Flea bites are small, discolored bumps on your skin that come from fleas feeding on your blood. Fleas are small insects known as vectors (living things that carry diseases between animals and humans). Vectors often carry infections through blood.
Flea bites are small, discolored bumps on your skin that come from a flea feeding on your blood.
Fleas are tiny, wingless insects. They are dark brown or black and have flat bodies. They have six legs, strong claws on the bottoms of their legs that allow them to hold onto a host and mouthparts that pierce your skin and feed on your blood. Their hind legs are longer and stronger than their legs in the middle and the front, allowing them to jump over 12 inches.
There are more than 2,500 flea species in the world and more than 300 species in the United States.
Flea bites rarely cause any lasting harm. They cause mild annoyance and irritation for a short period. However, flea bites can be dangerous because they may spread diseases that can be serious or even fatal.
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Fleas are most active when the weather is warm. Outside, fleas prefer cool, damp areas with a lot of shade. They live around trees, leaves, tall grass and shrubs. Fleas hop onto animals when they walk by these areas.
On dogs, cats and other animals, fleas live around the ears, neck, back and belly (abdomen). Once inside your home, fleas may jump off an infested animal and hide. They often hide in carpet, furniture, bedding and cracks in the floor.
Male and female fleas feed on blood. Female fleas lay eggs after feeding on blood. In some flea species, especially the species that commonly bother dogs and cats, baby fleas (larvae) feed on blood-rich adult flea poop (feces). Flea poop is also called flea dirt.
Fleas bite humans. However, the flea species that commonly bother dogs and cats don’t live on humans. Dogs and cats have much more hair than humans. Fleas like animals with a lot of fur because fur allows them to hide easily.
Fleas have strong claws on the ends of their legs that they use to hold onto a host. Their mouthparts include a tiny needle (proboscis) that pierces your skin, sucks your blood and secretes saliva into your bloodstream.
When a flea secretes saliva into your bloodstream, your body registers the saliva as an allergen. Your immune system then sends the chemical histamine to the area where the flea bit you to remove the allergen from your body. Histamine is what causes your flea bites to itch and swell. Most people have a flea bite allergy.
Fleas prefer to bite animals. If there isn’t an animal in the area, fleas will bite anyone. The following factors attract fleas:
After a flea bites you, a small, discolored bump forms. A discolored ring or halo may appear around the bite. Flea bites may appear in a straight line or a cluster of many bites.
Flea bites most commonly occur on your legs, especially your feet, calves and ankles. Flea bites rarely appear above your knee, unless you spend a lot of time sitting or lying down.
Male and female fleas bite. They feed on your blood as part of their diet. Female fleas lay eggs after feeding on blood. In some flea species, flea babies feed on adult flea poop, which contains blood.
The symptoms of a flea bite vary. If the flea has a disease or an allergic reaction occurs, the symptoms may be more severe.
Common symptoms include:
More severe symptoms can include:
Flea bites are slightly more unique than other common insect bites. After a flea bites you, a small, discolored bump typically forms. A discolored ring may form around the bite. Flea bites don’t swell to the size of mosquito bites.
Flea bites are also unique because of their bite pattern and location. Flea bites often appear in a straight line or a cluster. Fleas are more likely to bite you on your legs, especially your feet, calves and ankles.
It’s important to examine your pets. If your pets are scratching more than normal and restless, it’s a good idea to check them for fleas. If your pet has fleas and you have bites on your legs, you likely have flea bites.
Flea bites typically don’t need treatment. Over-the-counter anti-itch creams or ointments and antihistamines can relieve itchy skin and discomfort. However, see your healthcare provider if more severe symptoms develop after a bite (allergic reaction, fever, headache or body aches).
Don’t scratch your flea bites. You risk breaking your skin and exposing yourself to infection. If you accidentally break your skin, keep the area clean by washing it with soap and water and covering your flea bites with a bandage. Talk to your healthcare provider if you have an infected flea bite.
Flea bites only last a few days. However, there are many over-the-counter products or home remedies that can stop flea bites from itching.
Home remedies are safe for most people. However, it’s a good idea to check with your healthcare provider before trying some of the following options to get rid of your flea bites. You may be at risk of developing an allergic reaction on your skin.
To stop flea bites, you must get rid of the fleas. Fleas are more likely to bite your pet. Check your pet for fleas around their ears, neck, back, and belly. Part your pet’s fur and look around its skin. If you find fleas, here are some removal options:
Like fleas, bed bugs feed off your blood and secrete saliva into your bloodstream. Bed bug bites look similar to flea bites. However, bed bug bites often exhibit a distinct line or zigzag pattern. Bed bugs are active at night, and they’ll bite your exposed skin while you’re sleeping, including your face, hands, arms, feet and legs.
Mosquitos are small, flying insects. They also feed off your blood and secrete saliva into your bloodstream. Mosquito bites look a little different than flea bites. After a mosquito bites you, a small, raised bump forms. The raised bump may change colors, and you can sometimes see a small, dark spot in the center. The dark spot is where the bite occurred.
Fleas spread disease through their bites. Fleas are vectors (living things that carry diseases between animals and humans). Vectors often carry infections through blood. Many of the creatures classified as vectors are bloodsuckers. Other vectors include ticks, mosquitoes and sandflies.
In rare cases, fleas can spread tapeworms and other parasites to animals and people. Parasites can spread if a person or animal were to swallow an infected flea accidentally. In houses with a flea infestation, young children are more likely to get a parasite than adults. Young children spend more time on the floor, and fleas like to hide in carpets and cracks.
Fleas sometimes carry diseases that can infect humans. Some of those diseases include:
Plague most commonly affects small rodents in Africa, Asia, North America and South America. Most human cases of plague in the United States occur in the western part of the country, especially in rural New Mexico, Arizona, Colorado, Utah, California, Oregon and Nevada. Infected fleas can transmit plague to humans. Humans can also get plague after handling an infected animal. Symptoms of plague include:
Endemic murine typhus
Endemic murine typhus commonly occurs in warm coastal areas in tropical and subtropical regions. Most cases in the United States occur in southern California and Texas. Infected fleas transmit endemic murine typhus to humans through flea poop. Infected flea poop enters your body through broken skin — typically from scratching a flea bite — or by inhaling it through your mouth or nose. Symptoms of endemic murine typhus include:
Cat Scratch Disease (CSD)
CSD commonly occurs throughout the world. In moderate climates, more cases occur during the fall and winter seasons. In tropical climates, cases occur throughout the year. Fleas pass on the bacteria _Bartonella _to cats. Fleas can sometimes pass the bacteria to dogs or other animals. Infected cats also pass the bacteria during fights with other cats. Cats — especially kittens — pass the infection to humans through a bite or scratch. Symptoms of CSD include:
Tapeworm larvae and the larvae of other parasites sometimes infect fleas. Infected fleas can spread parasites to animals and humans. Animals and humans must swallow an infected flea to acquire a parasite. Animals may swallow an infected flea while grooming. Humans rarely acquire parasites from infected fleas. Most cases involve children, who spend more time on the ground around places where fleas hide. Symptoms of parasites include:
You should see a healthcare provider if you experience an allergic reaction to flea bites or develop symptoms of a disease or parasite carried by fleas.
A note from Cleveland Clinic
Flea bites are an itchy, annoying problem for you and your pets. In most cases, flea bites are ultimately harmless. But you shouldn’t scratch your flea bites. You can relieve your itch with many over-the-counter or home remedies. Contact your healthcare provider if your bite symptoms last longer than a few days or if you develop an allergic reaction or other symptoms.
Last reviewed by a Cleveland Clinic medical professional on 08/31/2021.
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