Dust mites are microscopic, insect-like pests that feed on dead human skin cells and thrive in warm, humid environments. They are not parasites that bite, sting or burrow into our bodies. Instead, people who are allergic to dust or dust mites are reacting to inhaling proteins in dust that comes from dust mite feces, urine or decaying bodies. Any inflammation of the nasal passages caused by dust mites is considered a dust allergy. Dust mites are not harmful to everyone, but for those who are allergic to them, they can cause a great deal of discomfort. Symptoms of a dust mite allergy include sneezing, coughing, itchy eyes, a runny nose, and difficulty breathing. If you suspect you may be allergic to dust mites, it is important to see a doctor so they can confirm the diagnosis and help you find relief from your symptoms.