House Dust Mite Allergy

House dust mites are the most ubiquitous source of indoor allergens inducing allergies. Signs of dust mite allergy include sneezing and runny nose. Many people with dust mite allergy also experience signs of asthma, such as wheezing and difficulty breathing. Dust mites are a common cause of asthma in children.

The main species that cause allergic sensitization are Dermatophagoides pteronyssinus and Dermatophagoides farinae.

Dust mites are sometimes called bed mites. Dust mites, close relatives of ticks and spiders, are too small to see without a microscope. A dust mite measures only about one-quarter to one-third of a millimeter. They are too small to see with your eyes alone. Dust mites eat skin cells shed by people, and they thrive in warm, humid environments. They are not usually found in dry climates. In most homes, bedding, upholstered furniture and carpeting provide an ideal environment for dust mites. The body parts and the waste of dust mites are the substances that cause an allergic reaction. Most dust mites die in low humidity levels or extreme temperatures. But they leave their dead bodies and waste behind. These can continue to cause allergic reactions. In a warm, humid house, dust mites can survive all year.

Symptoms

  • Sneezing
  • Nasal congestion
  • Runny nose Itchy, red or watery eyes
  • Itchy nose or throat
  • Postnasal drip
  • Cough
  • In a child, frequent upward rubbing of the nose

If your dust mite allergy contributes to asthma, you may also experience:

  • Difficulty breathing
  • Wheezing sound when exhaling
  • Chest tightness or pain
  • Sleeping problems caused by shortness of breath, coughing or wheezing

Some symptoms of dust mite allergy, such as a runny nose or sneezing, are similar to those of the common cold. Often it is difficult to know whether you have a cold or an allergy. If symptoms persist for longer than one week, you might have an allergy. If your signs and symptoms are severe — such as severe nasal congestion, difficulty sleeping or wheezing — see your doctor.

Diagnosis

Allergy testing will show if there is allergic sensitization to dust mites. Your doctor can use either a blood test or skin test to aid in the diagnosis. Medical history, symptoms, physical examination and the test results will help your doctor to find the right diagnose.

The following factors increase your risk of developing a dust mite allergy:

  • Having a family history of allergies.
  • Being exposed to high levels of dust mites, especially early in life, increases your risk.
  • Being a child or a young adult. You’re more likely to develop dust mite allergy during childhood or early adulthood.

Treatment

Avoidance is the best way to manage a dust mite allergy. However, it’s impossible to completely eliminate dust mites from your environment. If you can minimize your exposure to dust mites, you should expect fewer allergic reactions or the reactions should be less severe, but you may also need medications to control symptoms.

Allergy medications to improve nasal allergy symptoms:

  • Antihistamines
  • Corticosteroids delivered as a nasal spray
  • Decongestants can help shrink swollen tissues in your nose
  • Leukotriene modifiers block the action of certain immune system chemicals.

Other therapies

  • Immunotherapy. SCIT/Allergy shots (subcutaneous specific immunotherapy) or SLIT (sublingual immunotherapy) tablets.

Prevention

Having dust mites doesn’t mean your house isn’t clean. You can’t completely eliminate dust mites from your home, you can significantly reduce them. Here are some tips how you can reduce the number of dust mites:

  • Use allergen-proof bed covers. Studies show that more dust mites live in your bedroom than anywhere else in your home. So this is the best place to start. Cover your mattress and pillows in dustproof or allergen-blocking covers. These covers are made of a material with pores too small to let dust mites and their waste product through.
  • Wash your sheets and blankets weekly. Wash all sheets, blankets, pillowcases and bedcovers in hot water that is at least 60° C or 140° F to kill dust mites and remove allergens. Freezing nonwashable items for 24-48 hours also can kill dust mites, but this won’t remove the allergens.
  • Buy washable stuffed toys. Wash them often in hot water and dry thoroughly or put stuffed toys in a plastic bag and freeze them for 24-48 hours, then brush them well. This also can kill dust mites.
  • Avoid bedcovers that trap dust easily and are difficult to clean frequently.
  • Keep humidity low. Maintain a relative humidity below 50 percent in your home.
  • Avoid wall-to-wall carpeting, curtains, blinds, upholstered furniture and down-filled covers and pillows in the bedroom.
  • Have someone without a dust mite allergy clean your bedroom. If this is not possible, wear a filtering mask when vacuuming or dusting.
  • Use a damp or oiled mop or rag rather than dry materials to clean up dust. This prevents dust from becoming airborne.
  • Vacuum regularly. Special HEPA filter vacuum cleaners can help to keep mites and mite waste from getting back into the air. Stay out of the vacuumed room for about two hours after vacuuming. Vacuuming carpeting and upholstered furniture removes surface dust — but vacuuming does not remove most dust mites and dust mite allergens. A large amount of the dust mite population may remain because they live deep inside the stuffing of sofas, chairs, mattresses, pillows and carpeting.
  • Remove carpeting and other dust mite habitats. If possible, replace wall-to-wall bedroom carpeting with tile, wood, linoleum or vinyl flooring.
  • Wash rugs in hot water whenever possible. Cold water isn’t as effective. Dry cleaning kills all dust mites and is also good for removing dust mites from living in fabrics.
  • If you have central furnace and air conditioning unit, use a HEPA filter. This can help trap dust mites from your entire home.