Everything You Need to Know About Mite and Flea Bites

While they’re not related — in fact, they’re totally different species — mites and fleas are often lumped together in people’s minds because they’re small (sometimes microscopic) bugs that live in groups and that can infest our homes and pets.

In the case of both mites and fleas, many types don’t bite or cause any harm to humans. But there are some varieties with bites that can produce itchy rashes or other skin reactions, allergies, or more serious health complications.

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Here’s a description of each type of bug, and what you need to know about the effects their bites can have on your health.

Mites are arthropods, not insects, and are close cousins with spiders and ticks. (1) Most types of mites feed on other insects or on dead plant and animal material. (Dust mites, for example, feed mostly on dead skin cells.)

But there are a few types that bite or affect people: (2,3)

• Chiggers
• Scabies
• Rat mites
• Bird mites
• Northern fowl mites

Despite what you may have heard or read online, home mite infestations are fairly rare and tend to be much less of an issue than people assume, says Mike Merchant, PhD, a former professor of entomology at Texas A&M University in Dallas. “A lot of the mite stuff on the internet makes it sound like [a mite infestation is] the end of the world, but it’s not,” he says.

Mite bites can cause skin lumps and rashes and, occasionally, more serious reactions, Dr. Merchant says.

Among outdoor mites, the only type that frequently bites people is the chigger. The word “chigger” applies to a particular species of mite that bites during its larval stage of development, and their bite produces an intensely itchy red welt, Merchant explains. “There are not too many other mite problems outdoors,” he adds.

RELATED: Everything You Need to Know About Chigger Bites

When it comes to indoor mites that bite or cause health issues, Merchant says most spring from animal nests. “Some mites will infest the nests of birds and rats and mice, and when they become abundant, they’ll leave that site and sometimes wander into the house and bite people,” he explains. In most cases, the bites of these mites cause an itchy skin rash, which may feature small lumps or pimples.

“The skin might be very itchy or red for a few days, but then that will taper off,” Merchant says of mite bites. Ice and anti-itch creams like hydrocortisone can help control the swelling and itching. But those symptoms should resolve within a week, he says. (Nearly all species of biting house mites cannot live on human beings, and so they don’t “infest people,” he adds.)

There is one outlier: scabies. These mites infest a person’s skin in order to lay eggs and feed, and are usually only passed by direct person-to-person contact. (4) Like other mites, scabies tend to cause an itchy, pimply red rash. But unlike other mites, those rashes will continue to appear unless the person gets medical treatment, usually a prescription-only skin cream or lotion designed to kill scabies.

Dust mites can cause allergies in some people, but these tend to be of the mild, seasonal allergy variety — stuff like a runny nose, sneezing, and itchy eyes. (5) Over-the-counter and prescription allergy meds can help quell dust mite allergies.

RELATED: Everything You Need to Know About Allergies

You don’t need a crazy whole-house treatment or fumigation. You just need to remove the animals and animal nests that are bringing mites into your home, Merchant says. “Everybody always wants a spray to solve these types of mite problems, but the real solution is getting rid of any animals nesting in your home, and animal-proofing your home,” he says. Basically, call in a home pest pro.

The exception here, again, is the scabies mite; in addition to getting medical treatment, you can take steps to eliminate the mites from your household. Scabies mites don’t survive very long when they’re not on human skin. Vacuum your home the day you start treatment and decontaminate your bedding, clothing, and towels by washing these items in hot water and drying on high heat. You can also dry-clean or seal these articles in a plastic bag for at least 72 hours.

When it comes to dust mites, on the other hand, it’s almost impossible to get rid of them all. But frequent home cleaning and dusting, installing HEPA air filters, and buying bedding that can be washed in hot water and that resists dust accumulation can limit allergic reactions.

Fleas are blood-sucking insects that live on mammals — often dogs, cats, or other furry pets. (6) Fleas are brown and wingless. And while they’re small, usually around an eighth of an inch, they’re big enough to see or even feel with your hand, Merchant says.

While they prefer animals to humans, fleas can migrate off pets and onto their owner’s skin. “Usually flea bites are on the lower legs because the fleas get into the carpet and then jump up as we’re walking past,” Merchant explains.

What does a flea bite look like? Like many other types of insect bites, flea bites produce small red bumps that may be itchy and that tend to appear in groups of three or more. Again, ice and hydrocortisone can help relieve symptoms, which tend to be short-lived — a week or less.

Treating pets for fleas is one of the best ways to keep them out of your home, Merchant says. Along with pet treatments, frequent vacuuming and carpet cleaning — along with washing your pet’s bed in hot soapy water — is another way to kill off or remove fleas.

If you don’t have pets but have fleas in your home, Merchant says it’s a good bet that you have some other furry animal living in or under your dwelling. “It’s usually something like a possum or feral cat that’s gotten under the house or into a crawl space,” he says. Call a pest control expert, he advises.

Like all biting or stinging insects, mites and fleas can occasionally cause serious allergic reactions, including problems breathing or a swollen limb or throat. Those symptoms warrant a trip to the emergency room.

Also, anything that causes itchy skin or open sores can allow in bacteria, which could lead to a secondary infection. (7) If you notice swelling, pain, or a mite or flea bite that seems to be getting worse after a day or two, or if you have a fever or other flu-like symptoms, talk to a doctor. Those could all be signs of a bacterial infection.

Finally, both fleas and mites can transmit some potentially serious diseases to humans — namely types of typhus and spotted fever — though these transmissions are very rare. Symptoms include headaches, fever, rashes, and delirium. (8)