Before you wage war on dust mites by buying new pillows, mattresses and protective covers, read the latest Patient Money column. As Lesley Alderman reports, dust mites may seem disgusting, but unless you’re allergic, you don’t need to worry about them.

Dust mites are microscopic creatures, about 0.4 millimeters in length, that feast on flakes of human skin. Their feces contains a substance called DerP1, a very potent allergen. People who are allergic to dust mites may have asthma-like symptoms, eczema or chronic sinus problems.

Many of us believe that bed linens, pillows and mattresses must be replaced regularly in order to prevent them from becoming home to vast colonies of these nasty critters, lest their feces spread and cause allergic reactions in family members. According to most experts, the truth is a bit more prosaic. People who have allergies to dust mites should indeed take measures to protect themselves. But everyone else can skip the expensive trips to Linens “R” Us.

To learn more, including how to be tested and what measures will help combat the allergen, read the full column, “Who Should Worry About Dust Mites (and Who Shouldn’t),” and then please join the discussion below.