Do Dust Mites Bite?

We get calls from people who wake up with itchy, raised bumps, feel like they barely slept, and want to know one thing: can dust mites bite?

The short answer is no. Dust mites don't bite, and they can't. They simply aren't built for it.

Why Dust Mites Can't Bite You

Dust mites are tiny, about 1/100th of an inch, and too small to see without magnification. They are scavengers that feed on the flakes of skin we shed every day.

A dust mite doesn't have a head the way we do. Instead, the front of its body is a structure called the gnathosoma, which carries its mouthparts. The main ones are the chelicerae, a pair of tiny pincers used to grab and tear food. They are far too small and weak to pierce living skin, which is exactly why dust mites have to eat skin that has already been shed.

No teeth, no biting mouth, no stinger. Dust mites can't bite you, burrow into your skin, or feed on your blood.

So What Is Biting Me?

If you really are being bitten in bed, the most likely culprit is bed bugs. Unlike dust mites, bed bugs feed on human blood, and you can see them with the naked eye. Adults are about the size of an apple seed.

Signs you may have bed bugs:

• Itchy red bumps, often in a line or a small cluster
• Tiny blood smears on your sheets or pillowcases
• Dark or rust-colored spots along mattress seams and bed frames
• Shed skins or live bugs in the seams and crevices of the bed

Not sure? See our guide on what bed bug bites look like. If you have pets, fleas are another possibility. But if you've got bites, don't blame dust mites.

Which leaves the real question: if you're not being bitten, why do you have itchy skin and feel like you didn't sleep?

How Dust Mites Make You Feel Awful

Dust mites cause trouble through allergy, not bites. Their fecal pellets and body fragments contain proteins that many people are allergic to. The best known is Der p 1, a digestive enzyme from the mite's gut.

In an allergic person, the immune system mistakes these harmless proteins for a threat. When you breathe them in, your body produces antibodies against them, and mast cells release histamine and other chemicals that cause inflammation. It's a full-scale defense against something that was never dangerous. That's an allergic reaction.

Dust Mite Allergy Symptoms

The most common symptoms are:

• Sneezing and a runny or stuffy nose
• Itchy, watery eyes
• Coughing, and wheezing or chest tightness in people with asthma
• Itchy skin, eczema flares, and in some people, hives

Hives or bites? Hives (allergic urticaria) are raised, itchy welts that can look a lot like bug bites. The difference is timing: individual hives usually fade within a day while new ones pop up elsewhere, whereas bites tend to stay in the same spot for several days.

Dust mite allergy symptoms are often worst in the morning. Your bed is the favorite spot for dust mites because it's dark, warm, slightly humid, and full of food, so you spend all night breathing their allergens. Congestion can also disrupt your sleep, which is why you may wake up tired and foggy for the first few hours of the day.

What to Do Next

Just because dust mites can't bite you doesn't mean you should put up with them.

Get tested. An allergist can confirm a dust mite allergy with a skin prick test or a blood test. Antihistamines interfere with skin testing, so let the office know about every medication you take. They'll tell you what to stop and when. Blood tests aren't affected by antihistamines.

Skip testing your room. If people sleep in a room, it has dust mites. Instead of trying to confirm they're there, put your energy into reducing their allergens.

Encase your bed. The most commonly recommended first step is to cover the mattress, box spring, and pillows with zippered dust mite covers that block dust mites and their allergens.

Wash bedding weekly. Wash sheets, pillowcases, and blankets every week in warm water, no hotter than 120°F, with an anti-allergen laundry additive. Our post on laundry mistakes that make allergies worse covers how to get it right.

Keep humidity down and clear the clutter. Dust mites thrive in humid air, so aim to keep indoor humidity below 50%. Remove dust-catching knick-knacks from the bedroom.

For more ways to fight the mites, see How to Get Rid of Dust Mites: 6 Highly Effective Methods.

Dust mites can make you miserable, but they can't bite you.

Till next time,
Cheryl

Want the complete picture? Everything on this page is part of our free Practical Guide to Allergy-Free Living, built on allergy expertise we’ve been sharing since 1989 and covering dust mites, pet dander, air quality, laundry, and more. Start at the beginning or jump to the section that matters most to you.