AIR CONTROL

Air filters—either added to a furnace or a room unit—can reduce the levels of allergens. Electrostatic and HEPA (high-efficiency particulate absorption) filters can effectively remove many allergens from the air. If they don’t function right, however, electrostatic filters may give off ozone, which can be harmful to your lungs if you have asthma.

A dehumidifier may help because house mites need high humidity to live and grow. You should take special care to clean the unit frequently with a weak bleach solution (1 cup bleach in 1 gallon water) or a commercial product to prevent mold growth. Although low humidity may reduce dust mite levels, it might irritate your nose and lungs.