Breath of Fresh Air: Feature Articles

Chapter 12: Making the Home Safe for Asthma: Dust Mites

For persons allergic to hidden molecules in the air ("allergens"), the world around us can seem a hostile place. In the home we may be "attacked" by dust, mold, animal danders, or cockroach debris; outside there are pollens and mold spores and high levels of air pollution; at work or in stores there may be second-hand cigarette smoke, chemicals or fumes in the air, or exposure to latex rubber. Sometimes it seems that our allergies make us vulnerable to "the whole world."

What can be done to protect ourselves from breathing in these allergens on a daily basis and thereby prevent worsening of the allergic inflammation of our airways? And how can we avoid the occasional intense exposure that can trigger a severe worsening of symptoms – an asthmatic attack? In fact, a lot can be done. The more that scientists have learned about the allergens in the air that we breathe, the better we have become at developing ways to reduce our exposures to them. Practical actions in the home or workplace can help to control our asthma, even before taking a single tablet or inhaler spray of antiasthmatic medication.

In this article we will focus on changes that can be made in the home, especially in the bedroom, to minimize exposure to the dust mite.

Practical actions in the home or workplace can help to control asthma — without any medications.

Not everyone with asthma is allergic to dust mites. Before making changes in your home to reduce your exposure to dust mites, it is a good idea to determine whether you have dust mite allergy or not. Sometimes you can tell simply from your own experience. If every time you dust or vacuum you experience worsening of your asthma, it is likely that you are in fact allergic to the droppings of the dust mite that accumulate in house dust. If your experience has not been so clearcut, you can further sort out your personal allergic tendencies with allergy skin or blood testing. Your doctor can advise you as to the best method of testing.

House dust mites are microscopic creatures that thrive in warm, moist environments and feed on human scale (sloughed skin) and on animal danders. They collect in pillows, mattresses, and box springs, in carpeting and upholstered furniture, and wherever house dust accumulates (along blinds and curtains, on books and stuffed animals and other "knick-knacks" on counters and shelves). As you walk into the bedroom, shuffle along the carpeting, ly down on the mattress and rest your head on the pillow, the microscopic droppings of the dust mites are lifted into the air and made available for inhalation. The same happens when dusting with a dry mop or feather duster. Even vacuuming can distribute the allergen particles into the air. They are small enough to pass through most conventional filter bags and can be blown out the exhaust end of the vacuum cleaner.

To find if you are allergic to dust mites, consider your own experiences when exposed to dust, and discuss allergy testing with your doctor.

Here's how you can have a big impact on the dust mite exposure in your bedroom. First, wrap your mattress, box springs, and pillows in plastic, zippered, allergy-proof wraps. These are often available at large department stores or can be obtained from supply houses that specialize in allergy-related products (for example, National Allergy Supply, 1-800-522-1448)[check phone #]. As an added protection you can tape over the zippers to eliminate any escape of the mite particles. Sheets and pillow cases are used as usual, but they should be washed in hot water weekly to kill the mites that accumulate on these surfaces.

Use zippered, allergy-proof wraps for pillows, mattress, and box springs.

The other major reservoir of the dust mite allergen is carpets and rugs. The best solution, if at all possible, is to take up the carpeting. At most, use small area rugs over hardwood floors. As an alternative, vacuum the carpeting using special small-pore vacuum filter bags to trap the mite allergen within the vacuum cleaner. Remove unnecessary "dust collectors" from open surfaces, and when dusting use a wet cloth to minimize dispersing the mite particles into the air.

Eliminate carpeting, especially in the bedroom.

Because dust mites prefer high humidity, you can inhibit their growth by maintaining the indoor humidity less that 50%. To be rigorous in pursuit of a dry indoor climate, you might obtain a meter to measure the humidity (called a hygrometer) and run a dehumidifier when necessary. Another approach is simply not to run a humidifier in the bedroom during the winter. Think of the humidifier as a "dust mite feeder."

Keep indoor humidity low.

Remember too that dust mites feed on animal danders as well as human scale. Indoor warm-blooded pets contribute to the growth of dust mites. At a minimum, it can help to keep the pets out of the bedroom, even if you believe that you are not directly allergic to your pet cat or dog.

Shedding pets contribute to dust mite growth.

What is to be gained from all of this effort? The goal is less cough, less wheeze, less shortness of breath, and fewer awakenings overnight with asthmatic symptoms. In fact, in one study it was shown that with these measures applied in the home and especially in the bedroom, persons with dust-mite allergic asthma became less sensitive to all triggers of asthma. Their bronchial passageways became less sensitive or "twitchy" — that is, less asthmatic in general. And that, after all, is the long-term goal of all of our treatment for asthma.

The reward for these efforts: fewer symptoms of asthma.