Wash in hot water. Dust mites thrive in warm and humid places, so the number one most likely place to find these little critters is in bedding. Dust can cause many problems for people that suffer from allergies. Dust contains many allergens, so try to make your home as dust free as possible. Drapes, blinds, knick knacks to name just a few places, where dust collects.
Pets cats are particularly the cause in animal induced allergies.
The allergens caused by cats are in their saliva and skin. Some tips are to bath your cat at least once a week, and block off access to your bedroom if you are a allergy sufferer. Short of giving the animal away, there are steps to try to relieve symptoms. Don't wait to clean out possible mildew and mold producing spots around the home. If you can see mold and mildew you have waited far to long.