The human louse is a parasite, the peculiarities of its biology and parasitic lifestyle are not similar to any other insect harmful to humans. Lice on closer examination are very original arranged bloodsuckers, in many ways more than other "competitors" who have adapted to life on the human body.
More about these interesting features of human lice and the specifics of the fight against them, we'll go on and talk.
It is interesting
Evolutionary lice can be considered a kind of transitional stage in the parasitism between typical "blood hunters", such as bed bugs and fleas, whose entire life passes away from the person, but who attack it only for nutrition, and internal parasites such as scabies mites life spends under the skin of a person. The human louse has already become completely dependent on the human body, but has not yet managed to penetrate its veils. This determines the specifics of problems with lice, and the relative simplicity of the fight against them.
What is dangerous for human lice?
The main dangers from the presence of human lice on the body are the body's reaction to the bites of parasites and the transference of lice of some dangerous diseases by lice.
Usually lice in humans cause a complex of responses of the body, called in medicine by pediculosis. Such reactions are expressed in the appearance of:
- severe itching at the bite site
- rashes on the body, not only in the places where the bites were localized, but also on the surrounding skin areas
- appearance of bluish spots due to redistribution of pigments
- sometimes - a generalized allergic reaction with an increase in body temperature, headaches and nausea.
In neglected form, pediculosis can cause ulcers, boils and the appearance of deep scars on the skin.
In addition, lice in humans are carriers of microorganisms from the rickettsia class, some of which are agents of typhus and recurrent typhus. At one time, it was these deadly diseases spread by lice that mowed soldiers in the Russian army, and today their epidemics continue to erupt in some countries of Africa and South America.
On a note
Head and pubic lice very rarely suffer typhus. Nevertheless, because of the potential danger, they are actively fighting in children's groups and health care institutions.
But how to distinguish between different types of human lice - a separate big question ...
Types of lice in humans
Generally speaking, a person has only two kinds of lice - the so-called pubic and human. In this case, the human for all time of neighborhood with a man managed to split into two forms - head and tail.
In the photo below - head lice on a heavily infected head:
And then - photos of pubic lice:
Even lower - a photograph of clothes (linen) lice on clothes:
It is interesting
Lice are parasites very attached to one master. Human lice can not live on other animals, and therefore, lice can only be infected by humans. Conversely, withers in animals are never parasitic in humans.
The pubic louse is known for being found mainly on the pubic hair, occasionally in the armpits. Look pubic lice in humans rather specific - they have a very short body and long, powerful legs. Here is another photo of pubic lice:
The size of pubic lice is up to 2 mm.
Human lice have a slightly longer torso than pubic lice. Head lice are slightly darker, and the wardrobes are almost completely white. When saturating the abdomen, the lice darkens at the expense of blood in the stomach, and each insect becomes a bit like a flea or a blood-drenched larva of a bed bug (see photo):
In length, human lice reach 3-4 mm, but due to the fact that they live among the hair or folds of clothing, they rarely come to their eyes. The photo below shows an adult insect:
Regardless of the type and shape of the lice eat only blood. They can not penetrate the human skin and can not live long outside the body. Pubic and head lice spend most of their time on the hair, and the clothes are mostly on clothes that people do not practically take off.
What do human lice look like?
A human louse is a very small insect. The photo below shows lice and their eggs (nits):
The maximum length of adult lice is about 4 mm. Lice look like human small wingless bugs. In this case, head and ward lice have a body of light-white color with translucent covers, and pubic louse - brown.
In human hair, lice are not noticeable: they are mostly found at the base of the hair and on the scalp. More visible here are the nits - they look like very small white dots, located at different distances from the base of the hair. Nits are lice eggs that are firmly attached to the hairs by a female.
The following photo shows the abundance of nits on the infected head:
And on the following photo you can see how lice look like in a person during feeding:
On a note
A human louse is especially noteworthy for the way it looks every foot. When viewed under a microscope, you can see that the last leg segment is a hook, well adapted to grasping by the hair. According to the structure of the legs alone, it is easy to distinguish lice and withers from other parasites, but without powerful optics it is indispensable here.
From the most common parasites of humans, lice are quite good:
- Bed bugs are larger and brown in color. Their larvae may resemble lice, but they move much more quickly and do not occur on those parts of the body where lice are usually parasitized in humans.
- Lice and fleas in humans usually do not occur on the same areas of the skin - fleas prefer to bite their legs, sometimes - behind the sides of the body. Near the hairy parts of the body, fleas practically do not bite.
- The mites bite the person mainly by the legs and differ from lice with the dark color of the body, 8 paws (lice have 6 of them) and very long sucking of blood.
- Scabby mite is much smaller than lice and lives exclusively under the skin. It causes itching, but its activity does not cause bites, characteristic of lice.
Photo of a bed bug:
Photo of the flea:
Photo of the tick:
And so it looks like an itch mite:
From other blood-sucking parasites of human lice can also be distinguished by the appearance of the bites themselves. In bugs and fleas, bites are often located on the same line - the insect bites several times, moving a few centimeters from the previous place of sucking blood. Lice do not do that. And ixodid mites leave behind a fairly large solid cone - bites of lice are much smaller in size.
Below are a few more photos of human lice, allowing you to learn more about the appearance of these parasites:
"When the child started scratching his head in September, I thought that again he was bitten by bugs, six months ago, it was like that, they only bit their backs and sides. Again, the apartment was plagued by Carbophos, everything was well done, and the scabies did not pass. They began to look closely and found nits. At first I did not believe, I thought lice had long since disappeared, I decided to see what a human louse looks like, and exactly - on the head of Andryusha they were exactly like that. I had to buy shampoo, put on the head packets and poison. Most likely, in the summer camp he picked them up. "
Reproduction of lice, their nits and larvae
All life and reproduction of lice takes place on the human body (or on his clothes - in the case of lice). In this case, there is no difference, there are lice in an adult or a child - the features of their biology do not change from this.
An adult human louse lives up to 40 days and females lay eggs literally from the first day of their adult life. The egg, it's nit, is attached with a special sticky slime to the hairline, and after 5-6 days a larva, similar to a copy of an adult louse in miniature, is removed from the nit.
Up to 20-25 days the larva of the louse feeds, several times molts and turns into an adult insect.
The photo below shows what the larva of a human louse looks like:
In louse lice, eggs are deposited in the folds of clothing. There is also the development of larvae.
Larvae of lice feed on blood, as do adult insects.
It is interesting
At temperatures below 22 ° C and above 40 ° C, human lice do not multiply - larvae are not hatched from their eggs.
The larvae of all kinds of human lice under a microscope seem transparent and look as if they have been deprived of wings.
In pubic and head lice, adult individuals become slightly darker, while the wearers remain as light as the nymphs.
How are human lice spread and transmitted?
Lice in most cases are transmitted by close contact with an infected person. Especially heavily prone to infection with lice, children who are easily in contact with each other and are not particularly restricted in games and brawls.
Also head lice can be transmitted through combs, elastic bands and hairpins. Louse lice can crawl from one thing to another when storing clothes together.
Pubic lice are transmitted almost exclusively during sexual acts. Only sometimes they can infect a person by falling on bed linens and moving to the one who will lie on the bed next. Such cases take place, for example, in cheap hotels.
On a note
Exceptionally rare, but cases of carrying lice on water in swimming pools and places of public bathing are recorded. Lice are resistant to lack of oxygen and can survive for 2 days in water.
Now, knowing how lice look, it will be easy for you to determine the fact of infection of yourself or your children and take appropriate measures in time. It is also useful to remember about simple preventive measures that will limit our acquaintance with human lice with only theoretical information.
Getting rid of lice and nits at home for 1 procedure: