Michael L. Lewin, MD
Michael L. Lewin, MD, an allergist who has been practicing for 30 years. He has offices in New York City and Wilton, Connecticut, and is a faculty member of Weill Cornell Medical College in New York City. LewinAllergy.com
More than half of all Americans test positive for at least one kind of allergen. But there’s one culprit that often gets overlooked by allergy sufferers.
What you may not realize: Dust mites, which thrive in warm, humid weather, are one of the most common household triggers for allergies and asthma. Dust mites are tiny, eight-legged creatures that are too small to be seen by the naked eye, but they can wreak havoc if you are allergic to them.
Dust mites lurk in beds, carpets, draperies and upholstered furniture and surfaces. Their primary food source is human skin cells that we shed naturally. In fact, each of us sheds enough cells each day to feed one million dust mites. And depending on its age, a mattress can harbor up to 10 million dust mites! What you need to know to protect yourself…
Allergies to dust mites are caused not by the mites themselves, but rather by their waste particles and dead body parts. Since we are constantly exposed to dust mites, those of us who have a dust mite allergy are likely to experience year-round symptoms. These can include sneezing…runny nose…red, itchy or watery eyes…stuffy nose…postnasal drip…and cough. (Eczema and asthma symptoms can be triggered or exacerbated by contact with dust mites.) Because dust mite allergy symptoms are so similar to those caused by other common allergens, such as pollen, some patients fail to recognize when the ubiquitous little creatures are the cause of their allergy symptoms or worsening symptoms due to another allergy.
If you have a dust mite allergy: You may notice that your symptoms are worse when you’re in bed or when you first wake up in the morning. That’s because of the high concentration of dust mites in mattresses and bedding. Your symptoms may also flare up when you’re dusting or vacuuming—droppings can easily become airborne…or when the temperature and humidity are higher than usual.
There are a few testing methods that can determine whether you are allergic to dust mites.
The easiest is a skin-prick test: A drop of dust mite antigen is placed on the skin…the doctor lightly scratches your skin through the drop…and then watches to see if you develop redness, swelling or itching within about 20 minutes.
If you cannot have a skin test (some skin conditions and medications make the test unreliable), your doctor might recommend a blood test that looks for antibodies that are produced in response to specific allergens.
As a first step to treating a dust mite allergy, it’s a good idea to follow the strategies below to reduce the load of dust mites in your home. You can’t eliminate them entirely, but reducing their number may be enough to lessen or eliminate symptoms. To start…
• Cover your bedding. Your bed has more dust mites than any other area in the house. What helps: Cover your mattress, box spring, pillows and comforters with dust mite encasings. These encasings work by creating a barrier between you and the dust mites. These products, which are available online, are made of microporous fabrics with a pore size that is too small to be permeated by dust mites.
• Hot-water washes. Once a week, be sure to wash your bedding (sheets, blankets, mattress covers, pillowcases, etc.) in water that’s 130°F or hotter. It will kill mites as well as their eggs.
• Vacuum frequently. Avoid wall-to-wall carpeting since it provides a large area for dust mites to inhabit. Vacuum your rugs, carpeting, drapes and other upholstered or fabric-covered surfaces once a week. A vacuum fitted with a HEPA filter will help prevent allergy-causing particles from getting stirred up in the air you breathe.
• Steam clean. A steam cleaner that produces superheated steam will kill mites and deactivate the
allergy-causing proteins in their droppings. Consider steam cleaning carpets, drapes, upholstery, etc., once or twice a year.
• Keep humidity low. Because dust mites thrive in warm, humid environments, keep your humidity levels below 50%. Use a dehumidifier if necessary during the more humid months of summer. You can place it in the room(s), including the bedroom, where you spend the most time. To keep an eye on the humidity levels in your home, you can purchase a hygrometer online for less than $10.
• Use a HEPA filter air purifier. House “dust” contains copious amounts of skin cells and mites and their droppings, but you can reduce allergy symptoms by using a filtering mechanism to remove airborne particles. Portable HEPA units filter all the air in a room, trapping particles as they pass through. You can also consider a full-house filter for your HVAC system.
If the steps above don’t alleviate your symptoms, you may want to consider either over-the-counter or prescription medications such as antihistamines, nasal sprays or eye drops. If medication—plus environmental control—still doesn’t give you adequate relief from your symptoms, you should consider allergen immunotherapy.
Allergen immunotherapy is the process by which the body builds immunity to allergens such as dust mites. This is accomplished by administering small, incremental doses of dust mite (or other antigens), prompting the immune system to respond by decreasing the body’s reactivity to these substances.
Allergen immunotherapy can be administered by subcutaneous injections (commonly called allergy shots)—given in a doctor’s office (usually weekly in the beginning, then once every few weeks for maintenance) for three to five years.
A newer method is sublingual immunotherapy—allergy drops. Allergy drops are made of the same antigens as allergy shots but are formulated into drops that are placed under the tongue.
Once you have been tested and your allergies have been identified, your doctor can prepare your allergy drops based on your test results. Allergy drops are an effective, safe and convenient way to treat allergy symptoms. Once your drops have been formulated, you take the first dose at your doctor’s office and then continue treatment at home daily for three to five years.
