In this Article

• What are allergens?
• What actually is house dust?
• What are dust mites?
• What conditions are most favorable to dust mites?
• How do dust mites cause allergic symptoms?
• Can cockroaches cause allergic symptoms?
• What about allergies to molds?
• What about allergies to pets?
• What about allergies to indoor pollens and houseplants?
• Indoor Allergens At A Glance
• Pictures of Common Allergy Triggers - Slideshow
• Indoor Allergens Glossary
• Indoor Allergens Index

What are dust mites?

Dust mites, which were discovered in 1964, are microscopic arachnids (resembling tiny spiders). They are about 1/3 mm in length and are not visible to the naked eye. They have eight legs, are blind, and naturally live indoors. Their presence does not indicate that the house is dirty. This is because usual cleaning procedures, such as vacuuming and dusting, do not eliminate them.

Dust mites have "sticky" pads at the ends of their legs that help them to firmly attach to fibers, which allows them to live deep within carpeting, upholstery, and mattresses. Most of the mites found in houses are from the Dermatophagoides family, with pteronyssinus and farinae being the most common species. (Dermatophagoides comes from Latin and means skin-eating. Pteronyssinus comes from Latin and means feather-loving. Farinae is Latin for flour.) Fortunately, dust mites do not bite, spread disease, or actually live on humans.

What conditions are most favorable to dust mites?

Dust mites thrive in warm, humid places. The ideal temperature for dust mites ranges from 65 to 80 degrees F, a common range for indoor room temperatures. Since dust mites have no means of drinking, they are totally dependent on the humidity surrounding them for water. They live best at a relative humidity above 55%. However, also be aware that monitoring the humidity really isn't sufficient to control dust mites. As the humidity falls, dust mites will retreat from the surface. However, even in very dry conditions, it can take quite a few months to eliminate the dust-mite population.

Dust mites derive their food supply from human secretions and the skin cells we shed. (The average human sheds up to 1.5 grams of skin particles per day. A gram is about the weight of a paper clip.) The mites thrive in articles such as feather pillows and stuffed animals that collect sloughed skin cells and secretions. The most favorable conditions for dust mite growth are found in the bedroom. Their favorite breeding grounds are mattresses, pillows, and box springs, as well as blankets, curtains, carpeting, and other fabric items in the room.

The perfect climatic conditions for dust mites occur in North America in the mid- and southern Atlantic coast, Gulf Coast, central Midwest, Pacific Northwest, and British Columbia. Dust mites are rarely found in dry climates where the elevation is over 5,000 feet above sea level.

From the Doctors at MedicineNet.com

ELISA Tests - Source:MedicineNet Eczema - Get information about eczema causes, skin symptoms, diagnosis and treatment. Types include dyshidrotic, atopic dermatitis, nummular, varicose and seborrheic eczema. Source:MedicineNet Asthma - Get the facts on asthma symptoms, signs, diagnosis, causes and triggers of asthma attacks, treatment information, medication, inhalers, and management. Asthma in children and exercise-induced asthma are types of asthma. Source:MedicineNet Read 33 more Indoor Allergens related articles ... Kids' Allergies: Schoolwork Can Suffer