Flea Bites (In Humans)

Fleas are reddish-brown, wingless insects that suck the blood from their host to feed. Source: Andy Crawford / Dorling Kindersley / Getty Images

Fleas are parasitic insects that feed on the blood of mammals and birds. There are an estimated 2,500 species of fleas in the world. The most common flea species in the U.S. is the cat flea, Ctenocephalides felis, which also infests dogs and can bite humans.

Humans can be bitten by so-called "sand fleas," usually found at the beach and in coastal areas. They are not insects, but tiny crustaceans, although their bite is similar to the cat flea's bite. They do not infest homes.

Adult fleas are about 1/12 to 1/8 inch long, wingless, oval, flat from side to side, and dark reddish-brown. They have six long legs and can jump very high and far, about 200 times their body length. Flea larvae are pale white and measure about 3 mm long, resembling tiny worms.

Can fleas live on humans?

Fleas do not generally live on humans, as they are not well-adapted to the temperature of the human body, which is lower than that of their preferred animal hosts. Human blood may supply nutrients for fleas, but human skin lacks the hair density of animal hosts, such as cats and dogs. It’s easier for fleas to live and reproduce in the protected habitat that animal fur offers.

Do fleas bite in a line?

Flea bites can appear in a straight line or a cluster of several bites, which most commonly occur on the legs, feet, calves and ankles.

When fleas bite, they inject saliva into the skin, causing itching and irritation. Flea bites can appear as small red bumps surrounded by reddened skin, creating a halo appearance.

Flea bites appear as small red dots.

What do flea bites look like? Flea bites look like small red dots. These spots often occur in two to three groups or clusters with redness around them and sometimes a light halo. They tend to bite humans around the feet, ankles, and lower legs.

For people who are allergic to flea bites, there can be larger areas of redness and small pimple-like bumps. The redness can last from a few hours to several days, depending on an individual's reaction, and how much (or little) the bites are scratched.

Symptoms of flea bites on humans that will occur immediately after being bitten include:

• Red spots with a halo
• Itching
• Hives
• Rash (characterized by small clusters of bumps)
• Swelling around the bite

What does it mean if flea bites turn purple?

Flea bites that turn purple suggest bruising or a serious allergic reaction that results in inflammation and discoloration, which may include reddish hues. The purple tint might be caused by the rupture of blood vessels under the skin, which can result from scratching itchy bites.

Are flea bites harmful to humans?

Flea bites are normally harmless to humans, causing only mild symptoms, such as itching and redness. However, prolonged scratching of the bites can cause secondary skin infections, which may necessitate treatment. Individuals may have allergic responses to flea bites, which can be severe and involve symptoms such as swelling and acute itching.

Moreover, fleas can carry and transmit illnesses to humans, including typhus and plague, which are major health risks, as well as tapeworms. While such transmissions are uncommon, they emphasize the possible health hazards linked to flea infestations.

Although flea bites are usually not dangerous, they can cause pain and other health problems if not treated correctly. Keeping pets flea-treated and living in clean environments are effective preventive methods. If flea bites are suspected of causing more serious symptoms or diseases, it is crucial to see a doctor.

Some people are more sensitive to flea bites and can have allergic reactions. Symptoms of a severe allergic reaction to flea bites include:

• Difficulty breathing (shortness of breath or wheezing)
• Swelling of the lips or tongue
• Dizziness
• Nausea
• Chest pain

Severe allergic reactions to flea bites with any of  the symptoms described above can be a medical emergency, so call 911 or get to a hospital's emergency department immediately.

Do flea bites itch? Is it bad to scratch them?

Regardless of how much they itch, try not to scratch flea bites. Flea bites can itch intensely and can develop a secondary infection if scratched.

Symptoms of infection of the skin include:

• Redness
• Pain
• Fever
• Red streaking on extremities
• Swollen lymph nodes

If your dermatologist suspects a flea bite, they will inquire about your living conditions and recent exposure after your skin examination. There is no laboratory test to confirm that fleas are the causal agent of these rashes.

To establish if a bite is from a flea, you can look for the following characteristics:

• Appearance: Flea bites often cause tiny, red, itchy bumps on the skin. They frequently feature a core red spot surrounded by a red halo, giving them a unique look.
• Location: Fleas typically bite on the lower legs, particularly around the ankles and feet, as they often jump from the ground or carpet onto their host. However, flea bites can occur anywhere on the body, especially in skin folds or locations where clothing fits tightly against the skin.
• Pattern: Flea bites frequently appear as clusters or lines, as a single flea can bite many times in the same region. This linear pattern is often called "breakfast, lunch and dinner" bites.
• Symptoms: Flea bites are usually very itchy and might cause burning sensations. Some people may have more serious responses, such as swelling, hives or trouble breathing, which might be an allergic reaction.
• Presence of fleas: If you suspect flea bites, inspect your pets and your home for evidence of a flea infestation. Look for little, brown, wingless insects jumping on your dogs, furniture and rugs. You may also detect flea dirt, which might appear as small black specks that become reddish-brown when wet.

If you have pets, check them for fleas. If your pet is scratching excessively or you discover signs of fleas on your pet, flea bites are likely to be the source of your symptoms.

A consultation with a healthcare professional or a dermatologist can be beneficial for correct diagnosis and treatment suggestions.

Both flea bites and bed bug bites itch and can cause allergic reactions.

Flea bites and bed bug bites appear similar, but they are not the same.>

• Bed bug bites often look like mosquito bites. They can be red and firm, and there may be some slight swelling around the bite. Flea bites look like small clusters of red spots.
• Bed bug bites often appear in linear rows and can appear anywhere on the body, whereas flea bites tend to be located in clusters often on the feet and ankles.
• Bed bugs are nocturnal, and like to make their home in your mattress, so bites from these insects usually occur at night when you are sleeping. Fleas are also nocturnal but tend to cling to pets, and are found on furniture, drapery, and carpeting.
• Bed bug bites may take several days to appear and will start to itch gradually, whereas flea bites start to itch immediately and become swollen and red within an hour after the bite.
• Both flea bites and bed bug bites itch and can cause allergic reactions.

Flea bites and mosquito bites have some distinct differences:

• Appearance: Flea bites often present as little, red, itchy pimples with a center red area surrounded by a red halo, while mosquito bites typically appear as bloated, white and irritating pimples that vary in size.
• Location: Fleas usually bite the lower legs, ankles and feet as they jump from the ground or carpet; however, they can bite anywhere on the body, particularly in skin folds or locations where clothing is tight against the skin. Mosquitoes can bite on any exposed body parts although they favor places with thin skin, such as the arms, legs and back of the neck.
• Pattern: A single flea can bite many times in the same region, resulting in a linear pattern known as "breakfast, lunch and dinner" bites. However, mosquito bites are often isolated and do not follow a precise pattern. That’s because mosquitoes bite once and then move on.
• Symptoms: Flea bites are extremely irritating and can create a burning sensation. Some people may have more severe responses, including edema, hives or trouble breathing. Mosquito bites, on the other hand, produce mild to severe irritation and might result in regional edema and redness. In rare cases, some people may have more severe allergic responses.
• Timing: Flea bites can occur at any time although they are more common when there is an infestation in the home or on a pet. Mosquito bites are more common in the warmer months and more likely to occur outside, especially around dawn and dusk, when mosquitoes are most active.

If you are unclear if a bite was caused by a flea, mosquito or another bug, visit a healthcare provider for an accurate diagnosis and treatment.

To help alleviate symptoms and promote healing, follow the steps below:

• Wash the bite area: Use mild soap and warm water to limit the risk of infection and remove any remaining flea saliva, which can cause irritation.
• Use a cold compress: Place a cool, moist cloth or an ice pack on the affected area for about 10 minutes at a time to reduce swelling, numbness and itching.
• Use over-the-counter treatments: To reduce itching and irritation, apply calamine lotion or 1% hydrocortisone cream to the bite. You may also take oral antihistamines, such as Benadryl (diphenhydramine). If you have an allergic reaction, see a doctor. You may be prescribed a stronger antihistamine such as hydroxyzine (Vistaril, Atarax).
• Avoid scratching: Scratching flea bites can cause further discomfort and increase the risk of bacterial infection. Keep your fingernails short and clean, and resist the impulse to scratch.
• Look for signs of infection: See a doctor If you have increasing pain, swelling, redness, warmth or discharge around the bite, or if you get a fever. These signs could indicate a secondary infection.
• Treat your pets and clean your surroundings: To avoid further flea bites, treat your pets with suitable flea-control products. Also, thoroughly clean your home, including your carpets, bedding and furniture using flea-control pesticides.

Usually, flea bites heal on their own within a few days to a week. However, if you have serious symptoms or indications of an allergic response, such as trouble breathing or widespread hives, seek medical attention right away.

Natural and home remedies to soothe or relieve itching from flea bites include:

• Wrap ice packs (or frozen vegetables) in a towel and apply them to the skin to relieve swelling, and numb the area.
• Aloe Vera may ease redness and swelling.
• Witch hazel can help with itching.
• Rubbing alcohol can be used to dry the bites.
• White vinegar (dilute 1 part vinegar with 1 part water) can provide temporary relief.
• Tea tree oil can relieve itching.
• Cool used teabags in the freezer and apply them to the bite to relieve inflammation.

Avoid scratching the flea bites because you can create an open wound that will let in bacteria, and can lead to infection.

The main symptom of flea bites is itching, which can be treated with over-the-counter (OTC) anti-itch creams, lotions, or ointments.

• Wash the area first to lessen the chances of infection.
• Apply an anti-itch topical medication such as calamine lotion (Caladryl), hydrocortisone (Cortaid, Cortizone), or diphenhydramine (Benadryl Itch Stopping Gel).

If the itching is bothersome, an oral antihistamine such as diphenhydramine (Benadryl) may help. If you have an allergic reaction, see a doctor. You may be prescribed a stronger antihistamine.

Infection and disease can result from flea bites. Infection usually occurs because of scratching the bites. Bacterial and other debris can be present under the fingernails, and if a person vigorously scratches a fleabite, they may cause the rash to become an open wound for bacteria to enter.

Fleas also can be a public health threat because they can transmit several diseases to both humans and animals.

Since most flea bites are due to fleas brought into the home by pets, the best way to prevent being bitten is to prevent the fleas from getting on your pets.

• Keep your pets away from animals you know have had fleas recently.
• Keep your pets out of difficult-to-treat places such as under decks or sheds.
• Mow your lawn frequently and keep the grass short.
• Use a flea comb to check your pet's fur for fleas.
• Keep pet bedding clean and wash it in hot water.
• Vacuum carpets, rugs, and upholstered furniture frequently, especially in areas where pets sleep, under beds, sofas, and behind furniture.
• Dust furniture and dry clean curtains and upholstery.
• Use flea preventive medicine on your pet once a month (for example, Advantage, Advantix, Frontline, Revolution, Sentinel, and others). Talk to your veterinarian about the right product for your dog or cat.

If you catch fleas on pets or in your home early it is much easier to get rid of them before they spread throughout your home.

To prevent bites from sand fleas if you are on the beach:

• Avoid the beach in the early morning and late afternoon, when sand fleas feed.
• Use lounges or chairs rather than a towel or blanket on the sand.
• Wear closed shoes and socks when walking on the beach.
• Use insect repellant with DEET.
• Stay away from seaweed, a favorite food of sand fleas.

While most home flea infestations occur in homes with pets, fleas can infest homes without pets as well. This may happen in several scenarios.

• If you recently moved into a home where previous owners had pets with fleas, and they were not properly eradicated, you may find yourself with a flea infestation.
• Used furniture may come infested with fleas.
• Neighborhood dogs or cats that have fleas may hang out near your home
• Pests such as rats or mice, or wild animals such as opossums, raccoons, squirrels, and skunks also can carry fleas and bring them into your home.

What public places may have fleas?

• A common public place where fleas may be found is in dog parks. They also may be found in large natural parks that are home to wild animals such as opossums, raccoons, squirrels, and skunks that can carry fleas.

How do you check your house for fleas?

One of the first ways people notice they have a flea infestation is when their dogs or cats start scratching, biting, or licking themselves excessively. You can use a flea comb to check your pet's fur for fleas and flea feces. Flea feces on your pet may look like dot-like insects or flecks of dirt or pepper.

Once fleas have gotten onto pets it does not take long to spread through the household. Once they have infested the home, you may notice fleas hopping on your carpet, furniture, or drapery.

If you suspect that your pet or home may have a flea infestation you can test the dark specks to see if it is flea feces. Moisten the suspected flea feces, and if it turns red or maroon, it is flea feces. (Flea feces is comprised of dried blood.) Another quick way to help you check for a flea infestation is to wear long white socks. Fleas like to jump on human feet, ankles, and lower legs. The insects are dark reddish-brown, and if they jump on you while you wear white socks they will be easier to see.

Can fleas live in your bed?

Fleas may survive in your bed, but it is not their preferred environment. Fleas are more likely to be found on pets, such as dogs and cats. However, if your pet sleeps on your bed or spends a lot of time in your bedroom, fleas can jump from the animal to your bed. Once they are on your bed, they can hide in bedding fibers, as fleas thrive in warm, damp conditions.

Getting rid of fleas is a multi-pronged approach. Some natural solutions may help repel fleas, however, if you have an infestation it is probably best to consult a pest-removal specialist to thoroughly rid your home of fleas, and consult your veterinarian to make sure your pets are flea-free.

Once you have gotten rid of fleas, you can use some natural remedies to prevent them from returning.

1. Treat areas of the home with antimicrobial solutions such as tea tree oil, garlic spray, or diatomaceous earth powder.
2. A few drops of tea tree oil may be added to bath products, or it may be used as spray-on bedding, upholstery, carpets, and other fabrics.
3. Essential oils can be used to make a homemade flea-repellent spray. Common oils used include eucalyptus, peppermint, tea tree, rosewood, cedar, citrus, or lemongrass. Mix with water and put in a spray bottle.
4. Use homemade flea traps to help get rid of fleas. In a bowl, add equal amounts of hot water and liquid hand soap, and place the bowl at the foot of your bed with a small lamp nearby. The fleas are attracted to the warmth of the light and will fall into the trap and drown.
5. Before you vacuum, sprinkle diatomaceous earth powder and Borax powder on carpets, rugs, and flooring. Borax can be irritating to the skin and eyes, so keep away from children.
6. Eucalyptus trees are known to be flea-repellent and can be planted in the yard.

Flea bombs (foggers) do not soak into carpets well, where flea larvae live. Because of this, most pest control specialists do not recommend flea bombs because they do not consider them to be effective.

Some natural remedies that may help repel fleas in pets include:

1. Add small amounts of Brewer's yeast and apple cider vinegar to your pet's drinking water to help repel fleas.
2. Diluted apple cider vinegar may also be used as a final rinse for pets after bathing.
3. Herbal shampoos to bathe your pet(s) include eucalyptus, lavender, geranium, lemon, or tea tree.
4. Garlic added to your pet's food may help repel fleas.

Talk to your vet about ways to keep your dogs and cats free from fleas. Before using any home or natural flea preventive/repellent remedy on your pets, consult with your vet. Some remedies work well for some pets and not others, and some pets may have unwanted reactions to these items. The amount of any herb oil or other product used for a pet may vary depending on their size, weight, age, breed, and overall health. It is always best to consult with your veterinarian to make sure the products and amounts you use are safe for your cats and dogs.

Flea bites can transfer diseases to people but not as often as other vectors, such as ticks and mosquitoes. Here are some diseases that fleas may spread:

• Plague: Fleas, mostly rodent fleas, can spread the bacteria Yersinia pestis, which causes plague — a disease responsible for multiple historical pandemics. Plague can take several forms, including bubonic, pneumonic and septicemic.
• Murine typhus: This is caused by Rickettsia typhi and spread by rat fleas. Symptoms include fever, headache and rash. Although it’s rarely deadly, it must be treated with antibiotics.
• Tungiasis: This is caused by the sand flea Tunga penetrans, which burrows into the skin of hosts, including humans. It is more of an infestation than a transmitted disease, yet it may cause serious skin irritation and infections.
• Tapeworm infection: Fleas may transmit tapeworms to people; however, this is more prevalent in pets, such as dogs and cats. Humans can become infected by mistakenly ingesting fleas that contain tapeworm larvae.
• Cat scratch disease (CSD): While fleas can’t directly transfer the bacteria Bartonella henselae, which causes CSD, fleas may spread it among cats. Humans can get CSD through scratching or biting diseased cats.

It is important to reduce the risk of diseases by managing flea populations in both household and wild environments. Regular flea treatments for pets and keeping living environments clean are excellent preventative measures.