Dust mite allergy is one of the most common causes of year round allergies and asthma.   It is estimated that 55% of children with asthma are allergic to dust mites.   Dust mites are also associated with atopic dermatitis (eczema).   There is evidence that exposure to high levels of dust mites in the first 2-3 months of life is a risk factor for the development of asthma.     

What are dust mites?
Dust mites are very small 8 legged organisms which fall into the spider category (along with chiggers and ticks).   They are so small (⅓ of a millimeter, or about 1/100th of an inch) that they can’t be seen without the use of a microscope.    They feed on dead skin and absorb moisture from the air through their skin.   They are mostly found in bedding, stuffed animals, carpets,  upholstered furniture, and clothes.   It is estimated that a mattress may contain 100,000 to 10 million dust mites.   Their average life span is between 20-30 days, although some can live
up to 80 days.     Dust mites thrive in a dark, warm humid environment.  

Individuals allergic to dust mites are sensitive to their digestive enzymes which are found in high levels in mite fecal pellets.   

How to minimize dust mite allergens in the home
There are several measures that have been demonstrated to be useful in order to minimize dust mite allergy:

• Enclose mattresses, box springs, and pillows with dust mite covers.   These specially made covers trap dust mites in.   Make sure you buy good quality covers – they cost a little bit more, but cheap ones will tear quickly and cost you more in the long run.   You can get dust mite covers from local stores such as Bed Bath and Beyond, Wal-Mart or Target, or online at sites such as National AllergyorAllergy Control.  
  
• Wash your bedding in hot water (130º F) weekly.
  
• If possible, remove wall-to-wall carpeting and replace it with linoleum, vinyl, wood, or tile floors.   If not possible, vacuum the carpet 1-2 times per week.  Make sure the vacuum cleaner that has a HEPA filter.
  
• Avoid humidifiers.   Anything below 50% humidity will help keep dust mite count low.    In the summer, running the AC will keep the humidity low.  
  
• Minimize stuffed toys; wash those you keep at least monthly.   Placing a stuffed animal in the dryer for 20 minutes is also effective in removing dust mites.
  

Diagnosis of dust mite allergy
Dust mite allergy can be identified with a skin prick test or blood test.

Treatment of dust mite allergy
Along with dust mite avoidance, medications such as antihistamines and
steroid nose sprays can help improve the symptoms of dust mite allergies.    
Allergy shots and allergy drops have been demonstrated to be effective for the long term treatment of dust mite allergies

Do you want to know more about dust mites?   The first video below has a great film of dust mites eating.   The second one is a good overview of what dust mites are, their impact, and how to minimize their exposure.