Dust Mites May Be Causing Your Winter Allergies
By Michael Steven Blaiss, MD, Special to Everyday Health
Why am I sneezing so much this winter – and why does my nose run all the time? Why do I wake up every morning with nasal congestion? Is it a cold that’s lasting for weeks? If you’ve been asking yourself these questions, it’s likely you have winter allergies.
We usually think of allergies in the spring when the trees and grasses produce pollen, or in the fall with ragweed pollen in the air. But allergies can occur year round. House dust mites are a common trigger of winter allergies. The good news is there are many ways to help reduce the effect of dust mites and feel better.
What Are Dust Mites?
Dust mites are 8-legged bugs related to the spider family, and they’re too small to be seen by the naked eye. They are sightless and live off discarded dead skin cells. In fact, the two major dust mite species found in the United States get their name, Dermatophagoides, from the Latin meaning “skin eating.” Luckily, they are not parasites, and they don’t bite or sting. It is the proteins in the bodies of the mites and their droppings that cause allergy in people.
Dust mites have specific environmental requirements for growth. Ideally, they need temperatures above 70 degrees F, and relative humidity above 70 percent. Adult mites have a life expectancy of between 4 and 6 weeks, during which time females can lay between 40 and 80 eggs. With this rapid reproductive turnover, mites can colonize a new home within a year.
Most homes in this country have dust mites no matter how much they are cleaned. The highest levels of mites in homes are found in pillows, mattresses, sofas, carpet and other soft furnishings. These objects can trap and accumulate skin dander and moisture, leading to optimal growth of the mites. Studies have shown that a typical mattress may have 100,000 to 10 million mites inside. Ten percent of the weight of a two-year-old pillow can be composed of dead mites and their droppings.
How do you know if you have a dust mite allergy? If you have sneezing, nasal congestion, watery eyes, and wheezing on a year-round basis, especially outside the pollen seasons, dust mites may be the culprit. It is estimated that 20 million Americans suffer from a dust mite allergy. Your allergist can do either an allergy skin test or a blood test to confirm if dust mites are causing your symptoms.
Fighting Dust Mite Allergies
What can you do? First, there are ways to reduce your exposure. Concentrating on the bedroom is most important, as people spend more time in their bedrooms over a 24-hour period than any other room in the house. If possible, all carpeting and drapes should be removed. Levels of mites in the bedroom can be reduced by using small area rugs, blinds or window shades, all of which can be easily cleaned.
Enclose the mattress and pillow in mite-proof casing. These covers are made of a material with openings too small to let dust mites and their droppings get through. All bedding should be washed weekly with hot water. Unfortunately, cold-water washing will not kill dust mites.
In some cases, the use of a dehumidifier in the bedroom can help, as dust mites can’t grow with humidity below 50 percent. If your child has a dust mite allergy, try to limit the number of stuffed animals in their bed. Freezing stuffed animals for 24 hours weekly will also kill dust mites. Vacuum at least weekly using a double-layer bag or HEPA filter on the vacuum to prevent dust mites from circulating back into the air.
Medications can help control symptoms. There are several over-the-counter treatments such as non-sedating antihistamines and intranasal corticosteroidswhich may give some relief to your nose and eyes. If these treatments are not effective, or if every time you stop using them your symptoms return, you may want to see a board-certified allergist for further management.
There are excellent prescription treatments, and you may be a candidate for immunotherapy for allergies. Allergy shots are the only way to reduce sensitivity over time to dust mites, and can lead to lasting relief of symptoms after the treatment is stopped. Remember: You don’t have to be miserable all winter with dust mite allergies. Relief is available.
Michael Steven Blaiss, MD, is clinical professor of pediatrics at the Medical College of Georgia in Augusta and executive medical director of the American College of Allergy, Asthma, and Immunology.