Dust Mites and Associated Allergic Reactions

Dust mites are part of the arachnid family which includes spiders, ticks and other 8 legged creatures. Both species common to North America are very hard to see, being about 1/3 of a millimeter in length. Higher relative humidity in a home increases the development of these creatures. Their diet includes human skin, pollen, fungi, bacteria, and animal dander. Dust mites are found in all dwellings and workplaces. They usually do not cause a significant problem to health unless their numbers increase causing certain individuals to become sensitive to their allergens.


Dust mite allergens are probably the most common cause of allergic rhinitis, a condition similar to pollen allergy. They may also be able to trigger asthma attacks. The allergens come from both the mite itself and the droppings that it produces. In both cases, a protein produced causes the reaction when it comes in contact with the skin or is inhaled. Each gram of house dust may contain up to 500 mites, with each mite producing 10 to 20 waste particles per day. These waste particles are so small that they become air born easily.


Not all people will become sensitive to the protein that the mite produces. A skin prick test or a RAST test done on a blood sample will help determine if you are having allergy symptoms related to the mite. Desensitization injections called Systemic Immunotherapy may be prescribed to treat pure house dust mite allergy that fails to respond to avoidance measures or common medical therapy.


Common avoidance measures include: Keeping the humidity to below 50%; using a HEPA filter air cleaner; using a low pile carpet; washing throw rugs frequently; dusting and vacuuming at least twice a week with a HEPA filtration vacuum or central vacuum plumbed to the outside; encasing mattresses, box springs, and pillows in non-allergenic, plastic zippered encasings; avoiding down and feather bedding materials; washing bedding frequently in water over 160 degrees Fahrenheit; and keeping pets from bedrooms or sleeping areas.


Following the avoidance measures in most cases will provide relief to individuals sensitive to the proteins. If you just haven’t quite been able to figure out what is triggering allergies or asthma attacks in your family, try using the avoidance measures to help provide some comfort. Controlling dust mites may only be one factor in limiting the overall indoor air quality problems in the home. For further information on overall indoor air analysis or testing, contact a hygienist, indoor air quality specialist, or your allergist.

For more information on allergens, visit my link to frequently asked questions regarding allergens at http://www.environmentalhealthguy.com/faq_category.php?catID=24


Christopher A. Hinz
Environmental Health Specialist
Waushara, Green Lake, and Marquette Counties