House Dust Allergy
- What is house dust?
- Where do dust mites live?
- How can I control cust mites?
What is house dust?
Many people sneeze or sniffle in dusty areas, and it's no wonder. The ingredients of house dust that can cause allergic reaction include molds, pet and human dander, and cockroach waste. However, the dust mite - found in ordinary house dust - plays the most significant role in all the sniffling and sneezing. The dust mite is a microscopic, spider-like creature which is found in homes. It is primarily in carpets, mattresses and upholstered furniture and thrives in humid and warm conditions. The dust mite feeds on shed scales from human skin! The waste products produced by these mites are highly allergenic (able to cause allergic reaction). These waste products continue to cause allergic symptoms even after the mite that produced them has died.
Where do dust mites live?
The greatest numbers of dust mites can be found in carpets, which provide the best conditions (warmth, humidity and food) for their growth. Mites are also present in mattresses, pillows, blankets, upholstered furniture, curtains and similar fabrics. Female mites can lay 25 to 50 eggs, with a new generation produced every three weeks. It is therefore easy to see why carpets may contain such large numbers of living and dead mites.
How can I control dust mites?
Scientific studies of dust-allergic patients have shown that taking steps to minimize dust mite exposure in the bedroom can lead to a decrease in allergic symptoms and medication requirements. The reason for the focus on the bedroom is that most people spend one-third or more of their day there. As a result, it is often the room with the greatest number of dust mites. Important dust control measures are noted below:
- Encase the mattress, box spring and pillows in zippered, dust proof covers. Eliminate "dust catchers" from areas where you spend the most time--often the bedroom and living room or den. Use polyester fiberfill pillows (no kapok or feather pillows).
- Preferably, floors should be vinyl or wood, and covered with washable area rugs only. Carpeting should be avoided. However, if carpeting is present, vacuum thoroughly 1-2 times a week.
- Avoid heavy curtains and venetian blinds, if possible. Use window shades instead. If curtains are used, launder them periodically.
- Wash blankets in hot water periodically. Avoid wool and down blankets.
- Someone other than the allergic individual should do the house cleaning, especially "spring cleaning". If the allergic individual does the cleaning, he/she should wear a mask while doing so, and then leave the house or room for 30 minutes while airborne dust settles. It is also a good practice to dust with a damp cloth.
- Air conditioners can control the high heat and humidity that stimulates mite growth. Use a dehumidifier in damp basements. Run a dehumidifier or air conditioner during periods of high humidity, particularly from spring through fall. You should also clean heating/air conditioning filters monthly. "H.E.P.A." air cleaners can remove airborne dust, but not the dust mites in bedding or carpets. Inexpensive tabletop models are not effective. Covering hot air vents with filters is beneficial.
- Avoid wall pennants, macrame hangings, unnecessary pillows, books and magazines, stuffed animals and other dust collecting knickknacks. Furniture should be wood, leather, plastic or metal--as upholstered furniture tends to trap dust and become a site for dust mites to grow.
- Keep all clothing in a closet with the door shut.
- If using a humidifier in the winter, avoid over-humidification. Mites grow best at 75-80% relative humidity and cannot live under 50% humidity. Maintain the relative humidity at 40-50% (this can be measured using a humidity gauge).
- If you are planning to move, select an apartment or house that is above-ground (i.e. no basement living areas), has wooden floors, and has bedrooms on the second floor (i.e. not over concrete which remains damp).
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Last Reviewed: Oct 19, 2010