Dust Mite Allergy: Symptoms, Triggers and Treatment
- About 20 million people in the U.S. have a dust mite allergy, and symptoms tend to last all year (AAFA).
- Start with the bed: zippered allergen proof covers on the mattress, box spring and pillows, and bedding washed every week (Mayo Clinic).
- Wash bedding in water of at least 130°F. If your hot water doesn't get that hot, run the bedding through the dryer for 15 minutes above 130°F first, then wash it (Mayo Clinic).
- Keep indoor humidity below 50% with a dehumidifier or air conditioner, and check it with an inexpensive hygrometer (Mayo Clinic).
- Allergy medicine eases symptoms. Allergy shots, the ODACTRA dust mite tablet and ILIT treat the allergy itself.
Dust mite allergy is a reaction to proteins in the droppings and body parts of dust mites, tiny relatives of spiders that live in beds, carpets and upholstered furniture in nearly every home. Because mites live indoors, dust mite allergy symptoms tend to last all year. Common dust mite allergy symptoms include sneezing, a stuffy or runny nose and itchy, watery eyes. The Asthma and Allergy Foundation of America (AAFA) puts the number of people in the U.S. with a dust mite allergy at 20 million.
A few changes at home, starting with your bed, cut down how much allergen you breathe. Allergy medicine eases the symptoms. For longer relief, allergy shots, the dust mite allergy tablet (a form of sublingual immunotherapy, or SLIT) and ILIT (intralymphatic immunotherapy) all treat the allergy itself.
When to get care right away
Dust mites are a common asthma trigger. The ACAAI lists wheezing, chest tightness and shortness of breath among the symptoms dust mite allergy can cause. If you're struggling to breathe or your rescue inhaler isn't helping, call 911 or get emergency care.
Allergy symptoms that wake you at night or limit what you can do also deserve a doctor's visit soon, even if they aren't an emergency.
What are dust mites?
Dust mites aren't insects. They're microscopic arachnids, related to spiders and ticks, according to Britannica. Each one is about a quarter to a third of a millimeter long, the AAFA says, too small to see without magnification. They eat the flakes of skin that people and pets shed, as the ACAAI explains.
They also depend on damp air to hydrate. The ACAAI says mites do best at 75% to 80% humidity and die when it drops below 50%, which makes drier air one of the most useful changes you can make at home.
You don't react to the mites themselves. Cleveland Clinic notes that they can't bite. The allergy is to proteins in their waste and dead bodies, and AAFA warns that this debris can keep causing symptoms for weeks or months after the mites die.
Where dust mites live, and when allergy symptoms are worst
Bedrooms usually have more dust mites than any other room, the AAFA says. Pillows, mattresses, carpet, fabric furniture, curtains and stuffed animals all hold them. They thrive at around 70°F and above, and the AAFA notes they're found in nearly every home except in very dry or high altitude places.
Since mites live indoors year round, the AAAAI describes the resulting symptoms as perennial (year round) allergic rhinitis, as opposed to the seasonal kind pollen causes. Our guide to seasonal allergies by season covers how indoor and outdoor allergens trade places over the year.
Making the bed, dusting and vacuuming all stir allergen into the air you breathe. That's why Mayo Clinic suggests dusting with a damp cloth or mop instead of a dry one.
Air filters can catch some of that allergen while it's in the air. For homes with central heating and air conditioning, Mayo Clinic suggests a furnace filter rated MERV 11 or 12, changed every three months, with the fan left on so it filters the whole house. A freestanding HEPA air purifier only cleans the air in one room, the AAFA notes, so the bedroom is the place for one. The AAFA also says to avoid air cleaners that use heat, ions or ozone.
Dust mite allergy symptoms
The ACAAI lists sneezing, a runny or stuffy nose, red, itchy or teary eyes, coughing and wheezing. The AAFA adds itching in the nose, mouth and ears, and swelling around the eyes.
Dust mite allergy can also trigger asthma and make eczema flare, according to the ACAAI. For people with allergic asthma, the AAFA includes waking at night and lower peak flow readings among the warning signs.
A stuffy nose that never quite clears is easy to mistake for a lingering cold. Itching is one clue that points toward allergies, and our article on allergies or a cold goes through the others.
How dust mite allergy is diagnosed
An allergist can test for dust mite allergy with a skin prick test or a blood test, the ACAAI explains. The AAFA cautions that a positive result alone doesn't prove the allergy, so your allergist will compare it with your symptoms and when they happen. Our guide to allergy skin tests vs. blood tests compares the two.
A confirmed dust mite result also matters for treatment later. Immunotherapy is matched to the specific allergens you react to, so it's the starting point for shots, tablets or ILIT.
How to get rid of dust mites: a simple plan
You can't get every mite out of a home, Mayo Clinic notes, but you can bring the numbers down. Start in the bedroom, where you spend hours every night with your face in a pillow. The allergists' practice parameter on dust mites recommends combining several steps rather than counting on one.
1. Cover the mattress, box spring and pillows. Zippered, allergen proof covers made of tightly woven fabric keep the mites inside from reaching you, Mayo Clinic explains.
2. Wash bedding every week in hot water. Mayo Clinic, the AAFA and the AAAAI all recommend washing sheets, pillowcases and blankets weekly in water of at least 130°F (54.4°C), hot enough to kill the mites. If your hot water doesn't get that hot, Mayo Clinic suggests putting the bedding in the dryer for at least 15 minutes above 130°F to kill the mites first, then washing and drying it as usual to rinse out the allergen. Stuffed toys that can't take hot water can go in the freezer for 24 hours instead.
3. Keep humidity below 50%. A dehumidifier or air conditioner does the job, and a hygrometer from the hardware store tells you whether it's working, according to Mayo Clinic. The AAFA's target range is 30% to 50%.
4. Clear out what holds dust. The ACAAI recommends removing wall to wall carpet, especially in the bedroom, and Mayo Clinic suggests cutting bedroom clutter like knickknacks and stacks of books. Vacuum weekly with a HEPA vacuum. Mayo Clinic notes that vacuuming picks up surface dust but not most of the mites, so it supports the other steps rather than replacing them.
5. Let someone else do the cleaning. If your allergies are severe, Mayo Clinic suggests staying out of the room while someone else vacuums and waiting about two hours before going back in.
Allergy medicine
Antihistamines and steroid nasal sprays are the usual first step, and the ACAAI also lists decongestants. People whose dust mite allergy triggers asthma may need asthma medicines as well, the AAFA notes. Because mites are around all year, many people end up taking something daily with no end date. Medicine treats the symptoms while you take it. It doesn't change the allergy.
Longer term options for dust mite allergy
Allergen immunotherapy trains your immune system to tolerate dust mite allergen instead of reacting to it. The AAFA suggests considering it when home changes and medicine don't give you full relief. There are three forms to compare.
Allergy shots (SCIT) have the longest history. The AAAAI describes a build-up phase of shots once or twice a week for four to six months, then maintenance shots every two to four weeks for three to five years. Our guide to allergy shots explains what that looks like, and How Often Do You Get Allergy Shots? counts the visits.
The dust mite allergy tablet (SLIT) is sublingual immunotherapy: a tablet that dissolves under the tongue once a day at home. The FDA approved one, ODACTRA, for ages 5 through 65. Its label says the first dose is taken in a doctor's office with at least 30 minutes of observation, you'll be prescribed an epinephrine auto injector, and relief may begin within two to three months. Allergy drops for dust mites are a different product, and the AAFA notes they aren't FDA approved.
ILIT (intralymphatic immunotherapy) is the shortest course of the three, and for some people a faster alternative to allergy shots. An allergist injects FDA approved allergen extract into a lymph node, usually near the groin, guided by ultrasound. Injecting it there is an off label use of the extract. A typical course is about three injections over about two months, the schedule used in the trial that established ILIT in 2008 for grass pollen allergy.
Research on ILIT for dust mites is small and mixed. In a 2021 placebo controlled trial in Korea with 32 people allergic to dust mites, cats or dogs, the ILIT group used less daily medicine and reacted less to dust mite on skin testing, but their symptom and quality of life scores weren't better than the placebo group's, and one person in the ILIT group had a severe reaction. An earlier 2017 pilot, mostly in people with dust mite allergy, found symptom scores improved over a year, though it had no placebo group to compare against. If you're considering ILIT for dust mites, ask your doctor how many dust mite patients they've treated and how those patients did.
Our comparison of allergy shots, allergy drops and ILIT puts the three side by side, and the ILIT safety FAQ covers the FDA question in more detail.
When you're ready to talk with an allergist about a faster course of treatment, find an ILIT provider near you.
Frequently Asked Questions
In people allergic to them, dust mites can trigger asthma, and the ACAAI lists wheezing, chest tightness and shortness of breath among the symptoms. Because mites are around all year, Mayo Clinic notes that people may not realize their allergy is making their asthma worse, and it may be a main cause. Asthma that never has an off season is worth raising with your doctor.
No. Cleveland Clinic says dust mites can't bite. The allergy comes from breathing in proteins from their droppings and dead bodies. If you're waking up with itchy bumps on your skin, something else is causing them, and a doctor can help sort out what.
Hot water does. Mayo Clinic says washing bedding in water of at least 130°F (54.4°C) kills the mites and removes the allergen. If your washer's hot water runs cooler, put the bedding in the dryer for at least 15 minutes above 130°F to kill the mites, then wash and dry it as usual to rinse out what's left behind.
Yes. Mayo Clinic says 24 hours in the freezer kills dust mites, though it won't remove the allergen they've already left. That makes freezing a good option for things you can't wash hot, like a stuffed toy or a delicate pillow. Wash the item afterward if the label allows.
Yes, as part of a bigger plan. Zippered covers made of tightly woven fabric keep mites in the mattress and pillows from reaching you, Mayo Clinic explains. The allergists' practice parameter on dust mites strongly recommends them, paired with weekly hot washing and low humidity, because covers on their own are unlikely to ease symptoms.
Yes, if your home runs humid. Dust mites get their water from the air, and the ACAAI says they die when humidity drops below 50%. Mayo Clinic suggests a dehumidifier or air conditioner, plus a hygrometer from the hardware store to check the reading. The AAFA puts the target at 30% to 50%, so the goal is dry air, not desert air.
Allergy medicine works fastest for day to day relief. Immunotherapy changes the allergy itself and takes longer. The ODACTRA label says relief from the dust mite tablet, a form of sublingual immunotherapy (SLIT), may begin within 2 to 3 months of daily use. ILIT has the shortest course of any immunotherapy, about three injections over about two months, though its dust mite research is small. If you'd like to ask an allergist about it, use Find a Provider on OpenAirAllergyNetwork.com to locate an allergist who offers it.
