How mites can cause and trigger allergic disease  When people with a family history of allergy are repeatedly exposed to house dust mite droppings, they can develop a specific allergy to mites. Once allergy is diagnosed and allergic reactions become frequent, then allergic disease can develop. Continued exposure to the mite allergens can then become a trigger for chronic symptoms. Rhinitis (hay fever) is a good example of how mites can cause and trigger chronic allergic disease. Initial contact with mite droppings may have resulted in annoying symptoms of repeated sneezing or a constant runny nose. Further exposure can lead to a permanently stuffy or ‘bunged-up’ nose and losing the sense of smell. Once chronic symptoms such as these become established, it is difficult to tell when further allergen exposure takes place because the allergic reactions are joined in one long symptom. Chronic rhinitis is clinically recognized as a risk factor for the development of allergic asthma. See - Time Line: 1996 (12) and 2000 (16)  Other Public Research What is the house dust mite How mites can cause and trigger allergic disease  What can be done to reduce the health risks from mite exposure What other ‘events’ make mites more harmful . Ozone from photocopiers and mite allergens  House dust mites can make lung inflammation worse Life in house dust mite droppings Flu and the house dust mite Dog dermatitis is caused by specialized allergens from house dust mites.  All 20 allergens from house dust mites must be taken into account in assessing reactions Skin Testing for Allergies Skin prick testing after 14 years