Asthma & Dust Mites

Dust Mite Facts

Dust mites are a common cause of allergy problems.
Dust mites are so small they can only be seen with a microscope. They belong to the spider family.
Dust mites live up to 4 months. Each female can lay 100 eggs.
Dust mites eat dead skin flakes and produce waste called fecal pellets.
One mite may produce 20 fecal pellets a day. The pellets remain long after the mite is gone.
Allergy problems are mainly caused by these fecal pellets.
Most dust mites are found in your mattress and pillow. Dust mites also live in carpets, furniture and stuffed toys.
They like warm, moist places (temperature 20-25C, humidity above 50%)
Anyone allergic to dust mites should try to avoid them. This may decrease problems and the need for medicine.

Important Control Measures

At least 1/3 of a child’s time is spent in the bedroom. Focus on this room.
Encase the mattress with an airtight, mite-proof cover. Covers come in a range of prices.
If mite-proof covers cost too much, wrap the mattress in heavy plastic. Seal all seams with tape. Use a fitted, washable, quilted mattress cover for comfort over the plastic. Wash it with the bedding.
Wash bedding once a week in hot water. Dry in a hot dryer for at least 45 minutes.
Put pillows, blankets and comforters in the dryer on the hot cycle for 45 minutes every two weeks. Replace pillows every 2-3 years.
If possible, avoid carpet in the bedroom.
Avoid clutter in the bedroom. Remove dust collectors.
If a child has a favorite stuffed toy that cannot be washed, place in a hot dryer for 45 minutes every two weeks.
Vacuuming removes only surface dust. Live mites are hard to vacuum. Vacuums which use a water system are no better than normal vacuums.
Air cleaners are not helpful in removing dust mites or fecal pellets.
Do not use a humidifier in the bedroom. If humidity in the home is high, use a dehumidifier.
Clean all hard surfaces at least once a week with a damp cloth.
Putting things in the freezer will kill the dust mites. It does not affect the fecal pellets.
If a child has an allergy to dust mite, their bedroom should not be in the basement.

Buying a Dust Mite Cover

Many stores sell covers that say they protect against dust mites. Not all do.
Covers must completely enclose the mattress, not just cover the top.
Openings in the material called pores should be less than 5 microns. Less than 2 microns is best.
Covers that allow air to move through the material are air permeable. Air permeable covers cost more, but will be more comfortable.
Vinyl and other low cost covers can be found at most stores that sell bed linen. More expensive covers can be obtained through specialty stores.
Speak to your Certified Asthma Educator or health care provider, if you need further information.