23rd August, 20217 min read

Flea bites on humans: What they look like and how to treat them

Medical reviewer:
Healthily's medical team
Healthily's medical team
Alex Bussey
Alex Bussey
Last reviewed: 04/08/2020
Medically reviewed

All of Healthily's articles undergo medical safety checks to verify that the information is medically safe. View more details in our safety page, or read our editorial policy.

What do flea bites look like on humans?

Fleas are parasitic insects that feed by sucking the blood of humans and animals. They often live on animals like cats, dogs or rats, but they’ll still feed on humans if they can.

Fleas are small and hard to see, but their bites are difficult to miss. Flea bites normally look like small, red lumps on your skin and are normally found in small clusters on your lower legs – often around your ankles and feet. It’s also common to find flea bites on your waist, and they can also appear on your arms if you’ve been petting or carrying an animal that has fleas.

These lumps can be extremely itchy or painful, and you may be able to see a small hole or puncture mark (called a punctum) in the middle of the bite.

It can be quite hard to tell the difference between a flea bite and other types of insect bites, such as a bedbug or a mosquito. If you’re worried and want to know what’s bitten you, ask a doctor to take a look at your bite. They’ll be able to help you work out whether you’ve been bitten by a flea and to check for any signs of infection.

How long do flea bites last?

Flea bites are normally harmless and most will fade in a matter of days. They normally clear up on their own after a few hours or a few days, depending on how you react to the bites and how much (or little) you scratch them.

If you scratch them, they can get infected and will then take longer to heal – you’ll need to see a doctor for any infections, as you may need medicine like antibiotics to treat the infection.

And if you have an allergic reaction to flea bites, the symptoms may take many days or even weeks to go away.

What an allergic reaction to flea bites looks like

Some people are hypersensitive (extremely sensitive) to some of the chemicals found in flea saliva. This makes the bites swell up after a few minutes and form an itchy blister or hives (urticaria) that lasts for several days or weeks.

These blisters may ooze or form a crust when they are scratched, known as papular urticaria.

Papular urticaria is normally harmless and self-limiting, which means that it will go away on its own. But the condition can be very irritating, so if you’re struggling with a swollen bite, it may be worth talking to a doctor or a pharmacist about taking an antihistamine to reduce some of your symptoms.

Flea bite on human skin

What infected flea bites look like

If you scratch your flea bites, they can become infected as scratching can irritate your skin and push harmful bacteria into any open sores. Infected bites may become painful, red and pus-filled, with signs of oozing or crusting around the original site of the bite.

Infected bites should always be examined by a doctor, and you may need to take a course of antibiotics to help your body deal with the infection.
Fleas in some parts of the world also carry diseases like typhus or bubonic plague. These conditions are rare in countries like the USA or UK, but they’re more common in parts of Asia, Africa and the Americas, and can be very dangerous if they’re not treated properly.

Some fleas can also carry dangerous infections like bubonic plague or typhus. These diseases are more common in some parts of Africa, North and South America and Asia.

Typhus is a serious bacterial infection with symptoms of:

Plague is also a serious bacterial infection. It has many different forms, but bubonic plague is the most common. This causes symptoms of fever, chills, nausea and vomiting. It also infects your lymph nodes, causing characteristic swellings called buboes.

How to treat flea bites

You can treat a flea bite by washing the surrounding area with an antibacterial soap to prevent infection.

Talk to a doctor or pharmacist about using a calamine lotion or an anaesthetic cream if your bite is itchy, and try to resist the urge to scratch so you don’t increase your chances of getting an infection.

If your bite swells up, try applying an ice pack to the affected area, or talk to a pharmacist or doctor about using an antihistamine to relieve your symptoms.

You should see a doctor if your symptoms get worse, or you see any pus leaking from your bites. This could be a sign that your bite has become infected and you may need antibiotics to get rid of it.

Read more about the best treatment for insect bites.

How can flea bites be prevented?

Fleas can live for several weeks or months in carpets, soft furnishings, animal bedding or soil. They do this by creating protective cocoons, and lying dormant (inactive) until they sense that a potential host is nearby.

The best way to prevent flea bites is to stop fleas from infesting your home. To do this you can take the following steps:

  1. Wash pet bedding once a week, and vacuum your carpets and soft furnishings — this is to remove any flea eggs. Take care to get rid of any vacuum bags properly.
  2. Tumble dry your pet bedding — this is also effective in killing fleas and their eggs because of the high temperatures reached.
  3. Treat any outdoor areas with insecticides that target fleas.
  4. Try to stop animals that are carrying fleas from entering your garden by putting up high fences or walls.
  5. Clean your pets with warm water and the correct shampoo to help kill fleas — you can speak to your vet about flea treatments if you suspect that an animal in your home is carrying fleas.

All cats and dogs should be treated regularly for fleas by a vet. This is the best way of preventing an outbreak in your home.

woman stroking cat

When to see a doctor about flea bites

If a flea bite becomes worse over time, infected, you have symptoms of bubonic plague or typhus, or if you feel unwell or have an allergic reaction you should see a doctor. Signs of infection include:

  • swelling, redness and increasing pain around the bite
  • pus forming in and around the bite
  • a high temperature (fever) of 38C degrees or above
  • feeling generally unwell
  • swollen glands – under your chin, in your neck, armpits or groin

Key takeaways

  • flea bites normally leave small, red lumps on your skin. These lumps can be itchy and irritating
  • they’re often found on your ankles or legs, and often appear in clusters or lines
  • most flea bites are harmless, but they can get infected if you scratch them
  • you can treat them by washing the affected area and applying some anaesthetic cream. Painful, red or swollen flea bites should always be examined by a doctor
  • the best way to avoid flea bites is to keep your house clean and treat your pets for fleas
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