One in four Americans are sensitive to dust mites. If we include other components of house dust (pollens, animal danders, cockroaches and molds), the number is even higher.
Dust mites are arachnids, like spiders and ticks. They thrive in warm, humid climates; temperatures above 70 degrees Fahrenheit and humidity over 70%. Mites live off water in the air and ingest particles of human skin and animal dander. This is why the concentrations are so high in your mattress and bedding. However, dust mites are not bed bugs, they do not bite nor carry disease. Mites are only harmful to those people who are allergic. Dust mite allergy can result in several allergic conditions:
1. Allergic rhinitis: runny nose, congestion, sneezing and itching.
2. Asthma: cough, wheezing, shortness of breath.
3. Atopic dermatitis: eczema, itching.
People who are allergic to dust mites react to proteins within the bodies and feces of the mites. These particles are found mostly in pillow, mattresses, carpeting and upholstered furniture. They float in the air when anyone vacuums, walks on a carpet or disturbs bedding, but settle out of the air soon after the disturbance is over.
Research has confirmed that targeted avoidance (environmental control aimed at relevant triggers) can be as effective as medications in reducing symptoms. Here are some tips:
• Focus on reducing dust mite levels in the bedroom. Keep indoor humidity below 50%. This may require a dehumidifier. Do not use vaporizers or humidifiers. Use ventilation fans in bathrooms and kitchen. Use a vacuum with a HEPA filter. If you are allergic, wear a N95 filter mask while dusting, sweeping or vacuuming. Even better, find someone else to clean when you are not at home.
◦ Encase mattresses and pillow with ‘mite-proof’ covers.
◦ Wash all bed linens weekly using hot water ( > 130°).
◦ Remove wall-to-wall carpets.
◦ Remove plants, soft toys, cushions and upholstered furniture.
◦ Treat stuffed animals with fire and ice: Dust mites die at freezing temperatures. Put pillows and children’s stuffed animals in plastic bags and put them in the freezer for 24 hours. Alternatively, put toys in a fabric bag and place them in the dryer for 10 minutes. Remember to take off anything that could melt.
• Acaracidal sprays (i.e. tannic acid) can temporarily reduce mite levels in airborne, furniture and carpet dust. Application of liquid nitrogen to the mattress and carpets is slightly more effective and much more dangerous.
• Install a high efficiency media filter with a MERV rating of 11 or 12 in the furnace and air-conditioning unit. Change the filter at least every three months (with the change of the seasons).
• Portable HEPA filter air-cleaners are less effective at reducing dust mite levels. This intervention may be worthwhile for pet allergy (esp. cats).
There are more than 30 trials demonstrating the effectiveness of bed encasings for asthma. Financially, the one time cost is significantly less than a monthly copay. Unfortunately, the clinical benefit of covers alone was small. A complete program, including acaricides and extensive bedroom based environmental control is necessary. Benefits include decreased allergy and asthma symptoms, less medications and more savings.