Bed Bug Bites vs. Flea Bites: How To Tell the Difference

Bug bites are annoying for multiple reasons, one of which is that it's not always easy to know what kind of insect is to blame for the bites. Many bug bites look and feel similar.

Bed bug bites and flea bites can be tough to tell apart. Health spoke to experts to find out how to differentiate between the two.

What Do Bed Bug Bites Look and Feel Like?

Contrary to popular belief, bed bugs—small, flat, reddish-brown insects—don't just live on mattresses; they can be found in the couch and chair seams, curtain folds, and between cushions. Additionally, bed bugs can live in crevices in walls, John Anthony, MD, a dermatologist at Cleveland Clinic, told Health.

While bed bugs are found mainly in living areas, it's important to know that their presence isn't determined by the cleanliness of the living conditions where they're located.

Bed bugs feed on human blood, but you likely won't notice when they bite. That's because the bugs inject an anesthetic (along with an anticoagulant), so the person doesn't know they're being bitten. "Most people don't feel when the bed bug is biting," said Dr. Anthony. "The bed bugs bite at night, [then] retreat by the time you wake up."

You'll only realize you've been bitten by bed bugs when small marks appear on your skin. While everyone reacts to bed bug bites differently, bed bug bites, in general, look similar to mosquito bites, with a point in the middle (called a punctum) where the actual bite occurred, Tania Elliott, MD, who works in NYU Langone's Department of Infectious Disease, Allergy and Immunology, told Health. Bed bug bites also have the following characteristics:

• Welts appear in a line, often one that zigzags
• Welts are intensely itchy
• Welts are typically located on areas of the body that are exposed when you sleep

It's also worth noting that bed bug bites can have a purplish color, Dr. Anthony said. Specks of blood on your sheets can also indicate bed bugs.

What Do Flea Bites Look and Feel Like?

While bed bugs prefer human blood, fleas are tiny insects that prefer to live on cats and dogs. The presence of pets can help you determine if you're dealing with a flea bite or something else. "People mainly get flea bites from pets, so if you have had no pet exposures, it's less likely to be a flea bite," Dr. Elliott said.

Fleas will resort to humans if they don't have another option; this can happen if your pet has been away from the house for a while and the flea needs another food source.

If your pets are exceptionally itchy, if you see tiny dots on their fur, or if you see tiny insects (which are smaller than bed bugs) on your furniture or other household items, there's a good possibility you have fleas.

Like bed bug bites, flea bites usually appear as small red dots on the body. They can also resemble mosquito bites, Dr. Anthony said. Symptoms of flea bites include:

• Bites that appear as three small bumps together
• Bites that tend to appear on the feet and ankles
• Itchy bites

Risks of Bed Bug Bites and Flea Bites

Bed bugs rarely cause complications, but very rarely some people can be allergic to them. Symptoms of an allergy can include enlarged bite marks, painful swellings at the bite site, and, on rare occasions, anaphylaxis—a potentially life-threatening reaction that requires immediate medical attention.

Flea bites can develop into a rash called papular urticaria, which manifests as itchy welts that can become hot and painful to the touch. You should not scratch flea bites, as fleas carry bacteria that can lead to infections in humans if the bites become open sores. Infected flea bites can become red, painful, swollen, and full of pus; very rarely, bacteria in fleas carry diseases like typhus and plague, though this is very uncommon in the United States.

How to Treat Bug Bites and Flea Bites

The best way to treat bites from bed bugs is to apply a topical corticosteroid ointment and/or take an antihistamine for itchiness.

Flea bites can be treated with 1% hydrocortisone cream and/or antihistamines.

Applying a DEET-based insect repellent can help you ward off flea bites. "The active ingredient in DEET is recommended for effective, long-lasting protection against fleas and other insects," Dr. Elliott said.

However, if you have an infestation, you'll need a professional pest control company to come and treat your home with pesticides.

If you're unsure of what's causing your symptoms, start by calling your primary care provider or dermatologist, who can help identify the causes and advise you on the next steps.