Dust Mites

It was once believed that dust itself was the cause of allergic reactions. But now it’s known that tiny creatures called dust mites, which inhabit the dust, are the problem. Dust mites are 8-legged microscopic animals that are related to spiders and ticks. Up to 500 dust mites can live in one gram of dust. (One gram weighs about as much as a paper clip.).

Fortunately for those living 3000 or more feet above sea level, dust mites can’t survive at high altitude. They require water to survive, so they thrive best in humid regions. Their principal food is shed human skin. This dietary preference causes them to gravitate towards areas of human habitation. And, with the average human sloughing off one pound of dead skin per year, dust mites typically have plenty to eat. Too small to be seen, their droppings and their decaying bodies can cause allergic reactions when inhaled by people with dust mite sensitivities, or when dust mites come into contact with their skin.

The symptoms of dust mite allergies are like those seen in other common allergies—sneezing, wheezing, itchy eyes, cough, and other symptoms common to allergic rhinitis. Up to 10 percent of the U.S. population is allergic to dust mite, and in some regions, dust mites may play a role in up to 90 percent of allergic asthma cases.

Where Dust Mites Live

Bedrooms are a prime habitat, and a used mattress can contain 100,000 to 10 million mites. Dust mites also can be found anywhere dust collects, such as drapes, stuffed toys and carpets. Dusty houses can make the problem worse. But clean houses aren’t immune. Normal cleaning processes aren’t typically adequate to reduce the dust mite population.

Bedding provides the perfect warm environment for dust mites, with a constant supply of dead skin. That’s why dust mites are often the culprit when people with asthma have more attacks at night.