What is Pediculosis (Lice)?
Pediculosis (lice) (from the Latin. Pediculus “louse”) – a parasitic disease of the skin and its derivative – hair.
The head louse (Pediculus Humanus Capitis), the body louse (Pediculus Humanus Corporis) and the pubic louse (Phtyrus Pubis) can parasitize a person. Accordingly, head, clothes and pubic pediculosis are distinguished. Mixed pediculosis may also occur when mixed type infestation is present (eg, simultaneous infestation of head and wound lice).
Lice feed on the host’s blood, and the eggs (nits) are glued to the hair (a clothes louse lays eggs in the folds of clothes, less often sticks to the hair on a person’s body).
Lice are associated with humans since ancient times. The first reports of them are found in Aristotle (4th century BC). Dried lice were found in ancient human graves: in Egyptian, Peruvian and Indian mummies. Lice are also found on the mummified corpses of people in Greenland and the Aleutian Islands (XV century).
Almost 500 years BC. er Herodot wrote that the Egyptian priests and clerks always had their heads thoroughly shaved, “… so that no louse or other unclean creature could cling to them when they serve the gods …” For the same purpose, pharaohs, kings and nobles in Ancient Egypt, Babylonia and Assyria.
In Europe, outbreaks of pediculosis have been regularly observed for 200 years. The peak of the incidence is at the beginning of autumn, when children return home from camps and boarding houses.
An increase in the number of patients with pediculosis is observed when people live crowded together and / or in unsanitary conditions, for example, during wars, disasters. Many are convinced that it is easier to get head lice infected with nervous, constantly worried people. Sometimes it is associated with a change in the smell of a person under constant stress.
Causes of Pediculosis (Lice)
Head lice (Pediculus humanus capitis) are transparent or greyish-yellow insects up to 4 mm in length, parasitizing mainly in the temples and the nape, from where they can spread to other parts of the head. For 20-30 days the louse lays up to 10 eggs (nits) per day. After 8-10 days from the nits are formed the larvae, then turning into an adult louse, which after 10-15 days begins to lay eggs itself. Longevity lasts up to 38 days.
Lice do not jump and do not fly, they crawl. Consequently, the infection occurs through direct contact of hair, especially long, as well as through a towel, comb, and other things. A louse can crawl from one head to another in an electric train carriage, in a store, on a beach, in a pool.
When a bite lice secrete saliva, causing quite severe itching. This leads to the appearance of scratching, violation of the integrity of the skin, the development of bloody crusts.
Head lice are transmitted from person to person through direct contact (or through clothing, underwear, household items, hairbrushes, etc.).
A body louse (body louse) (Latin: Pediculus humanus corporis De G. var. Vestimenti, sometimes just Pediculus corporis) is an insect, a human parasite with strict monoxeness.
Body lice were known in ancient times.
It is believed that in 1909 Charles Nicole, in experiments on the infection of body lice in monkeys with typhus, first established that lice are a carrier of typhus. However, in the domestic literature there are descriptions of the fact that this fact was established almost two decades ago (in 1892) before the experiments of Nicolas, Professor of Kiev University G. N. Minh.
A clothes louse usually parasitizes a person’s clothing. At the same time she lives and lays eggs (nits) in the folds of clothes and on her nap, and feeds temporarily moving from clothes to the skin.
Lice are well adapted to food on the hosts. In this case, it is believed that the clothes louse, unlike the head, evolutionarily younger species of the parasite, since clothing as a substrate for the residence of arthropod appeared much later than hair on the skin of mammals.
The parasite insect’s mouth apparatus is a piercing needle, enclosed in a soft tube (proboscis) that everts out of the mouth and whose edges are pressed tightly against the skin to be pierced. Bleeding is carried out by muscular contractions of the pharyngeal pump and pharynx. Saliva lice contains an enzyme that prevents blood from clotting.
From the short esophagus, blood enters the highly dilated stomach. Usually an adult individual drinks from 1 to 3 μl (0.001-0.003 ml) of blood. The average weight of an insect is 1 mg. Females are bigger in size and weight and drink more blood than males. Through translucent chitin, the process of feeding lice with blood is clearly visible: their abdomen swells, the intestine rhythmically contracts, taking in more and more new blood, and its body becomes dark red.
In 2010, the gene was wrapped lingerie. Its volume turned out to be the smallest among all known insects – only 108 million pairs of nucleotides.
Pubic louse or ploshchitsa (Latin Pthirus pubis) – ectoparasitic insect from the sub-order of lice (Latin Anoplura), living on the human body mainly in the pubic zone, on the genitals, around the anus, less often in other hair-covered areas: in the armpits, on the chest and abdomen, eyebrows, eyelashes, mustache, beard. It feeds exclusively on the blood of its owner. Without food dies within 24 hours. However, outside the human body can fall into anabiosis and stay in it for up to several months. The disease caused by the defeat of this insect is called pubic lice or phthyriasis.
The size of the pubic louse reaches approximately 1-3 mm. Females are 1.5 times larger than males.
The pubic louse lays its eggs at the base of the hair, and itself is attached by a proboscis to the mouths of the hair follicles, usually on the skin of the pubis and scrotum. Infection occurs mainly through sexual contact. Infection through bed linen is possible.
It is impossible to catch lice from animals, since these parasites are species-specific and can only live on an animal.
Symptoms of Pediculosis (Lice)
The incubation period from the moment of infection until the onset of symptoms can last up to 30 days or more.
Getting on the hairy part of the skin, and attaching to the hair with the help of mites located on the legs, the louse sticks its oral apparatus into the skin and sucks blood. At the site of the bite, under the influence of irritation of the skin by the secret of the salivary glands, itchy spots and nodules appear. On the skin of the abdomen may appear bluish spots, they are formed from hemoglobin of the blood under the influence of an enzyme produced by the glands of lice. Also signs of pubic lice can be small red spots on underwear – these are secretions left by parasites. If an infected patient has abundant hairiness, then the pubic louse can crawl onto the skin of the chest, abdomen, thighs, limbs, underarms, eyebrows and eyelashes. With an increase in itching, scratching occurs, leading to an increase and spread of inflammation, ulcers and crusts form, peeling of the skin. Against the background of scratching an infection can join, then small abscesses appear on the skin.
Pediculosis of the body is rarely observed when following the rules of personal hygiene. But if it does occur, then skin lesions are more often seen on the shoulders, buttocks, and abdomen. With such symptoms, you should immediately check the clothes (most often the folds of underwear), in the seams of which adult lice can live and lay eggs. The most common symptom is itching, leading to scratching the skin and attaching a secondary infection. Uninfected bites look like red spots between 2-4 mm in diameter.
As a result of the infection of the combs, pustular skin diseases can develop.
It is worth noting that body lice are the main carriers of typhus and a number of other rickettsioses. Much less often typhus is transmitted by head lice, in isolated cases – ploschitsy.
Diagnosis of Pediculosis (Lice)
All persons who seek medical help and undergo routine medical examinations are subject to examination for pediculosis.
When examining a patient, lice can be seen with the naked eye. Insects are better distinguishable after drinking blood. With pubic lice, lice look like gray-brown spots located at the root of the hair. Lice are completely immobile, but when trying to tear them off, they show signs of life and even more actively cling to the hair, which they tear off with great difficulty. More often find nits attached to the hair.
Pediculosis (Lice) Treatment
For the treatment of pediculosis, an integrated approach is needed that will destroy both nits (eggs) and adults. Wrestling methods are different for different types of lice.
To get rid of the ploshchitsy (pubic lice), you can use the following method:
- Shave all hair where possible (pubic, armpit), in order to avoid infection of the bite site, disinfect with 10% white mercury ointment.
- Remove eyelids from the eyelashes and eyebrows.
Linen and clothing should be boiled or steamed. a simple low-temperature wash may not be enough. After high-temperature treatment, hang out the laundry for a week, preferably in the sun in a ventilated place.
Another method involves treatment with an insecticidal preparation, followed by washing and weekly airing in the sun.
The most effective is the decontamination of clothing and linen in the steam-formalin chamber. This method is more effective because combines high temperature and chemical treatment.
When processing clothes, it should be taken into account that nits can be deposited in thick folds and seams of clothes, where they can withstand insufficient heat treatment.
Considering the special epidemiological significance of ward lice and the possibility of fixing nits not only on the nap of clothing, but also on the vellus hair of a person’s skin, with a common process it is necessary to decide not only about the disinsection of clothing, but also about the treatment of a patient with one of the pediculocid preparations.
- The best way: to comb out adult lice, then 3-4 days, as itching appears – hot hair dryer. until you dry all new ones.
- Pharmacies now sell a wide range of anti-pedicular drugs – shampoos, ointments, aerosols. The most famous pediculocides (drugs that kill lice and their nits):
• Chemerichnaya water
• Pair plus
• Serortut ointment
• 20% water-soap suspension of benzyl benzoate (a preparation for the treatment of scabies, previously used also against pediculosis, but now it is not recommended)
• 5% boric ointment
• Butadion (ointment for healing wounds from bites)
Of these drugs, some do not have ovocidal (killing nits) effect. Even with the oocytic effect, some nits tend to survive, so it’s important to remove them mechanically. Studies in Western Europe, Canada and the United States, Israel, Argentina, Russia found that head lice become resistant to most anti-pediculosis drugs, which complicates treatment with such means as permethrin and phenotrin. Therefore, now all over the world there are natural remedies for lice and nits. In Russia, this tool is ROSH TOV Double Impact. Contains plant and oil extracts that are not pesticides and are approved for use in cosmetics. Natural products do not act like chemicals. The respiratory system of lice consists of respiratory tubes or trachea – branching out all over the body and communicating with spiracles located on the sides of the abdomen and chest. Molecules of essential oils penetrate the respiratory system and clog the respiratory openings of lice. Lice are killed by suffocation and dehydration. Due to the physical mechanism of action, as well as the fact that polysaccharides in the composition of oils and extracts are also included in the structure of insects, it is difficult to develop resistance of lice to the ingredients of such preparations.
When using any means of lice should be as precise as possible to follow the instructions, because these drugs are very toxic. Many of them are contraindicated in pregnant and lactating women, small children.
There are also numerous popular recipes for getting rid of lice. They are usually less effective compared to pharmacies and not necessarily less toxic. Do not use them just because you are ashamed to buy money from head lice at the pharmacy.
- 50% sunflower oil + 50% kerosene
- 50% of household soap + 50% kerosene, dilute the resulting concentrated solution before applying to hair with 1:10 water (100 ml of solution per 1 l of water)
- Cranberry juice (effective against nits, as it dissolves the upper shell of the egg with its acidic environment)
- Vinegar (9% table vinegar is diluted twice with water to obtain an acid concentration of 4.5%)
- Dustov soap
- Tar soap (valid due to high alkali concentration)
- Essential oils (tea tree, lavender) – put on the hair a few drops not for treatment, but for the prevention of infection with lice, for example, to uninfected family members.
Keep in mind the shortcomings of folk remedies:
- Kerosene is flammable, poorly washed off, spoils the hair (it becomes sticky and dirty to look), makes it difficult to comb;
- Vinegar dries hair, and a concentrated solution can cause severe burns;
- Dichlorvos and similar products are VERY TOXIC. You can get poisoned.
In addition, the use of such funds is associated with inconveniences: you need to wear a plastic bag on your hair, wrap a towel around your head and keep it in such a form for a long time.
There is another rather radical way to destroy head lice – this is hair dyeing with synthetic paint. Paints contain many caustic chemicals that kill lice and nits.
After using any means, it is necessary to comb the head with a special frequent comb and remove each egg manually. It will take several days, as it is not easy to get the nits out. To achieve maximum efficiency, you should comb the hair with a comb with a very small tooth pitch – for example, with a special AntiV frequent comb. Normal comb badly remove nits, when using them, you must additionally remove the nits with your fingers. If the hair is long, then it will have to be cut at least to the shoulders, to make it easier to comb out dead insects and eggs. To facilitate combing can be applied to the hair with a balm, fish oil, oil, giving a “slip effect.” Olive oil eliminates parasites, and geranium oil also has an anti-inflammatory effect and heals wounds.
When dealing with head lice, it is extremely important to neutralize (boil, iron) the personal clothes of the person who has been tested (pillows, towels, pillowcases, sheets, etc.). Other family members (classmates, children in the same kindergarten group, etc.) should also be examined for infection.
Prevention of Pediculosis (Lice)
- Observance of personal and public hygiene: regular body washing (at least 2 times a week), change of underwear and bed linen; washing bed linen at high temperature, ironing clothes with a hot iron, especially the seams, where lice usually lay eggs.
- Preventing the transfer of personal combs to others.
- Apply fluids from tea tree and lavender to the back of the head and behind the ears to prevent the appearance of lice.
- Boiling used items (mainly towels, hats, bed linen, clothes with hoods and collars, soft toys) in order to prevent re-infection with lice.
- To check for lice, brush your head over a light cloth.