Dust Mite Allergy
Dust mites and their waste products are one of the most common causes of year-round allergy and asthma.
About 20 million Americans have dust mite allergy.
This fact sheet provides detailed information about the relationship between dust mites and allergies. We hope that this material helps you better understand what dust mites are, how they can trigger an allergic response, and how to manage them. Please keep in mind that this information is not meant to take the place of medical advice from your physician.
After learning from the pediatrician, that 7-year-old Jamie was allergic to things in the dust in their house his mother had to make a few changes to her housekeeping routine. She started in Jamie’s bedroom. She covered his mattress and pillow with special “dust proof” covers and washed his sheets and blankets in hot water every week. She also bought double thickness vacuum cleaner bags and was careful to vacuum the carpet when Jamie wasn’t around. Jamie’s allergy improved remarkably and he was able to reduce his medication and did not need allergy shots after all.
What is a dust mite?
Mites are primitive creatures that have no developed respiratory system and no eyes. Too small to be seen with the naked eye, a dust mite measures about one quarter to one third of a millimeter. Under the microscope, they can be seen as whitish, eight-legged bugs.
A dust mite’s life cycle consists of several stages, from egg to adult. Depending on the species, it takes anywhere from two to five weeks for an adult mite to develop from an egg. Adults may live for two to four months. A female mite lays as many as 100 eggs in her lifetime.
Where are dust mites found?
Dust mites thrive in temperatures of 68-77°F and relative humidity levels of 70-80%. There are at least 13 species of dust mites, all of which are well adapted to the environment inside the average home.
Studies show that more dust mites live in the bedroom than anywhere else in the home.
Dust mites feed primarily on the tiny flakes of human skin that people normally shed each day. An average adult person may shed up to 1.5 grams of skin in a day, an amount that can feed one million dust mites! These flakes of skin work their way deep into the inner layers of furniture, carpets, bedding, and even into stuffed toys — places where mites thrive.
What is dust mite allergy?
Household dust is a mixture of many materials. Dust may contain tiny fibers shed from different fabrics as well as tiny particles of food, plant and insect parts, mold and fungus spores, dander from pet dogs or cats, or feathers from birds. Dust also contains many microscopic mites and their waste products.
The waste products of dust mites — not the mites themselves — are what cause allergic reactions in sensitive individuals. Throughout its short life span, a single dust mite may produce as much as 200 times its body weight in waste products. Dust mite waste contains a protein that is an allergen. An allergen is a substance that provokes an allergic reaction.
What is an allergy?
An allergy is an adverse reaction from an immune response to something that contacts the body, is inhaled, or ingested. The reactions include sneezing, wheezing, cough, itching, skin rashes, stomach pain, diarrhea, or even a fall in blood pressure which can cause dizziness or passing out. With proper management and education, people with allergies can lead healthy, normal lives.
Most dust mites die when exposed to low humidity levels or extreme temperatures. But they leave behind their waste products, which can continue to cause allergic reactions.
How can I find out if I am allergic to dust mites?
Work with your physician or other health care provider to determine if you are allergic to dust mites. Your physician will ask you questions about your symptoms; when you have the symptoms; and about your home, work, or school environment. Your physician may also perform a simple test to determine if you are allergic to dust mites. This can be a blood test or a skin-prick test
What causes dust mites to live and breed?
In most areas of the world, these creatures are in every house, no matter how immaculate. Having dust mites doesn’t mean that your house isn’t clean. But it is true that keeping your home as free of dust as possible can lessen exposure to dust mite waste and reduce the potential for an allergic response for sensitive individuals.
You should know . . . In a warm, humid house, dust mites can easily survive year round.
How can dust mites be managed?
Vacuuming and dusting the house on a frequent basis is not enough to remove dust mites and their waste. Up to 95% of mites may remain after vacuuming because they live deep inside the stuffing of upholstered furniture, mattresses, pillows, carpets, stuffed animals, and toys.
Dust mites are probably impossible to avoid completely. Still, they don’t have to make your life miserable. There are many ways you can change the environment inside your home to reduce your exposure to dust mites and their waste products.
Cover mattresses and pillows. Use a zippered, dust- proof cover. These covers are made of a material with pores too small to let dust mites and their waste products get through. They are referred to as allergen- impermeable. Plastic or vinyl covers are the least expensive, but some people find them uncomfortable. Allergen impermeable covers made of fabric can be purchased from allergy supply companies as well as from many stores selling bedding products.
Launder effectively. Wash sheets, blankets, bedspreads, duvet covers, and comforters every week. Water temperatures of at least 130° F are needed to kill dust mites.
Eliminate dust mite havens. Wherever possible, try to rid the bedroom of all types of materials that mites love. Choose washable bedding and toys. Try to limit the number of stuffed toys and upholstered furniture. Avoid use of wall-to-wall carpeting if possible. Keep pets out of this room as well. Roll up shades are easier to clean than fabric curtains, but if you do have curtains, be sure to wash them often.
• Ideally, someone without dust mite allergy should clean the bedroom. If this is not possible, then wear a filtering mask when dusting or vacuuming. Many drug stores carry these items. Because dusting and vacuuming stir up dust, try to do these chores at a time of day when you can stay out of the bedroom for a while afterward.
• Use a damp cloth for dusting.
• Special vacuum cleaner bags (microfiltration bags)
are available which help reduce the amount of dust, which gets stirred up during vacuuming. Special filters for vacuum cleaners can also help keep mites and mite waste from circulating back into the air. You can buy these bags and filters in large department stores and from an allergy supply company or in some specialty vacuum stores.
• Wash rugs in hot water whenever possible. Cold water leaves up to 10% of mites behind. Dry cleaning kills all mites and is also good for removing dust from fabrics.
Decorate appropriately. Other rooms in your house can be treated similarly to the bedroom. Avoid having wall-to-wall carpeting, if possible. If you do use carpeting, the type with a short, tight pile is less hospitable to mites than the loose pile or shag type. Better still are washable throw rugs over regularly damp-mopped wood, linoleum, or tiled floors.
Reduce household humidity. Use a dehumidifier and/or air conditioner to keep humidity in your home at less than 50%. Reducing humidity is one of the easiest ways to control dust mites.
What is the treatment for dust mite allergy?
Work with your physician to develop a treatment plan that works for you. If you’ve done as much as you can to reduce dust mites in your home and you still are having allergic reactions to house dust mites, you may benefit from getting allergy shots. A dust mite extract can be formulated to help manage your immune system’s response specifically to dust mite allergens. Your physician can help you decide if this is a good option for you.
What kind of physician can treat dust mite allergy?
The internist, family physician, or pediatrician treats many patients for allergies; however, if your allergy symptoms are not under control within 3-6 months, or you have severe persistent allergy symptoms, or if you are having allergic reactions that require emergency treatment, it may be time to see a specialist. Allergists or immunologists are specialists that treat allergies. Those who have completed training in these specialties are usually called either board-certified or board-eligible.
Does health insurance cover treatment for dust mite allergy?
Most health insurance plans provide some level of coverage for allergy patients. Check with your insurance carrier for details. Some things you may want to find out might include:
• Do you need a referral to a specialist from your internist, family physician, or pediatrician?
• Does the insurance carrier offer any patient education or specialized services related to allergies? For example, is there a telephone help line or a home visit program?
• What coverage is offered for pre-existing conditions?
• What medications are not covered by your plan?
(There can sometimes be a delay in approving newly released medications. Your physician may know about them, but your insurance may not cover them yet.)
The information provided in this fact sheet should not be a substitute for seeking responsible, professional medical care.
Reprinted with permission from “Asthma and Allergy Answers,” the patient education library developed by the Asthma and Allergy Foundation of America.