Do dust mites bite?
Dust mite bites are a myth, a mix-up, a misunderstanding. The tiny bugs just aren’t into you that way. They're scavengers not hunters. Read on to find out what that means and why there’s so much confusion about it. And how, even though dust mites don’t bite, they can still cause itchy allergic reactions.
Why would dust mites bite?
That’s a good question. Other bugs we love to hate – horse flies, fleas, lice, ticks, bed bugs, midges and mosquitos – feed on fresh human blood. That’s why they bite. But dust mites are scavengers. Their favourite food is flakes of dead skin you’ve already shed.
In fact dust mites couldn’t bite you even if they wanted to. Under the microscope most insects look like monsters in a horror movie. Dust mites too. But if you’re brave enough to examine these cousins of the spider you’ll see jaws for grabbing hold of tasty morsels of dead skin. Biting insects, on the other hand, tend to have long mouthparts designed to pierce and suck.
How did the myth of the dust mite bite start?
Well, dust mites may not bite but other mites do. And they’ve given the whole family a bad name. Without going into too much itchy detail, there are biting mites that prefer mice and rats or birds but will hop onto humans if they have to. And there’s another mite that can give you a skin condition called scabies. But this is not, repeat NOT, the house dust mite.
Are dust mites harmless?
Yes, in that you don’t have to worry about dust mite bites. But the eating habits of these bugs do have unwelcome effects. Dust mites follow the food and what better place to find dead skin than where we live. People shed dead skin cells all the time – and up to 40,000 a day. It’s a large part of the normal content of household dust. So, of course, there are thousands of tiny dust mites living in every home, even yours.
Dust mites bite the dead skin (not you, as we’ve said) into pieces to eat. Then they poo. Each one produces as much as 200 times its body weight in its lifetime in waste; mostly faecal matter, plus bits of outgrown shell. The tiny particles measure about 20-25 μm (microns), roughly the same as a pollen grain. And they’re one of the most common causes of allergy.
So it’s not dust mite bites that make me itch?
That’s right. The tiny bugs can cause dust mite rash but it’s not because they bite. Skin rashes and eczema (atopic dermatitis) can be reactions to dust mites. Breathing in the waste particles can give you something like hay fever (allergic rhinitis) except symptoms happen at any time of year. Turning on the central heating in the autumn tends to be a sneezy moment. It blows settled dust into the air and dust mite allergens with it.
Here’s a checklist of common symptoms of dust mite allergies:
- Gritty, itchy or watering eyes
- Runny or stuffy nose
- Dry or sore throat
- Shortness of breath
- Skin reactions
Dust mite allergy hotspots
Dust mites are opportunistic and you’ll find them wherever human beings spend most time indoors (if the conditions are right; more about that later). Any room with upholstered furniture, carpets, rugs and curtains is their perfect habitat. Dust mites are common in public places like cinemas or trains but our homes are usually the real hotspots.
You’ll find the biggest concentration of dust mites in your bedroom. They live on bed linen and in mattresses, duvets, blankets and pillows; one sort of dust mite particularly likes feathers. Allergens can build up here and cause problems at night, often affecting your quality of sleep. Soft toys also tend to store up dust mite allergens, especially if children take them to bed every night.
And this is a clue to a possible culprit for those dust mite bites that aren’t from dust mites. Bed bugs love your bedroom too.
Dust mite bites could be from bed bugs
Bed bugs usually live within 2.4m of where people sleep. As well as your bedroom at home, they love youth hostels, hotels, dorm rooms and cruise ships, but also trains or buses. So that’s where you might get bed bug bites that you think is a dust mite rash.
Bed bugs and dust mites have much in common. Here’s how you can tell them apart.
|Dust mites||Bed bugs|
|How big are they?||0.3mm long; too small to see with the naked eye usually||Some are a tiny 1mm but they can be up to 6mm long|
|Favourite food?||Dead skin shed by humans and their pets||Fresh blood taken while you’re asleep|
|Do they bite?||
Dust mite bites are a myth
Bed bug bites are itchy red bumps like mosquito or flea bites. They often appear in a row on parts of your body that aren’t under the covers while you’re asleep at night
|Can they cause allergy symptoms?||Dust mites are one of the most common causes of allergy – their tiny particles of waste trigger the allergic reaction, usually when you breathe them in||Some people are allergic to bed bugs; the bite turns painful and swollen and you may get hives or blisters. In rare cases the allergic reaction can be severe|
|Clues that bugs are in my home?||There’s nothing to see. You just know they’re there||Old bits of discarded shell, bed bugs in your sheets and along mattress seams, rusty coloured poo marks, a sweet stale smell|
|How do I get rid of the pests?||Regular rigorous cleaning and other good habits at home can help (more below)||Call pest control|
Dust mite allergy: getting a diagnosis
So you’ve got a rash that isn’t from dust mite bites. Your nose is blocked a lot of the time. And you’ve jotted down some other symptoms in your allergy diary. And you think it’s time to talk to your doctor or an allergist.
The first thing they’re likely to suggest is allergy testing to see if dust mites could be a trigger. A skin prick test means putting a drop of liquid containing the allergen onto your skin, scratching it gently and checking for a reaction. Or you may have an allergy blood test. Both need interpreting by your doctor, alongside your medical history and your family’s, plus a detailed account of your symptoms.
What’s the treatment for dust mite allergies?
Antihistamines and corticosteroids can both ease dust mite allergy symptoms. Antihistamines work by blocking the chemical histamine which the body releases when it comes into contact with dust mite allergens.
Corticosteroids are anti-inflammatory. These medicines may help calm the allergic rash that isn’t dust mite bites, soothe your eyes and control the irritation in your nose. Decongestants can also help with your blocked nose – to be taken only for a limited time. Many allergy medications are available over the counter but you will need a prescription for stronger versions.
If you find your symptoms are still troublesome, what next? Well there may be specialist treatments available as an alternative. Immunotherapy tackles the cause of your allergy. Repeated tiny doses of the allergen gradually get your immune system used to it. The treatment takes a long time but it should reduce the need for symptom relieving medications.
How can I get rid of dust mites?
If your “dust mite bites” are actually from a bed bug infestation it might be best to call pest control. But controlling dust mites is a DIY job. Try these tips. They may help lessen or prevent allergic reactions to dust mites.
Make your home dust mite unfriendly: Apart from a ready source of food, dust mites like living with you because your home is warm and relatively humid. These bugs don’t drink; they survive by absorbing water from the environment through their front legs. It’s also why dust mites are so content in your bedroom; the cosy covers trap sweat and moisture from your breath.
Dust mites thrive at 75% humidity and will still grow, though more slowly, as long as it’s above 50%. At that sort of level they will also be far less active. Below 50% dust mites dry out and die. So think about getting a dehumidifier for your home. And dial the temperature down to below 20C to help prevent dust mites.
Reclaim your bed(room): Use special mattress and pillow covers that keep out dust mites and their allergenic poo. Wash bedding in hot water every week. Ideally that means at 60C but a lower temperature can also get rid of a lot of the bugs. The tumble dryer is super useful for tackling bulky bedding you can’t easily wash. Duvets and quilts should go in for an hour. Blankets only need 10 minutes.
Move dust traps out of your bedroom. That includes the dirty laundry basket and your pets and their beds.
Learn to love housework: Vacuum at least once a week, ideally twice, including any fabric-covered furniture. Fitting your vacuum cleaner with HEPA filters will help trap waste particles in the dust collector. Damp cloths do that better than a duster too.
The smallest movement can send up a cloud of allergens. You’ve probably seen the whirling motes in a shaft of sunlight after you change the bed, plump a cushion or vacuum. The particles then take 20-30 minutes to settle back down again. Best to wear a mask while you’re cleaning so as not to stir up dust mite allergy symptoms too.
Dust mite bites: nothing to be scared of
Dust mite allergies aren’t trivial, of course. Which is why it’s a good idea to check out possible allergy symptoms with your doctor or an allergist. But dust mites themselves are harmless. They don’t buzz in our ear. Or scuttle about on our bodies. Or dive bomb us from a great height at night. And whatever you’ve heard, dust mites don’t bite humans.
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