The bulk of the average home’s dust mite population is in the bed. As we lay in our beds, we shed millions of dead skin cells, which give dust mites an unlimited food source. As they multiply and release their fecal matter into the mattress, an allergen nightmare is born. These fecal particles and our own skin and hair cells are what cause the allergies we experience. The only logical way to separate us from this dust mite breeding ground is to create some kind of barrier. This is why allergists usually start with recommending the purchase of allergy covers.
Hypoallergenic dust mites covers for mattresses, box springs, and pillows create impermeable barriers between sleeping allergy patients and dust mites and their allergens. They literally let you breathe easier. In fact, a Danish study revealed that simply encasing mattresses and pillows of child asthma patients substantially relieved their symptoms. After one year the children were using half as much of their steroid inhalers and showing better peak-flow readings in exhalation tests.
The most important attribute of any hypoallergenic cover is “pore size.” That term refers to the spaces between threads in fabric. Keep the following in mind:
Dust mites themselves measure 200-300 microns (a micron = 1/1000 millimeter).
Dust mite fecal pellets (the major allergen source) are 4-20 microns.
Fecal pellets can crumble even smaller.
Encasements are covers that enclose a mattress, box springs, or pillow completely. Regular “fitted” mattress pads or mattress covers do not do this, and therefore offer no protection against any kind of allergen, let alone dust mites. Typical encasements are zippered. Some experts even recommend taping over the zippers to insure complete closure.
Consider applying encasements to a new set of mattress and box springs, so as not to simply trap existing dust mite populations (and their feces) inside the current mattress. Trapped dust mites can subsist for months, perhaps years, on the shed skin fragments already in the old mattress or box springs. The same suggestion applies to pillows.
There may be some trade-off between a mattress encasement that is comfortable to sleep on and one that is most effective at protecting a person from allergens. That divide is shrinking all the time though as new products enter the marketplace. You may find this Allergy Bedding Buyer’s Guide helpful in reaching a decision on which products best meet your needs.
Some types of encasements can be laundered, while others are meant to be dusted regularly with a damp cloth. Pay careful attention to the labels and instructions that come with your purchase. The better you care for them, the more effective and longer lasting those products will be.