Inhaling the house dust allergen triggers rhinitis allergica or bronchial asthma. People with allergies to house dust usually also have allergic reactions to house dust mite fecal material and cast skins. Studies have shown that the most potent house dust allergens can be extracted from the feces produced by dust mites. The rest of this fact sheet, based on Chapter 10, “Mites,” in Common-Sense Pest Control by Olkowski, Daar and Olkowski, will discuss biology of dust mites and will emphasize non-chemical control tactics. An allergist, a medical doctor specially trained to treat allergies, should be consulted for proper diagnosis and treatment of allergies. One of the most strongly allergenic materials found indoors is house dust, often heavily contaminated with the fecal pellets and cast skins of House Dust Mites. Estimates are that dust mites may be a factor in 50 to 80 percent of asthmatics, as well as in countless cases of eczema, hay fever and other allergic ailments. Common causes of allergy include house dust mites, cat dander, cockroach droppings and grass pollen. Symptoms are usually respiratory in nature (sneezing, itching, watery eyes, wheezing, etc.), usually NOT A RASH. However, there are reports of a red rash around the neck. Other allergic reactions may include headaches, fatigue and depression. The wheeze-inducing proteins are digestive juices from the mite gut which are quite potent. An exposure to the mites in the first, crucial year of life can trigger a lifelong allergy. There is no cure, only prevention. One must control house dust mite levels. Beds are a prime habitat (where 1/3 of life occurs). A typical used mattress may have anywhere from 100,000 to 10 million mites inside. (Ten percent of the weight of a two year old pillow can be composed of dead mites and their droppings.) Mites prefer warm, moist surroundings such as the inside of a mattress when someone is on it. A favorite food is dander (both human and animal skin flakes). Humans shed about 1/5 ounce of dander (dead skin) each week. About 80 percent of the material seen floating in a sunbeam is actually skin flakes. Also, bedroom carpeting and household upholstery support high mite populations. The protein substances in the dust mite feces produces antibodies in humans who are allergic when these are inhaled or touch the skin. These antibodies cause the release of histamines which causes to nasal congestion, swelling and irritation of the upper respiratory passages. The Mayo Clinic, WebMD and NIH collectively provide this list of typical symptoms of an allergy to dust mites; You may experience all or just some of them: Hay fever, Watering eyes, Runny nose, Sneezing, Asthma, difficulty in breathing, Infantile eczema, Itchy, red or watery eyes, Nasal congestion, Itchy nose, roof of mouth or throat Postnasal drip, Cough Facial pressure and pain Frequent awakening, Swollen, blue-colored skin under your eyes. In a child, frequent upward rubbing of the nose.