House dust mites are a significant factor in causing allergies in humans. Five percent of the population is believed to be allergic to house dust- and one of these types of allergic reactions can be asthma attacks. The growing prevalence of asthma in the U.S. affects 14-15 million people, 4.8 million of them under 18 years of age.

Asthma caused 198,000 hospitalizations and 342 deaths among people less than 25 years in 1993. Some 45-85% of asthmatics has been shown by skin patch test to be sensitive to mites, compared to 5-30% for the general population.

House dust mites are major producers of the allergens-substances that cause allergies-in dust, known medically as Group 1 human allergens. Symptoms of house dust allergies include asthma, runny nose, watery eyes, sneezing, and breathing difficulties and skin inflammation.