House Dust Mite Allergy

Dust mites are microscopic insect-like creatures which are present in the home during all times of the year. Their main food source is human dander (dead skin flakes). The fecal material excreted by the dust mites is the actual allergenic substance. They tend to thrive during times of high humidity and in areas of the home where human dander is present in large amounts. Thus, dust mites are found in the greatest numbers in the bedroom, upholstered furniture, stuffed toys and carpeting. Symptoms of dust mite allergy are most often present year round, but usually worsen in the winter months. Symptoms of dust mite allergy may involve the upper airway (nasal congestion, sneezing, runny nose), lower airway (cough, wheeze, shortness of breath), eyes (itching and redness) or skin (eczema).

It is quite important for dust mite allergic individuals to practice dust mite avoidance within the home. Medications or immunotherapy (allergy shots) should not be thought of as replacements for avoidance measures. There are many ways to decrease the numbers of dust mites within the home, including bedding encasements, humidity control and others listed below.

Mattresses, box springs, comforters and pillows should be encased in zippered plastic or special allergen-proof fabric covers. They are not needed for waterbed mattresses which contain no stuffing materials. Theses covers may be purchased at specialty stores or by special order from several reputable companies. For your convenience, our office provides ordering information from several sources. Bedding materials should be washed in hot water (greater than 130 degrees F) every one to two weeks.

In addition, the humidity level within your home should be kept at or below 50%. Humidifiers should not be used, and dehumidifiers may be necessary to maintain this level. Carpet shampooing is not recommended, as the residual moisture may promote dust mite growth. Carpet cleaning by a dry process, such as “Chemdry”, is a better choice.

Wall-to-wall carpeting should be kept to a minimum, as should large area rugs (unless they can be washed or dry cleaned regularly). Weekly vacuuming is essential in carpeted areas, and is best accomplished with a HEPA-equipped vacuum cleaner. Whenever possible, the mite-allergic individual should not be doing the housecleaning, or should wear a mask during the process. HEPA room filters, while helpful for other allergens, have not been proven effective in dust mite control. Ventilation duct cleaning has not been proven helpful either.

Nonessential books, toys and clothing should be put away in drawers or closed cabinets. Stuffed animals should be washed weekly and not be kept on the bed. Those that cannot be washed may be placed in a freezer overnight and then thoroughly vacuumed and dried. Pesticides specifically marketed for dust mite control offer only temporary relief, and have led to upper and lower airway irritation (worsening or nasal and asthma symptoms), and thus are not recommended.

Diplomates of the American Board of Allergy and Clinical Immunology