The biggest lice. Lice - description, types, photos, where they come from and how to get rid of them

Subcutaneous lice are often called scabies mites. Ticks are smaller in size, but have similar symptoms to pediculosis, they also feed on blood, but they belong to a completely different type of insect. All types of lice in humans feed on the skin, and subcutaneous mite(scabies), due to its small size, is able to make passages under the skin.

What kind of lice do people have?

Head lice

The head louse is light gray or light brown in color, this allows it to camouflage itself in the hair. Lice cannot fly or jump; the structure of their paws only allows them to crawl; the ends of their legs have tenacious claws to hold the body on the hair.

When the skin is pierced, the insect secretes a special liquid that prevents blood clotting. This enzyme causes itching and bluish spots in the affected area in humans. Optimal temperature regime for normal life, it is 33 degrees. Females lay their eggs on the hair, attaching them with an adhesive enzyme. This liquid is not washed off with water, shampoo, or insecticides.

Every day the female lays up to 6 eggs, placing them on individual hairs. Within a week, a larva is born, which after a while turns into a nymph. After two molts, the nymph becomes an adult, ready for reproduction. The transformation process from nit to adult insect takes about 16 days.

Lice infection occurs after contact with an infected person. Personal belongings and clothing are also a cause of infection. You cannot use other people’s accessories or borrow your own, for example, a comb.

Preventive measures for head lice: use only your own comb, hairpins, hoops, bows. You should avoid trying on and wearing other people's clothes, and avoid contact with people who exhibit itchy symptoms.

Body lice

This type, resistant to temperature changes. They are able to survive from 0 to 46 degrees. The most favorable temperature is 33 degrees. Lice live only in dirty clothes and can survive for up to 10 days without food.

To get rid of linen lice, heat treatment or the use of insecticides is required. It is impossible to get rid of lice in one procedure.

Body lice can carry infectious diseases. Most often, bites cause allergic reactions, pustular pathologies, pyoderma, and concomitant blood-borne diseases. Fever and types of typhus are rare in our time.

Pubic lice

Pubic lice are not at all similar to other types of their relatives. They differ not only appearance, but also a way of life.

Preventive measures include abstaining from sexual intercourse with strangers, compliance with personal hygiene rules.

Infection with all types of pediculosis is possible only from an already sick person; infection cannot occur through any other route. All types of pediculosis are treated with insecticidal preparations, heat treatment and traditional methods.

Other types of lice

People throughout their lives encounter different types lice that are not dangerous to humans.

Bird lice.

The drug Frontline has good reviews from poultry farmers, which must be applied to the naked body of birds. It is better not to process feathers; they get wet. Medicine Ivamek is applied in the same way.

The drugs Anostomozan, Piren - D are harmless to the health of birds. Water-soluble drugs, it is recommended to spray the birds with a spray bottle. Before processing, you need to carefully read the instructions; under no circumstances should you exceed the dosage.

There are many opinions about how to poison bedbugs in an apartment yourself, and I have learned just as many tips.

A person can be “attacked” by three types of lice:

In laboratory conditions, these varieties are crossed and produce fertile offspring, but in natural environment insects exist in isolation from each other.

How are they different?

A louse is a gray-brown bug measuring 0.4-6 mm, with six legs. A nit is a louse egg covered with a special membrane. The “cocoon” has a spindle-shaped shape and a “lid” through which the mature larva emerges from the capsule. At the bottom there is a belt that encircles the egg and the hair to which it is attached. The length of the nit is 0.7-0.8 mm, the diameter of the capsule is about 0.4 mm.

Outside the human head, lice live no more than two days - that’s how long they can survive without food. If the temperature environment drops to 10-12°C, pests can “last” longer – about ten days.

Life cycle of insects

The life cycle of a head louse living in human hair consists of four stages.

Fertilization and oviposition

A louse that is about two weeks old is capable of producing offspring. After fertilization by the male and the “meal”, the female lays eggs. It happens like this.

• Egg maturation. While the louse moves up the hair, the egg descends through the oviduct in the insect’s body, passing through the glands that cover it with a special composition.
• Egg release.
• Through the secretion, the egg, emerging through the anus, is attached to the hair at a distance of 2-3 cm from the root. Attaching to hair.

After a few minutes, the shell becomes so strong that it is not possible to remove the nit from the hair even with fingernails.

The louse chooses loose hair to lay eggs. There can be more than one nit on one curl only if there are a lot of insects.

Larval development

The larva develops in the cocoon in five to eight days. Ripening time depends on environmental conditions. The most favorable temperature for nits is 33 °C. When the indicator drops to 22 °C or rises to 40 °C, the development of the insect stops. At temperatures above 45 °C the larva dies; at 0 °C it can survive for two to three months. However, even in winter, the temperature of the human scalp rarely drops below 25°C, so lice can develop successfully.

all year round

Exit from the capsule

A mature larva squeezes out the lid of the “cocoon” and begins to breathe. The inhaled air passes through the insect's esophagus and, exiting through the anus, accumulates in the lower part of the shell. Under pressure, the larva is pushed out of the cocoon. The “birth” process takes only a few minutes.

Transformation into an adult

The larva emerging from the egg resembles an adult, but is smaller in size and is not capable of producing offspring. The insect grows within 14-16 days, during which three moults occur. After the latter, the pest is able to reproduce, which it does, almost immediately mating with an individual of the opposite sex.

Lice multiply on a person's head very quickly. Each female, under favorable conditions, lays about ten eggs per day.

1. How dangerous is lice for humans? Risk of infection dangerous diseases . Pests are carriers of typhus and trench fever, but in modern conditions
2. This rarely happens. Possibility of wound infection
3. . Lice leave bite marks on the skin, through which infection can enter the bloodstream. Dermatological lesions . Bite marks provoke the appearance of bluish spots, allergic reactions
4. , sometimes - pustular formations and pyoderma.. Finding lice on the head is associated with constant itching and burning.
5. Difficulty in social contacts. When communicating with other people, a person who has lice in his hair feels awkward. In addition, it is dangerous for others, since the risk of infection is high.

How can you “get hooked”

Doctors have found out where human lice come from and how they crawl from a “sick” head to a “healthy” one. Two routes of infection with pediculosis have been identified.

1. From person to person. Most often, insects are transmitted in this way. This happens when people share the same bed and sit close to each other.
2. Through personal hygiene items and clothing. When using towels, combs, hairpins and elastic bands together, pests also “travel” from head to head. You can become infected by wearing a hat, hooded jacket, or other clothing worn by a person with lice.

Nits, unlike lice, can be transmitted from person to person in exceptional cases, since they are tightly attached to the hair.

"Risk" public places

You can pick up lice anywhere through close contact with an infected person or when using his personal belongings. Most often this happens in:

• schools;
• kindergartens;
• public transport;
• cinemas.

Pediculosis can be contracted even in public bathing areas, such as a swimming pool. In poor areas of India, infection often occurs while swimming in the river.

Common Myths

Some word of mouth information about lice is incorrect. Here are five of the most common myths.

There is an opinion that lice can appear due to nervous conditions. Oddly enough, this is partly true. There is evidence that insects are more likely to “attack” those who are prone to anxiety and worry. Such people have a strong blood pulsation, excessive sweating, and their body odor is attractive to insects.

Incubation period

When lice “settle” on the head, they begin to bite immediately, however, with a small number of insects, a person does not attach much importance to the unpleasant sensations. Only after three to four weeks, when there are many pests, signs of their presence become noticeable.

How to detect uninvited “guests”...

The very first sign of head lice is itchy skin. After a pest bites, a wound is formed into which its saliva enters, causing irritation. When there are few lice, the itching is minor and is rarely associated with the presence of insects. However, the more of them there are, the more unbearable these sensations become.

The appearance of itching does not mean infection with pediculosis; the diagnosis can only be confirmed by the detection of insects and nits. Adult lice are quite difficult to see: they live on the skin and move quickly. Most often, nits are the first to be discovered. You can see light capsules with eggs with the naked eye, they are especially noticeable on dark straight hair. Sometimes nits are mistaken for dandruff.

... and distinguish it from dandruff

You can distinguish dandruff from nits by four signs.

1. Quantity. The amount of dandruff is always approximately the same, while the number of nits increases day by day.
2. Appearance. Dandruff flakes can be of different sizes, reaching 5 mm, the size of nits is approximately the same - no more than 0.8 mm. Upon careful examination, a dark egg can be seen through the nit shell; the empty capsule has a yellow or gray shade. Dandruff is always uniformly white in color.
3. Sound. If you press on the nit, you can hear a characteristic click.
4. The quality of the "coupling". Dandruff can be easily brushed off your hair, but nits are firmly attached to your hair.

How to do a head examination

Detecting lice can be difficult, especially if your hair is light and curly, or there aren't many pests yet. The only one the right way– combing with a special comb with fine teeth. It is advisable to entrust the examination to medical staff, but you can carry out the procedure at home.

How to proceed

1. Sit in a well-lit area.
2. Comb your hair with a regular comb, separating any tangled curls.
3. Comb one strand with a special fine-tooth comb.
4. Immediately after combing, wipe the tool with a white napkin or cotton pad: lice and nits will be visible against a light background if they are present on the head.
5. Comb several strands in this manner.

It is also easy to become infected with lice by using bedding on trains, in a bathhouse or sauna. In the vast majority of cases, pediculosis is caused by a head louse.

Many people are concerned about what head lice looks like. Lice move very quickly (speed 23 cm per minute), making them difficult to notice.

• The insect has a grayish or whitish color, is approximately 2-3 millimeters long, and has 6 legs.
• It is much easier to notice lice eggs - nits; head lice lay them in huge quantities.
• Nits are yellowish-white in color and are tightly attached to the hair (0.7 cm from the skin), they cannot be shaken off, like dandruff or sand.
• They have small size, no more than 1.5 millimeters.
• Typically, lice and nits are found on the scalp, but can sometimes be on the eyebrows or eyelashes.
• The life cycle of a head louse (lifespan) is 3 weeks, the insect can live outside the head for no more than a day, nits for 2 weeks.
• Lice feed only on blood, develops approximately 2-4 weeks after infection and is caused by the fact that when lice pierce the skin, they secrete saliva.

Where do lice come from - causes of lice

Where do head lice come from? Many people have misconceptions about how head lice are transmitted. Many people think that they jump or even fly. But this is not so, these insects do not have wings for this.

• Human head louse is transmitted by direct contact.
• When using common hygiene items with the patient (towel, bed linen, comb) or hats.
• The louse can run through the hair if there is contact, this is especially likely if the hair is long.
• There is an opinion that only asocial people get pediculosis, but this is not true, ordinary people There can be head lice, the causes and routes of transmission are so diverse that anyone can become infected with them.
• The places where lice are most often infected are kindergartens, schools, summer camps, baths, saunas, swimming pools, hotels, trains, hairdressers.

Pediculosis has a large epidemiological significance. The stomach of head lice contains favorable conditions for the growth and reproduction of certain microorganisms. These include pathogens of typhus and relapsing fever. These diseases are not transmitted to humans by a bite, as is commonly believed; the salivary glands and their secretions do not contain typhus pathogens. They are excreted in the excrement of the head louse or when it is crushed. If the scalp is damaged, then typhoid infection will occur. Infection is also possible when the pathogen gets on the mucous membranes or when rubbed into the skin.

Symptoms of lice

The first clinical manifestations of the disease may appear within a few weeks. The head louse finds its new host and attaches itself to the hair. She needs food to reproduce. It feeds on blood by piercing the skin with its proboscis. Small spots may remain at the bite sites, and itching may also appear in these places. Then the female begins to lay eggs. They are attached tightly to the hair, so they are not washed off during normal shampooing. After a few days, young lice emerge from them.

The main symptom of lice is itching in the affected area. The most pronounced itching is in the occipital region, in the temples and behind the ears. The disease is accompanied by decreased appetite and sleep disturbances.

When examining the scalp, damaged areas of skin with yellow crusts are visible. There may be signs of inflammation of the hair follicles - folliculitis. In places where head lice are most concentrated (behind the ears, on the temples and on the back of the head), there are changes characteristic of eczema. Upon examination, you can see nits. Empty nits are grayish in color. Complete nits are white or yellowish. When you crush them, there will be a click between the nails.

In advanced cases, the hair on the head sticks together and tangles of hair form. When scratching the scalp, the course of the disease is often complicated by furunculosis of the scalp or other pustular lesions. If left untreated, lymphadenitis develops, and the cervical and postauricular lymph nodes become enlarged and inflamed.

Diagnostic methods

Diagnosis of this disease is quite simple. It is enough for a dermatologist to carefully examine the scalp and hair. If there are nits on the hair and scratches on the head, the diagnosis of pediculosis is confirmed. Sometimes you can comb out lice White list paper.

How to get rid of head lice - how to treat pediculosis?

Previously, when head lice were detected, treatment was ineffective. Were distributed traditional methods treatment with kerosene, tar soap, dichlorvos, vinegar or cranberry juice. We strongly do not recommend using all these methods.

Present on the pharmaceutical market different means for the treatment of pediculosis. They are available in the form of sprays and shampoos (see the most full review everyone with instructions, prices and reviews). The most common means include:

The choice of drug for treatment is made by a dermatologist. Before using any of the drugs, you must carefully read the instructions and follow them strictly. All these drugs are toxic. They have a huge number of contraindications; most of these drugs cannot be used by pregnant women, small children, allergy sufferers or people with pathologies respiratory tract(cm. ).

After using these products, you need to comb your hair with a metal comb. The teeth of the comb should be very rare. Since it is difficult to get rid of head lice and nits and not all of them die when treated with products. You can remove nits by hand, but it will take a lot of time. large quantity time. Plastic combs cannot separate nits from the hair shaft. To make it easier to remove nits using a comb, you can apply olive oil to your hair. It also has anti-inflammatory and wound healing effects.

Important! After processing chemicals Do not wash your hair with shampoo for the next 2 days. You should also not use conditioners or hair balms (2 weeks), as they create a film and prevent the penetration of permethrin and other substances. If you avoid using toxic substances or the child is very small, you can comb out nits and lice on days 1, 5, 9, 13, generously applying hair conditioner and carefully combing each strand with a fine-toothed comb (see). That is, use either chemicals or conditioner to remove head lice.

Many people think that they need to shorten long hair. There is no need to do this, since the nits are located at the roots of the hair, no further than 5 centimeters from the surface of the head.

After treatment, a person should not visit crowded places (school, kindergarten, theater, cinema) for two weeks.

Since lice do not live outside the head for more than 1 day, the likelihood of re-infestation is not high, but it does exist, so you should:

• After treating the head, carry out general cleaning in the child's room.
• Wash the bedding and clothes that the infected person has worn for the last 2 days (54C is the temperature at which both nits and lice die in five minutes).
• You should also disinfect all combs and hairpins - to do this, place them in water with lice shampoo or in an alcohol solution for 1 hour. Or rinse thoroughly with a little water and put in a bag for 2 days in the freezer.
• Items that cannot be washed - hats, coats, etc. can either be dry cleaned or simply packed in bags for 14 days - during this time the nits will die.

Prevention of head lice

You must always follow the rules of personal hygiene and monitor the condition of your hair. For those with long hair, it is better to tuck their hair under their clothes or put it in a ponytail when using public transport. Never use someone else's combs, hair ties or hair clips. Do not use other people's hygiene items or towels. Don't sleep on bed linen on the train, it is better to take it with you from home. Do not wear other people's hats.

It is necessary to boil and iron the patient’s pillows, pillowcases, sheets, towels, and hats. Warn all contact persons (children in kindergarten or school, relatives), and undergo examination by a dermatologist.

Body lice are a subspecies of head lice that live in a different environment. They migrate to the human body to feed, and spend their main life and reproduction on human clothing and underwear. Insects prefer dirty things, their localization: seams, pockets, folds.

Head lice are the most common type of head lice. They live exclusively on the head of their prey. Selected localization sites are the occipital and temporal regions of the head.

People who have not encountered head lice before do not know what lice and nits look like, much less recognize the type of insect. Lice infestation is determined by certain characteristic signs.

If it is possible to destroy adult individuals almost immediately, then nits are resistant to many types of treatment and after a while young individuals can hatch and successfully continue reproduction. Mostly lice and nits need to be combed out after treatment, this will help reduce the number of larvae ready to hatch. Let's consider each type in order.

Clothes (linen, bed) louse

What do body lice look like? This species is rare in Everyday life. The insect has its own features. Main characteristic differences:

• the body is oblong with protrusions on the sides, has no wings;
• color white-yellow;
• the visual function of insects is replaced by sensitive whiskers;
• live in seams, hems, pockets of clothing;

After bites on the human body, folliculitis and pimples form. Linen lice provoke dry skin, the formation white plaque, similar to powder.
These lice live outside the human head; traces of their bites appear on open, non-hairy areas of the skin. Body lice bites are similar to mosquito bites (very itchy red bumps). The danger of bites to humans is marked by the development of allergic reactions.

What does a pubic louse look like? The presented photograph of a pubic louse shows the differences between these insects and other species of relatives. This species is smaller in size than other species; the body has a squat, round shape, reminiscent of a crab.

Characteristic features:

• thyroid, flattened tiny body, diamond-shaped;
• wide shoulder part, narrow head;
• the paws are short in length, but more massive than those of other species;
• insects are inactive, which explains the difficulty in detecting it (practically does not move);
• bodily, or beige color bodies;
• each of the 6 paws has claws;
• the abdomen is convex with growths on the sides;
• the whiskers are directed to the sides, when in other species they look forward (pubic lice move along the body, other species move along the hair due to the special localization of the whiskers);

Head lice

Using an adhesive substance, the female head lice lays eggs, firmly attaching them to the hair. The adhesive is difficult to remove chemical treatment and is not washed off with water.

Head lice bites on the head have very itchy symptoms; if not treated in time, the scratches turn into wet abscesses, which can quickly become infected. This is why lice are dangerous, without timely treatment. Sometimes, advanced lice leads to inflammation of the lymph nodes.

How long does a louse live?

How long does a louse live without a person?

Some people, embarrassed by their sudden lice infection, do not seek help from a hospital or pharmacy. They work using old proven recipes in folk medicine. The most commonly used remedies are wormwood, tansy, vinegar, turpentine, and kerosene.

Head lice infection is not associated with poor human hygiene. Most often, infection occurs in families with children. They usually become infected in children's institutions: kindergartens, schools, summer camps, sanatoriums.

Who are lice?

The suborder of lice is distributed throughout the world: they live wherever their victims are.

The development of lice goes through three stages:

• egg;
• larva;
• imago (adult).

Two species annoy humans: Pediculus humanus and Phthirus pubis ( and ). The remaining representatives of the squad are also divided according to the prey on which they can subsist. For example, there are rat and pig lice. In total there are about 500 species.

Sometimes you can find information that a person is annoyed by 3 types: head, clothes (underwear) and pubic. But from a biological point of view, this is misleading because the first two are varieties of Pediculus humanus with slight morphological differences.

Description of adults

The insect's mouthparts meet the needs of its lifestyle: it is of the piercing-sucking type. The base is a tube, at the outer end of which there are hooks that cling to the victim’s skin for stability and tight contact. It contains two sharp stilettos in the form of needles. When the insect is not feeding, it retracts the proboscis into the head capsule. Nature has also taken care of the interesting function of the anterior section of the louse's esophagus: when feeding, it contracts and expands, acting as a pump. Thanks to this, the insect sucks in blood.

Insects do not have visual organs, although in some species they are replaced by pigment spots. Lice do not need eyes: they navigate in space with the help of short antennae. They capture odors, performing an olfactory function.

Lifestyle

The louse spends almost its entire life on the body of one owner, only in in case of emergency looking for a new victim. The average lifespan of lice is 38 days. The insect is very sensitive to environmental conditions:

You should also pay attention to the question that interests many, how long lice live outside humans. Having lost its food source, the insect soon dies: this usually takes 2 days, although the most tenacious individuals can last up to 10 days.

On the human body, lice choose the warmest and most secluded places. The linen variety is usually hidden in the neck or armpits, and the head variety is usually hidden in the back of the head and behind the ears.

They live exclusively on the scalp and never move to other parts of the body. This feature is associated with the structure of its legs. They are only suitable for moving through hair with a circular cross-section. If you look at the cut of the hair growing on the body, it will be triangular.

The life cycle of a louse, despite its short duration, is quite interesting. Insects are characterized by sexual reproduction, which occurs in three stages:

Procreation of the species requires the females to actively feed on blood. Reproduction is not possible if the ambient temperature is less than 21 °C and higher than 37 °C. The development period of the embryos inside the eggs also depends on this indicator. If it is about 36 °C, then the larvae will be born in 4–8 days. When temperatures remain around 23°C, the development process can take up to 16 days. When the temperature drops to 22 °C and increases to 40 °C, the larvae do not hatch from the eggs.

The vitality of the lice population is also explained by the number of eggs the louse lays: from several dozen to several hundred in prolific species.

Nutrition

Lice are insects with an intensive feeding regime. In 24 hours they “feed” more than 10 times, and for each “meal” the individual absorbs approximately 0.5 ml of blood. The process of blood sucking, made possible thanks to the special structure of the oral apparatus, takes place in several stages:

1. From the proboscis, located at the end of the head of the louse, two sharp stilettos appear in the form of needles, which pierce upper layer skin. Such knives are modified parts of the lower lip and upper jaw.
2. From the fold that surrounds the proboscis tube, when it is everted, hook-like processes appear. With their help, the insect's mouthparts tightly adhere to the skin of the victim.
3. Through the hole made, the louse injects saliva into the skin, which is produced in abundance by the glands. It contains coagulants, when administered, the blood stops clotting and, therefore, the wound does not heal.
4. By alternating contraction and expansion of the esophageal tube, blood is drawn from the capillaries into the abdomen of the insect.

The only substance suitable for feeding lice is the blood of warm-blooded animals. Their oral apparatus cannot swallow any other organic parts of the body - for example, hair or dead skin flakes. But the closest relatives of lice are capable of this: lice eaters and lice eaters, which sometimes causes confusion.

Nits and nymphs

Nits are lice eggs, from which the next stage of insect development, the nymph, emerges. They have an oval shape. Embryos are reliably protected from unfavorable conditions environment with a dense shell having a yellowish tint.

For development to be successful, there must be suitable temperature and humidity, otherwise the embryos in the eggs die. On the human body, conditions are almost ideal, while outside it the nits die. The eggs are securely attached to the hairs and fibers of clothing using an adhesive substance secreted in special glands in the female during egg laying.

Harm to humans

Dealing with lice is not so easy: they attach very tightly to the hair in their habitat, as well as to the fabric of clothing. Therefore, simply shaking and washing your hair will not be enough.

Therefore, if a person has lice, it is necessary to immediately begin their destruction. The danger of infection also lies in the fact that insects are easily transmitted to others through personal contact and sharing household items.

• relapsing fever;
• Volyn fever;
• rat typhus;
• relapsing fever.

All these diseases are dangerous for the human body. They cause damage to the cardiovascular and nervous system, as well as other organs. Previously, infection with typhus meant high probability death, but with the start of antibiotic use, the chances of a favorable outcome increase many times over.

History of neighborhood with lice

Ways to deal with lice

Hygiene is key. You should try not to use other people's towels, combs and other personal items.

Still widely used today folk remedies. They involve the use of herbal ingredients (for example, black cumin) and substances that have an aggressive effect on insects: for example, vinegar and kerosene. But the easiest and fastest “folk” way to get rid of lice is to dye your hair with dye containing hydrogen peroxide, covering it with applied chemical composition plastic bag.