allergen Dermatophagoides farinae American house dust mite An allergen that is an American house dust mite, microscopic, insect-like pests that commonly live in house dust. They feed on flakes of dead skin, or dander, that are shed by people and pets. These tiny creatures are a big source of allergens and can worsen allergies and asthma. Dust mites can live in mattresses, bedding, upholstered furniture, carpets, and curtains in your home. NCBITaxon:6954 OMIT:0022964