Denmark claims there may be little you can do.

The researchers in Denmark analyzed 54 previous dust mite studies that included a total of 3,000 asthma sufferers. They found that none of the available anti-dust mite products, such as special mattress covers or chemicals, significantly improved the patients' symptoms.

The researchers report that even if the products kill off some dust mites, the allergens they leave behind still cause difficulties. And despite a thorough scrubbing of sheets, there still is enough dust left around the home to make people sick.

But many allergy experts in the U.S. disagree and question the report's assertion that asthmatics should ditch their hypoallergenic products and cleaners altogether.

Currently, 22 million Americans suffer from asthma, and more than 6 million of them are children. For someone suffering from shortness of breath, dust mites that trigger allergic reactions only make breathing problems worse.

In fact, doctors estimate that 70 percent of asthmatic patients are sensitive to dust mites.

"Asthma is a highly complex disease," said Dr. Miles Weinberger, director of the Asthma and Allergy Center and the University of Iowa Children's Hospital, who noted a "high degree of variability in the studies" analyzed by the Denmark researchers.

Many outside factors can change the effectiveness of an anti-dust mite product such as the local climate, humidity, other products in the room and even the sensitivity of the particular person with asthma.

"Dust mites like high humidity, which results in greater exposure and probably greater clinical importance in the U.S. Southeast and the UK than in northern climates, where central heating causes homes to be bone-dry in the winter," said Weinberger.

Apart from location, other allergies confound the difficulty to see if dust mites are the problem, or if products to fight dust mites are working.