Many people recognize allergy symptoms such as a runny or stuffy nose, itchy, watery eyes and sneezing (allergic rhinoconjunctivitis) from dust exposure related to common household chores such as vacuuming, sweeping, and dusting. House dust exposure can also trigger asthma symptoms such as wheezing, coughing, chest tightness and shortness of breath.
Why does house dust cause allergic reactions?
House dust is a mixture of many substances. Its content may vary from home to home, but the most common allergy triggers are:
· Dust mites
· Fungi (Mold)
· Animal Dander (house pets as well as rodents)
Being ” allergic” to these components of house dust means that your immune system produces antibodies called Immunoglobulin E (IgE), that react with proteins unique to the substance. Exposure to only small amounts of the offending allergen produces an allergic inflammatory response and allergy symptoms.
Is dust allergy a sign of a dirty house?
No. A dirty house can make a house dust allergy problem worse, however. Normal housekeeping may not be enough to get rid of house dust allergy symptoms. This is because many of the substances in dust cannot be removed by normal cleaning procedures. Vigorous cleaning methods can actually put more dust into the air making symptoms worse. Even if the house is very clean, some people are so allergic that even minimal exposures may trigger their symptoms.
Dust Mite Allergy
Dust mites are the most common cause of allergy from house dust. They belong to the family of eight-legged creatures called arachnids that also include spiders, chiggers and ticks. Dust mites are hardy creatures that live and multiply easily in warm, humid places. They prefer temperatures at or above 70 degrees Fahrenheit with a relative humidity of 75 percent to 80 percent. They die when the humidity falls below 40 percent to 50 percent. They are not usually found in dry climates.
Dust samples from homes in Arizona rarely contain significant levels of house dust mite. These is an exception however. Home that use evaporative coolers have humidity levels high enough to support house dust mites. It is also possible that using a room humidifier regularly will increase humidity to levels that will encourage mite infestation.
High levels of exposure to dust mite are an important factor in the development of asthma in children. People who are allergic to dust mites react to proteins within the bodies and feces of the mites. These particles are found mostly in pillows, mattresses, carpeting and upholstered furniture. They float into the air when anyone vacuums, walks on a carpet or disturbs bedding, but settle out of the air soon after the disturbance is over.
Dust mite-allergic people who inhale these particles frequently experience allergy symptoms. There may be many as 19,000 dust mites in one gram of dust, but usually between 100 to 500 mites live in each gram. (A gram is about the weight of a paper clip.) Each mite produces about 10 to 20 waste particles per day and lives for 30 days. Egg-laying females can add 25 to 30 new mites to the population during their lifetime.