Scabies

Scabies. Description, symptoms, prevention and treatment of scabies

Scabies (lat. Scabiei) - a contagious skin disease caused by a microscopic parasite - scabies or itch mites (lat. Sarcoptes scabiei var. Hominis).
The name comes from the other pathogen. -grech. σάρξ (meat and flesh), κόπτειν (to chew, tear, cut) and the Latin. scabere (comb).
Characteristic features of the disease are itching and rash papulovezikuleznaya, often with the addition of secondary pustular elements as a result of infection by scratching. The word "scabies" is the same root with the verb.

History of the study of the diseaseThe first descriptions of scabies made more than 2500 years ago. Scabies is described in the Old Testament and in the writings of Aristotle. In ancient Greece, mange refers to a group of skin diseases combined term "psora". In ancient Rome, scabies called "scabies" is the name survived to this day. In medieval treatises speculated about the parasitic nature of scabies.Credible evidence of the role of scabies mites in the development of the disease appear only after the creation of an optical microscope. In 1687, the Italian physician Giovanni Cosimo Bonomo and pharmacist Dyachinto Cheston first described the link between scabies and typical skin symptoms that develop after infection. It was the first time they have found that the disease can be caused by microscopic organisms.Full and accurate description of the etiology and pathogenesis gave in 1844 a German dermatologist Ferdinand Hebra. This manual was in 1876 translated into Russian Polotebnevym AG.

How is scabies?Infection with scabies is almost always occurs during prolonged direct contact with the skin, the skin. Mostly sexual transmission. Children often become infected when they sleep in the same bed with sick parents. In the crowded bands are realized and other direct skin contact (contact sport, raising children, frequent and firm handshakes, and so on. N.). Although a number of guidelines, continues to play outdated information about the transmission of scabies through household items (kitchen utensils, bedding and so on. N.), Experts agree on the view that such a way of infection is highly unlikely. The exception is the Norwegian scabies, when the body of the patient lives to several millions of mites (in typical cases is 10-20 ticks).A key experiment proved that the transmission of scabies dominant role played by direct contact with the skin of the patient, was performed in 1940 in the UK led Mellanby. Of 272 attempts to infect volunteers, putting them to bed, which had just climbed patients with severe scabies, only 4 attempts led to the disease.Such features parasitosis due to the following transmission data on its biology:

• - Itch mite activity during the day. Females are chosen on the surface only in pozdnevechernee and at night;
• - Mite requires about 30 minutes to infiltrate the skin of the host;
• - In the external environment mite dies quickly (at 21 ° C and humidity of 40-80% of the parasite dies after 24-36 hours) than a warmer and drier, the faster; Activity mite loses earlier.

Currently, more guidelines and health surveys include scabies pediculosis pubis along with the list of diseases, sexually transmitted diseases, although the transmission of parasitic diseases is important not so much the coitus as long contact bodies in bed.

Infection through animal scabies

Dogs, cats, hoofed animals, livestock, etc. It can be infected by different variants of mite Sarcoptes scabiei, which can be transmitted to humans. This is a picture similar to a localized skin itch caused by human variant mite (Sarcoptes scabiei var. Hominis). However, all other options are not able to tick to complete a full life cycle of the human skin, so this scabies short duration and does not require treatment skabitsidami.

The life cycle of itch miteThe causative agent of scabies is the itch mite - obligate parasite of humans. For parasite typical sexual dimorphism: females are larger than males doubled, reaching 0.3-0.5 mm. Mouthparts Sarcoptes mite - pathogen chesotkineskolko protrude on the sides there are two pairs of front legs with suction cups, two rear pairs of legs are located on the ventral surface, the females are equipped with long bristles, the male 4 pair of legs instead of bristles sucker. Eggs are oval mite larva emerged from the egg has ovoidal and 3 pairs of legs (4 vapor is absent), its size does not exceed 0.15 to 0.1 mm.Mating occurs mites on the skin surface. Immediately after mating, the males die. The fertilized female forms in the stratum corneum itch course, which lays 2-4 eggs per night. Keratin skin mites dissolved with special proteolytic enzymes contained in their saliva (formed lysate they feed). Males form short side branches in the course of the female itch. Life expectancy of females does not exceed 4-6 weeks. The larvae hatch in 2-4 days and immediately begin to form passages in the uppermost layer of the skin. After another 3-4 days the larvae molt and become protonymphs, which in turn shed 2-5 days teleonimfu. Teleonimfa develops into an adult male or female in 5-6 days. Total formation of adult tick occurs in 10-14 days.Contagious mite can be at any stage of development, but more often from person to person with scabies is transmitted Fertilized adult females.Ticks are not active in the daytime. The female begins to "dig" the course (2-3 mm per day) in the evening; at the same time enhanced itching in patients with typical forms of scabies. At night, the females come to the skin surface for mating and move to other parts of the body (on the surface of warm skin mites are moving at a speed of 2.5 cm per minute. Then there is the most favorable situation for infection. 

 
Symptoms of scabiesA typical, but not mandatory, clinical symptoms of scabies are itching, worse in the evening. The skin is formed by erythematous rash papulovezikuleznaya, combing join pustular elements and form a crust to form a polymorphic rash. Pathognomonic sign is the presence of burrows.Once the female mite falls on human skin, it immediately begins to "dig" the progress in the stratum corneum with a speed of 0.5-5 mm per day. As a result, on the surface of the skin on closer examination to be found slightly elevated above the surface of the skin line of whitish-gray in color, ranging in size from 1 mm to 1 cm. The front end of a blind turn distinguishable by the presence in it tick, which is visible through the epidermis as a dark point. Itch moves become visible after a few days in the formation peritonnelnoy host response. Most itch moves can be detected in the interdigital spaces, on the inner side of the wrist and on the skin of the penis. Sometimes the itch moves can not be found (no itch moves).Primary rash consists of small erythematous papules that may be scattered or multiple, drain. Over time, the papules can be transformed into a vesicular (vesicles), bullous rarely (pemfigoidnaya) rash. Intensity of the rash does not correlate with the number of parasites and is caused by an allergic reaction to the products of their activity.The rash is most often distributed (in descending order) in the interdigital spaces of hands on the flexion of the wrist, the men quickly passes from the hands to the penis and scrotum. Then affects the elbows, feet, armpits, under the breast area in women, the umbilical region, the belt line, buttocks. As a result, may be invoked entire body except the face and scalp (though children under 3 years are affected and these areas).The presence of itching, rash and itch primary moves is the main clinical symptom typical form of scabies.Papules and vesicles often develop secondary itch elements: excoriation (scratches), eczematous elements, secondary pustular rash and crusts. Primary and secondary cells thus coexist in the same patient.In domestic dermatology decided to allocate characteristic symptoms eponymous facilitate diagnosis:- Ardi symptom - blisters and festering scabs on his elbows and their circle;- A symptom Gorchakov - the same bloody crusts;- A symptom of the Michaelis -krovyanistye crust and impetiginoznye mezhyagodichnoy rashes in the crease with the transition to the sacrum;- Sezary symptom - detect itch moves as a light elevation when palpation.Scratching often leads to severe bacterial infection of primary cells with the development of pyoderma, which in rare cases can lead to post-streptococcal glomerulonephritis and possibly to rheumatic heart disease. Sometimes scabies pyoderma when accompanied by the appearance of boils, abscesses and ecthyma, accompanied by lymphadenitis and lymphangitis. A number of patients developing microbial eczema or atopic dermatitis, which along with pyoderma in national dermatology attributed to complicated forms of scabies.Complications in the form of scabies and dermatitis, pyoderma occur in approximately 50% of patients.When scabies described and other complications: impetigo, pyogenic pneumonia, septicemia, felon, erysipelas, orchiepididymitis, internal abscess, regional lymphadenitis.Children, especially infants, along with papulovezikulami itch and rash moves there vezikulourtikarnaya develop soak, and there are a felon onychia. The children in the first 6 months. life clinical picture of scabies often resembles urticaria and is characterized by a large number of combed and covered with a crust in the center of bloody blisters, localized on the face, back, buttocks. Later prevails small vesicular rash, sometimes bubbles (pemfigoidnaya form). In some cases in children scabies resembles acute eczema, accompanied by intense itching, not only in the field localization mites, but also in remote areas of the skin. In this connection often occur sleep disorders, complications often occur in the form of atopic dermatitis, pyoderma type impetigo. There may be lymphadenitis and limfangiity observed leukocytosis and lymphocytosis, eosinophilia, ESR acceleration, albuminuria. Infants may develop sepsis. In recent years, children have been an increase in cases of atypical scabies with blurred shapes.

Approximately 7% of patients with nodular forms (nodular) scabies, in which are formed bluish-purple or brownish skin tightening rounded 2-20 mm dia., Which can persist for several weeks, even in the absence of parasites. In fact, these seals are a special variant of scabies progress in the form of lenticular papules. The cause of these elements is a special predisposition of the skin to respond to the impact of the stimulus reactive hyperplasia lymphoid tissue in places most of its cluster. It prevails in the scrotum, penis, buttocks, elbows in front, underarm area, sometimes nodules formed in the perianal region. Nadulyarnuyu also called scabies scabious limfoplaziey. Since mites live in nodules there, their formation is due to severe immuno-allergic reaction of the host on their metabolic products. In cases of re-infestation scabious limfoplazii relapse to the old place without the presence of stroke. The nodules are accompanied by intense itching and in some cases for their treatment used corticosteroid injections.By the atypical form of scabies also include Norwegian scabies, scabies "cleanly" (scabies "incognito") and psevdosarkoptoz.Norwegian (cortical, krustoznaya) scabies was first described by Beck and Norwegian doctors Danielssenom (C. W. Boeck, D. C. Danielssen) in 1848 Norwegian scabies develops most often in patients with underlying disorders of immunity or sensitivity of the skin, but in about 40 % of cases people who are not related to the risk groups, which suggests a possible genetic predisposition in these patients. 58% of patients with Norwegian scabies observed eosinophilia, increased IgE levels (on average 17-fold) was found in 96% of cases. Clinically Norwegian scabies look like psoriazoformny dermatitis with acral distribution and availability of variable whitish scales. Usually also involved and subungual areas with the development of the expressed hyperkeratosis leading to thickening and nail dystrophy. In some cases, when the Norwegian scabies mostly affected area of ​​the scalp, face, neck and buttocks. About half of patients with Norwegian scabies did not feel the itch. Due to the fact that in Norwegian scabies on the patient's body may be more than one million live parasites (at typical forms mite count average 15 specimens), this form of the disease is extremely contagious.Scabies "cleanly" or scabies "incognito" is detected in individuals, often washable at home or by the nature of its operations. A large part of the population of itch mite is mechanically removed from the patient's body. Clinical disease consistent with a minimum of a typical scabies symptom severity. Complications often mask the true clinical picture of scabies. The most common are pyoderma and dermatitis, rarer microbial eczema and hives.Psevdosarkoptozom called disease that occurs in humans after infection itch mites (S. scabiei than var. Homonis) from other mammals (mostly dogs). For the disease characterized by a short incubation period, the absence of itch moves (mites do not multiply in the host uncharacteristic), urticaria papules on exposed skin. From human to human disease is not transmitted.

Varieties of scabiesScabies in different individuals may proceed differently.1. A typical scabies is most common. It is characterized by the presence of all these symptoms (itch, itch moves, and others.)2. Scabies no moves. To distinguish it from the typical mange that no itch on the skin moves, but there are bubbles of 2-3 mm in diameter. Scabies without stroke develops in people exposed to patients with scabies, but they have the infection occurred not by adults and larvae, the development of which takes time.3. Scabies "cleanly" is similar to a typical scabies, but develops in people who are often washed and removed from the body much of scabies mites. Thus, they have not mange proceeds expressed as typical.4. Norwegian scabies develops in people with weakened immune systems (eg, AIDS, tuberculosis), drug addicts, people with Down syndrome. Norwegian scabies takes very seriously, affects the entire body, including the head, and it is very contagious.5. Psevdochesotka (psevdosarkoptoz) develops in people who were infected by animals. Itch mite animals can cause typical human scabies and severe itching occurs only. Healing occurs spontaneously after cessation of contact with sick animals.6. Complicated scabies develops in untreated scabies and is a typical consequence of the accession of infection. Places lesions become red, painful, wet and unpleasant smell.Prevention of scabiesThe amount of preventive measures is determined depending on the epidemiological situation. Upon detection of scabies filled form of emergency notification and notified authorities SES residence of the patient.Individuals from one chamber are treated together in order to prevent re-infection. All persons in contact with affected spend a single prophylactic treatment of skin protivokleschevoy drugs.After treatment, the patient many guidelines recommend treatment of all things and linen, which contacted the patient (special sprays, wash in hot water). In accordance with the data on survival itch mites in the environment, but also due to the extremely low probability of transmission through scabies household items (indirect contact transmission path), these recommendations are discussed in each particular case. The latest guidelines do not recommend treating mattresses, upholstered furniture and carpets; bed linen and underwear should extend into the hot water, if from the moment of its use is less than 48 hours.

Important! Contrary to popular belief scabies is not associated with poor hygiene. Itch mite is not susceptible to water or soap. When taken daily shower / bath number of ticks and the probability of infection is not reduced.

Diagnosis of scabiesThe diagnosis of scabies is placed on the basis of clinical symptoms, epidemiological data, data of laboratory examination methods. Laboratory confirmation of the diagnosis is especially important when the erased clinical picture. The following methods of laboratory confirmation of the disease:1. Traditional mite extract the needle from the blind end of the itch stroke, followed by microscopic parasite. This method is not very effective in the study of old dilapidated papules.2. The method of thin sections sections stratum corneum in the course of scabies microscopy reveals not only a mite, but his balls.3. The method of layering scraping of the field blind end scabies progress until the blood. With subsequent microscopic material.4. Method of preparation of alkali skin, application to the skin with an alkaline solution, followed by aspiration matserirovanoy skin and microscopy.In each case, when the patient complains of itching, should first rule out scabies, especially if there was an itch and other family members, or organized groups.Finding itch moves reliably confirms the diagnosis. For a complete confirmation of the diagnosis it is recommended to open the itch move scalpel covered oily substance carefully protsarapyvaya blade along the horny layer of skin itch stroke. These scrapings are placed on a slide and mikroskopiruyut. The best results are obtained with scrapes, "fresh", not combed itch moves to Interdigital spaces of hands. Although this method has 100% specificity, the sensitivity is low.Potassium hydroxide dissolved allows keratin, promoting better detection of mites and eggs, but the dissolved excrement mites, which also have diagnostic value.Itch moves are easier to detect if the paint over the skin with tincture of iodine - the moves are visualized in the form of strips of brown color on a background painted in a light brown color of healthy skin. Abroad for this purpose using the ink.Videodermatoskop at a magnification of 600 times itch moves can detect almost all cases.Due to the fact that the mites can be detected not always, a number of authors proposed the following practical approach to the diagnosis: the diagnosis of scabies is set with a papulovezikuleznoy rash, pustular elements and itching (especially enhanced during the night), and with a positive family history.

 Treatment of scabiesTreatment of patients with scabies is aimed at the destruction of the pathogen using acaricides (skabitsidov) .Lechenie scabiesGeneral rules for the treatment of:Experience shows that when there is no recurrence of scabies, causes the resumption of the disease are reinfestation from untreated contacts in the outbreak, or is it finished the cure of the patient in non-compliance with treatment regimens, partial treatment of the skin, reducing the duration of therapy.- Treatment should be carried out solely under the supervision of a physician;- Treatment of patients living together should be carried out simultaneously;- It is necessary to strictly adhere to the circuit treatments, painted in the instructions to the drug or prescribed by a doctor;- The product is applied to the whole body except the face and scalp, and children up to 3 years, and we must handle these areas;- It is important to cut your nails short and thickly applied drug under them (by scratching eggs under the fingernails accumulate mites);- Rubbing hands made any preparation, due to the high number of burrows on the hands. If the crotch and groin densely covered with hair, the drug is better to rub the brush;- Treatment should be carried out in the evening, due to the nocturnal activity of the pathogen;- Wash the patient is recommended before and after treatment, when the patient may need medication to wash each morning, while its exposure to the skin should be not less than 12 hours, including all the night period;- Change of underwear and bed linen is carried out at the end of a course of therapy;- Children, students, soldiers, and so on. N. Desired 10-day quarantine,- After 2 weeks, the doctor recommended re-examination, to address the issue of re-treatment.If all family members ill with scabies and persons living with patients in the same room subject to preventive treatment. If in an organized team at the same time there are more than three cases of scabies, preventive treatment is carried out to all the staff. Children and students are not allowed in organized children's groups and schools for the period of treatment.Evidence-based clinical trials on the comparative effectiveness of drugs skabitsidnyh currently small. Therefore, in different countries, preferences vary drugs.For example, in the US, UK and Australia, in most cases applied a cream with 5% permethrin. In developing countries, and Russia is the main means of low-cost water and soap suspension or ointment benzyl benzoate (10% or 25%, in Russia 20%). It is much less used in the world monosulfiram (25%) malathion (5%), lindane (0.3-1%), krotamion (10%). In recent years, very popular in Russia, it uses the French drug Spregal. In the poorest countries still using sulfuric ointment. A new revolutionary treatment for ectoparasites (especially forms of Norwegian scabies) became ivermectin.

A list of some drugs against scabies:- Benzyl benzoate;- Pyrethrins and pyrethroids;- Spregal;- Lindane;- Krotamion;- Sulphuric ointment (5-10%);- Ivermectin.After the complete destruction of the itch mite, and some elements of the rash may persist for a few weeks (especially nodules persist for a long time), which is due to immuno-allergic nature of itch rash. To facilitate these symptoms your doctor may prescribe antipruritic, antihistamines and corticosteroids.

Note the treatment of pregnant womenIn the US and Europe, pregnant women are not recommended to treat type Spregal drugs, limited prescribed benzyl benzoate, appointed without restrictions only permethrin. In Russia, on the contrary - mostly prescribed to pregnant and benzyl Spregal while permethrin (medifoks) according to domestic counter-instructions.

Treatment of folk remedies for scabies- One teaspoon of turpentine is thoroughly mixed with two tablespoons of butter and the resulting mixture was treated the affected skin, scabies Treatment folk remedies- One tablespoon of celandine juice mixed with 4 tablespoons of petroleum jelly and the resulting mixture was treated skin;- The tar is applied evenly on the affected skin. After three hours, washed with warm water tar;- If it is necessary to grind freshly scabies yellow "buttons" tansy, and this mass of grated lubricate the skin affected by scabies. Sometimes two or three of such procedures is enough to get rid of the sores;- Pour in the enamelware evening 0.5 liters of water 1 tbsp crushed leaves of rue, bring to a boil and immediately remove from heat. After 30-40 minutes, drain, and then lubricate the decoction of the whole body. Wear clean, ironed clothes, ironed bed and go to sleep. Repeat the procedure every night until recovery;- Mix 1 tsp pharmacy with 1-2 tablespoons of turpentine pork lard and boiled linseed oil and greased regularly this place rash ointment to its complete disappearance;- Dissolve in a pot with warm water soap so as to obtain large cap suds, moisten the sponge in the solution and rub it the patient's body so that the skin surface was a layer of soap. After 30 minutes, rinse with warm water and all well processed problem areas ointment made of 1 part by weight of potassium carbonate (potash), 2 parts of sulfur powder pharmacy and 1/8 portion of the inner melted lard. All components of the mix until smooth. If after a few hours the body will begin to itch severely, it is necessary to wash off the ointment with the patient's body with warm water and put on a clean linen;- If your body has traces of scratching, it is necessary to use sulfuric ointment, made from 1 part by weight sulfur powder and 4 parts of lard. Treating the body with this ointment, 2 times a day, always after a bath;- Brew (Brew it!) In an enamel pan 6-8 kg of salt and pour the broth into the tub with water temperature 37-38 ° C. Soak in a solution of at least one hour, and came out of the bath, do not wipe, and obsohnite. Carry out the procedure on a daily basis to cure;- A mixture of chicken manure with tar treats scabies. Components must be well prepared and rubbed ointment for the night grease the diseased places. It is advisable not to wear underwear. In the morning the body thoroughly cleaned;- When scabies rub chalk, sift it through a fine sieve and this "flour" good place lubricate rash. Scabies is passed;- When skin diseases, especially scabies, it is necessary to wash a strong decoction of the root elecampane as long as the body clears. Do not expect instant healing and patient being treated, and soon will come improvement;- Rub soap on a grater and soften, add water. Stir and put on a slow fire. Constantly stir. Once the mass is smooth, remove it and add the average grated onion and a clove of garlic. Let cool, roll into balls and wash it daily with soap.