When we talk about fleas the first thing we usually think of is the image of an animal infested by these beings , often a dog or a cat, scratching continuously at the itch.

But not only can these animals suffer from flea bites, they can also easily infest humans. In this article we are going to talk precisely about the flea bite and what it means .

This is what fleas look like

Fleas are small insects, usually between one and seven millimeters in length , which are part of the order of siphonaptera or wingless insects. Their body is hard and resistant, having a relatively small head compared to the rest of the body. They have long and strong hind legs that allow them to make great jumps, this being the main mechanism by which they move and jump from one organism to another.

They are parasitic insects that feed mainly on the blood of other animals, especially mammals. They have saw-shaped jaws that generate a tear in the skin through which they can feed. In the case of females, they need this blood to lay eggs, which they often do throughout their lives.

Eggs are usually laid on the host, with the mother flea providing small fecal remains that provide digested blood to nourish future larvae. There are numerous species of fleas, and differences can be found with regard to their morphology or the type of species they infect .

The Flea Bite: Symptoms

Fleas bite to feed on other animals, mostly mammals. In this sense they are frequent in animals such as dogs, cats, rats or horses. But they can also bite humans and jump from one species to another. Their bite tends to be on the limbs (especially the lower ones), at least in humans. The sting in question can be painful .

Once produced, it is sometimes difficult to distinguish between flea bites and other insect bites. In this aspect, the fleas are characterized by easy bleeding from scratching (in fact it is common to find traces of blood on clothing or sheets when the bites are on humans) and for being arranged in rows, since these beings tend to move in different points to bite instead of focusing on a single area.

Our skin’s reaction to a flea bite is usually quick, appearing within a few minutes. Usually a small lump appears with a spot in the centre (where the flea has pierced the skin), which generates a high level of itching and redness of the area . It is common for the area to become inflamed (and not just the bite itself).

A possible complication of a flea bite is the appearance of a skin infection, which will often be accompanied by fever and other symptoms typical of infection such as fever or tiredness. Sometimes, in severe cases, anemia may occur.

Another possible complication is in people who are allergic to their sting, which could lead to blisters and rashes, emotional sensitivity, tiredness, diarrhea, or breathing problems that could lead to anaphylactic shock.

Some diseases transmitted by fleas

A flea bite is usually annoying but does not usually cause major complications. However, as with mosquitoes, there is a danger that they carry viruses or bacteria that can transmit disease.

Not for nothing, it was the bite of the fleas that caused the spread of one of the greatest pandemics in history: the Black Death . This disease was introduced into Europe by fleas from rats travelling on boats, through the transmission of the bacterium Yersinia pestis, and caused the death of between thirty and sixty percent of the population throughout the territory through which it spread (at that time most of the known world).

Although bubonic plague (which generated buboes and caused significant lymph node inflammation) is the one that generated the greatest pandemic and the most common and best known, the truth is that there are also pneumonic plague, neurological plague and septicemic plague. Although it is not currently considered the pandemic that it once was, there are still some cases of this disease.

Apart from the plague, it has been seen that flea bites can transmit diseases such as typhus or leishmaniasis, among many others. You can also introduce tapeworm or tapeworm eggs if the flea is ingested accidentally or voluntarily (for example by some children). These diseases can be spread within a species or passed on to other species, and it is not impossible for them to be transmitted from animal to human or vice versa.


Usually the flea bite per se is not treated or treatment is sought unless accompanied by allergic or other symptoms . Usually no treatment is received, with the possible exception of applying cream. In cases of allergy, the use of antihistamines will reduce the symptoms. In cases of anaphylactic shock and/or the use of glucocorticoids, it may be necessary to inject epinephrine. If any type of bacteria has been transmitted, antibiotic medication will tend to be used.

What is important is prevention: hygiene of the environment and of the person and/or pets will make the possibility of infestation more difficult. It is also essential to keep both human and animal vaccinations up to date so that certain diseases cannot be transmitted to them. It is recommended to use pipettes on pets to avoid the approach of fleas. Special care must be taken with pregnant women and children, as they are at greater risk.