Dust mites have been associated with a range of respiratory and dermatological allergies, such as asthma and eczema. The main component of dust is shed skin flakes, which is the mite's preferred food source. This test is used to detect and quantify the presence of the two major dust mite (Dermatophagoides pteronyssinus and Dermatophagoides farinae) allergens, Der p1 and Der f1. Sensitive individuals have allergic responses to this protein which is found in high concentration in the mite's faeces.