Scabies mites. Tick-borne dermatitis, features of manifestation, methods

Dermatitis is called inflammatory diseases skin. Moreover, inflammation can be provoked by the most for various reasons, including insect bites. Thus, tick bites cause tick-borne dermatitis in humans. Animals can be carriers of ticks; in addition, you can “meet” ticks while walking in the park or during a trip to nature.

With the arrival of spring, many people strive to go out to relax in nature or at least take a walk in the park. And often during such walks there is an “encounter” with ticks. These insects belong to the arthropod family; their bite can cause the development of allergic dermatitis. In addition, ticks are carriers dangerous infections, so you need to try to protect yourself from their bites.

Where can you get a bite?

You can “encounter” a tick not only in the forest belt, but also at home. Domestic animals are often carriers of these insects. Unlike the scabies mite, forest dwellers do not form passages under the skin, they simply drink blood. But during a bite, insect saliva gets into the wound, which can cause the development of allergic reaction.

Most often, ticks bite people while walking in parks and forest plantations. Insects live on grass and bushes; when a person passes by, the tick jumps onto clothing and, moving along the body, selects the most comfortable spot for a bite.

Grain mites live on cereal crops. Therefore, the risk of developing dermatitis is greater in people working in agriculture, as well as in grain warehouses and elevators.

A common symptom that is observed in all patients with tick-borne dermatitis is a profuse rash and severe itching. In addition, there is always a risk of secondary infections and development purulent process. But there is also specific symptoms, which are inherent in dermatitis caused a certain type insects

For example, with dermatitis caused by shoe mite bites, rashes appear on the lower half of the legs. If the cause of irritation is grain mite bites, then the appearance of small red pimples that look like nettle burns is noted.

With tick-borne dermatitis, the skin in those parts of the body where the insect bite was made is affected. And since ticks prefer to bite in places where the skin is thinnest, rashes are most often observed in the following areas:

stomach;
armpits;

folds in the groin;
area under the knees and on inside elbows.

Advice! Tick bites can cause not only allergic dermatitis. Insects are carriers of such serious diseases as Lyme disease, Q fever, rickettsiosis, etc.

Who is at risk?

The areas where ticks spread can be divided into two groups. The first will include household ones, these include the lower floors of residential multi-storey buildings, private houses, and dachas. The second includes industrial foci; in such foci the number of ticks is always greater. Such outbreaks include granaries, poultry houses, zoos, as well as warehouses, shops and markets.

Risk groups are formed depending on the type of insect. As already mentioned, grain mites often bite workers in agriculture and granaries. People who work in poultry farms or keep poultry at home are more likely to be bitten by bird mites.

Those most at risk of contracting rat tick-borne dermatitis are workers in vivariums where rodents are bred, as well as residents of the private sector, workers in warehouses infested with rats, etc. The risk group also includes forestry workers, as well as people who prefer to spend their leisure time in nature .

Therapeutic measures

Before starting treatment for tick-borne dermatitis, it is necessary to make an accurate diagnosis. The fact is that the symptoms of this disease are similar to other dermatoses. And the use of medications used to treat other diseases for tick-borne dermatitis will be ineffective.

In addition, for successful treatment it is necessary to exclude the provoking factor, namely, to exclude the receipt of new insect bites. Treatment is prescribed individually, depending on the degree of damage to the skin and general condition.

Methods are also widely used traditional medicine. Traditional healers It is recommended to use such means as:

decoction of succession herb;
infusion of chamomile flowers;
propolis tincture;
sea buckthorn oil;
rosehip oil.

These drugs effectively relieve itching and accelerate skin healing.

Preventive actions

Tick bites can cause a lot of trouble for a person. And tick-borne dermatitis is not the most serious consequence"meeting" with an insect. Ticks are carriers of dangerous infections, so measures should be taken to prevent insect bites.

Basic preventive measure is to avoid contact with insects. Therefore, the following activities are recommended:

carrying out deratization - cleaning premises from harmful rodents. To perform this work, it is better to contact specialists. The owners themselves should try to block all detected rodent passages. The holes are covered with a solution to which broken glass is added;
regular disinfestation (treatment against insects) of premises where poultry and livestock are kept;
pet owners need to regularly inspect their pet’s coat, as well as special treatment of the bedding on which the pet sleeps;

When planning a walk in the forest, you need to dress “correctly”. The tick does not bite through clothing, so you need to ensure that almost the entire body is protected. Pants legs should be tucked into high socks, jacket sleeves should end with tight-fitting cuffs;
It is very important to protect your head and neck, since ticks often fall from above (from trees or bushes);
Be sure to get a product that repels ticks. They should treat not only open areas of the body, but also clothing, as well as a tent and sleeping bag;
You should choose the right places for picnics and rest stops. It should be remembered that in dry clearings, well lit by the sun, there are much fewer ticks than in shady areas;
upon returning from a walk, inspect your clothing and skin;
It is recommended to remove clothing outside residential premises; it should be shaken off well and inspected for insects. Pay special attention to seams, pockets and folds.

So, the manifestations of tick-borne dermatitis are the consequences of insect bites. The nature of this disease is allergic. That is, rashes and itching occur due to an allergic reaction to substances contained in the saliva of insects. To avoid illness, it is worth taking precautions against bites.

When a person is infected with scabies from animals, it is called pseudoscabies, or mite-borne dermatitis. The most common source of infection is dogs, but there may also be pigs, horses, sheep, goats, rabbits, foxes and other animals.

The incubation period ranges from several hours to 2 days. Female mites, penetrating into the epidermis of human skin, cause itching, but do not form burrows or lay eggs [Lange A. B. et al., 1985]. At the site of penetration, urticarial, papular, and papulovesicular elements usually appear. The disease is not transmitted from person to person and self-healing can occur when the source of infection is eliminated. Ticks are difficult to detect, and only females are detected.

The diagnosis of scabies is based on clinical manifestations, epidemiological data and laboratory results. Confirmation of the diagnosis of scabies laboratory method seems especially important in cases where the diagnosis of the disease is difficult.

The traditional method of extracting mites with a needle from the blind end of a typical scabies burrow, followed by microscopy of the mite placed on a glass slide in a drop of 10% sodium hydroxide, makes it possible to confirm clinical diagnosis. However, this method is ineffective in the presence of old dilapidated passages, vesicles and papules.

The method of thin sections of the stratum corneum of the epidermis in the area of the scabies tract or vesicle, followed by treatment with 20% sodium hydroxide for 5 minutes and microscopy makes it possible to detect not only the mite, but also its eggs.

The method of layer-by-layer scraping with an eye spoon of fresh elements until blood appears, placing the material in a drop of 20% caustic alkali with glycerin in equal volumes and microscopy after 10-20 minutes.

A method of alkaline skin preparation, which consists of applying 10% alkali to scabies on the skin, scraping off the macerated epidermis with a scalpel after 2 minutes and microscopying the preparation in a drop of water. TsKVI M3 of Russia together with the Department of Entomology of Moscow State University. M.V. Lomonosov developed and put into practice a new method for laboratory rapid diagnosis of scabies using lactic acid [Lange A.B. et al., 1984, 1985].

The method is based on the ability of lactic acid to quickly clarify the epidermis and mites in the preparation, which makes it possible to diagnose the disease with great accuracy. In addition, lactic acid does not crystallize, does not dry out, well loosens the stratum corneum of the epidermis before scraping, prevents the development of pyogenic complications and removes the remains of dyes used to stain scabies mites to identify them.

For laboratory diagnostics 40% used water solution lactic acid. One drop of lactic acid is applied to the scabies element (scabies tract, papule, vesicle, crust, etc.). After 5 minutes, the loosened epidermis is scraped off with a sharp eye spoon until capillary blood appears. The material is transferred to a glass slide in lactic acid, covered with a coverslip and microscopically examined.

The result is considered positive if the preparation of the contents of the scabies tract reveals an adult female mite or even only eggs, empty egg membranes or individual larvae and fragments.

House dust is considered by many to be the cause of allergies, but few people know that negative reactions For most people, it is caused by only one component - dust mites.

Allergy to dust mite provokes development bronchial asthma in future.

Features of a dust mite

A dust mite cannot be seen with the naked eye; the size of this arachnid does not exceed 0.5 mm. Ticks house dust are synanthropic organisms, as they feed on desquamated epithelium of humans and animals and food debris. Their lifespan is about two months, during which time the female tick manages to lay 60 or more eggs, thus leaving numerous offspring. Not only excrement has allergenic properties, but also the chitinous cover of house dust mites, so even dead mites can cause a negative response immune system in a child and an adult.

The ideal habitat for dust mites is a room with a temperature of 20°C - 25°C and high level humidity. Maximum amount House dust mites are found in the thickness of mattresses, fillings of pillows and blankets, carpet pile, furniture upholstery, and children’s toys. Some types of these mites (flour mites, barn mites or common hairy mites) live in food products - flour, seeds, dried fruits, cereals.

Signs of a dust mite allergy

In many cases, an allergic reaction to a mite manifests itself as rhinitis. The symptoms of this condition are as follows:

sneezing (can be repeated, in the form of attacks);
watery or thick mucous discharge from the nasal passages;
itching and burning in the nose;
nasal congestion.

U infants allergic rhinitis is particularly difficult. At this age, the mucous membrane of the child’s nasal passages is richly vascularized, so its swelling develops quickly. Breathing through the nose becomes very difficult, which creates difficulties when feeding. Thus, the symptoms of rhinitis are accompanied by lack of appetite, insomnia and irritability of the child.

In addition, house dust mites can cause the development of conjunctivitis, dermatitis and asthma. In such cases, the following symptoms may occur:

lacrimation and redness of the whites of the eyes;
pain in the eyes;
poor tolerance to bright light;
skin itching;

skin rashes localized in the face, neck, armpits, elbows and knee joints, perineum, scalp of the child;

inspiratory dyspnea (difficulty breathing), wheezing, paroxysmal cough, accompanied by the discharge of a small amount of viscous transparent sputum.

Rarely, an allergy to dust mites is accompanied by the development angioedema. If symptoms of this condition occur (hoarseness, feeling of suffocation, swelling of the face, upper or lower limbs) you must consult a doctor immediately.

When the cause feeling unwell it was a dust mite that served as the source, then they attract attention following features course of allergies:

remission outside the home;
relapse upon contact with big amount ticks (during cleaning or sleeping at night);
seasonality of exacerbations of allergies (August - October), associated with the active reproduction of mites;
exacerbation in autumn and winter period caused by the child being at home and refusing to ventilate the rooms;

concomitant feather allergy, as well as food allergy for seafood (crabs, shrimp, crayfish).

Most often, allergic reactions to house dust mites occur in children. This is due to the increased reactivity of the child’s immune system. In addition, sensitization occurs faster in children because they have more contact with the mite (crawl, play with soft toys).

Treatment

When do they arise? obvious symptoms allergies to mites, you cannot do without the use of medications. Systemic treatment implies reception antihistamines(“Claritin”, “Semprex”, “Astemizole”). In some cases it is necessary local treatment. To eliminate allergy symptoms, the doctor prescribes the following antihistamines:

nasal spray "Histimet" for rhinitis;
Allergodil eye drops for conjunctivitis;
Soventol gel, Fenistil or Zyrtec ointment for dermatitis.

At severe course an allergic reaction to a house mite will require the use of nasal and eye drops With vasoconstrictor effect(“Sanorin”, “Afrin”, “Octilia”, “Vizin”), as well as creams and ointments with a hormonal component. Treatment with these drugs should be brief, since long-term use they cause serious adverse reactions. Many of them are contraindicated for children, pregnant and lactating women. It is highly undesirable to use such drugs without first consulting a specialist, especially if a child is being treated for a mite allergy.

To alleviate rhinitis and dermatitis in children, you can use safe means: nasal spray "Aqua Maris", "Quix" or "Aqualor", cream "Losterin", "Videstim" or "Desitin". Auxiliary treatment includes vitamin therapy, warm baths with decoctions medicinal herbs(chamomile, sage, calendula). Special sprays are produced that destroy dust mites; they are intended for treating rooms and objects. Their use allows you to reduce contact with ticks and make drug treatment more efficient.

To prevent exacerbations of mite allergies, desensitization can be done. The essence of this procedure is that a dust mite extract is introduced into the body. Typically, injections are carried out at intervals throughout the year, gradually increasing the dosage of the injected mite extract. As a rule, such treatment after some time leads to a decrease in the frequency and severity of relapses. Specific immunotherapy has contraindications and some risks, so it is allowed only after a complete examination.

Preventive actions

Unfortunately, it is almost impossible to completely eliminate contact with dust mites, since they are ubiquitous. However, in order to reduce the frequency of exacerbations and alleviate the symptoms of the disease, it is enough for many to do prevention.

Remove carpets that you can do without (especially if they have thick and high pile).
Reduce the amount of furniture with fabric upholstery, replacing it with furniture trimmed with leather or its imitation.
Ventilate the rooms several times a day.
Do wet cleaning every day, paying attention Special attention hard-to-reach places where it accumulates greatest number dust.
Buy a vacuum cleaner with a water filter.
Use a mask or respirator when cleaning.
Get rid of pillows and blankets filled with down or feathers, and instead use products with synthetic fillers.
Periodically beat out and dry pillows and blankets.
Change bed linen at least once a week, dry it thoroughly fresh air.
Take a shower and wash your hair daily.
Remove the child from the room Stuffed Toys, and wash the remaining ones and dry them in the fresh air once a month.
Buy a hygrometer (a device that measures air humidity) and make sure that the humidity in the room does not exceed 40 - 50%.
Use dehumidifiers (with caution in case of bronchial obstruction).
Purify the air using air conditioners or special purifiers.
Refrain from eating food outside the kitchen, crumbs are great nutrient medium for a tick.

To clear Airways It is advisable to rinse the nasal passages to remove ticks and their excrement. To do this, use a special saline solution. You can make it yourself, a liter is enough boiled water dissolve a teaspoon of table salt.

The main host of the rat mite is the gray rat, but in urban conditions it is possible to reproduce and feed on house mice. Distinctive feature, which determines its epidemiological significance is its ability to feed on humans, as well as on domestic animals - dogs and cats. Ticks spend most of their life outside the host's body. Indoors, they are distributed unevenly and form clusters in places regularly visited by rodents (at utility lines, on floors and walls near heating devices, near rat holes).

Mass reproduction of rat mites and the emergence of KKD foci in urban conditions ( warm room, abundance of food) occurs throughout the year. But greatest number outbreaks are observed in the spring, which is associated with to a large extent, with the biological features of the gray rat.
There are 2 types of foci of rat tick-borne dermatitis: domestic and industrial.

Domestic fires are usually confined to the first and second floors of residential buildings. Features of the clinic in domestic outbreaks are associated with a lower number of ticks, their distribution in apartments and the family’s lifestyle. The defeat occurs at any time of the day, most intensely in people who stay in an apartment for a long time (pensioners, disorganized children, unemployed).

Production centers are objects associated with the keeping and breeding of animals (vivariums, zoos, laboratories), objects associated with processing and storage food products(meat processing plants, markets, food depots, shops, etc.), office premises for administrative and production purposes.

Under production conditions, CCD acquires all the characteristics occupational disease: single etiological factor, widespread lesions, uniformity of manifestations, predominance of rashes in places of contact with contaminated objects of labor, improvement clinical manifestations on weekends, complete resolution of rashes during vacations, resumption of illness upon returning to work. Regardless of profession, all persons working in the outbreak are affected.

Thus, industrial outbreaks are generally characterized by a high number of rats and ticks and large groups of people being affected at the same time. Due to the high number and frequent attacks of ticks on people, the disease is acute.
When a rat mite attacks and feeds on a person, it causes dermatitis, an inflammatory reaction of the skin to blood sucking. The appearance of the first symptoms is preceded by a crawling sensation on the skin, a burning sensation, then itching appears. Excruciating itching, aggravated by scratching, touching clothing and hot water treatments. Itching is not associated with certain time days, but depends on the time a person spends in a room infested with ticks. When you stop contact with mites, the itching subsides after 7-10 days. Rashes appear in places where ticks suck blood. The polymorphism of the rash depends on the number of rat mites, the frequency of attacks and individual reaction patient's skin.
Ticks can suck blood anywhere skin, but are more striking top part body in places where clothing fits tightly (straps, shoulder straps, belt, collar), where rashes are grouped. Ticks prefer to feed in places with thin and delicate skin.

Treatment of KKD aimed at eliminating itching and inflammatory reaction, which arose in places where ticks sucked blood. It is only effective in eliminating rat mites. Antihistamines and desensitizing drugs are prescribed internally, and aniline dyes are prescribed externally.
The system of measures for the prevention and elimination of outbreaks of KKD includes: examination of the outbreak, decontamination measures, deratization measures, registration of the outbreak.

Indications for examining the outbreak are: the presence of rat mites in residential premises, basements, warehouses, etc.; identification of patients with KKD and foci of mite reproduction, as well as treatment of patients with dermatitis unknown etiology if CCD is suspected.
To identify ticks indoors, the following is used: the method of visual detection of ticks in places regularly visited by rodents; They collect dust samples from certain places in a room infested with mites, followed by studying the samples in the laboratory.
Treatment of outbreaks from rodents and ticks should be carried out after a preliminary examination by a disinfectant doctor (or a disinfectant instructor), no later than 2 days after receiving complaints about tick bites. In case of difficulties with identifying ticks, you should seek help from an entomologist of the Federal State Institution "Center for Hygiene and Epidemiology in Moscow" or in the branches of the Federal State Institution "Center for Hygiene and Epidemiology in Moscow" in the joint-stock company.

All premises where KKD patients were identified and rat mites were found are subject to decontamination. IN mandatory treat places of penetration and movement of rodents indoors: utility lines, communication channels, baseboards with adjacent sections of the floor and walls to a height of 1 m from the floor surface, as well as places of possible accumulation of ticks - heated areas of walls and floors near heating devices and thermal communications. If there are animals, special attention is paid to places where they feed and rest (bedding, sofas, chairs, tables).

Deratization measures include the fight against synanthropic rodents on objects when rat mites appear there, control over the number and distribution of rodents, identification and timely sealing of rat holes in residential premises, monitoring the sanitary and technical condition of objects (especially food) that attract rodents.

For personal prevention purposes When working in a laboratory, in vivariums, or in areas of mass tick reproduction, it is advisable to use repellents (“Biozaschita”, “Acroftal”, “Ftalar”, etc.)

Normative base:

1. Guidelines on organizing the fight against rat mites M., 2001.
2. Methodological recommendations for the control of rat mites, prevention and treatment of rat mite dermatitis. M., 1993
3. SP 3.5.3.1129-02 “Sanitary and epidemiological requirements for deratization”
4. SanPin 3.5.2.1376-03 “Sanitary and epidemiological requirements for the organization and implementation of pest control measures against synanthropic arthropods”
5. SanPiN 2.1.2.1002-00 “Sanitary and epidemiological requirements for residential buildings and premises”

Dermatitis is an inflammation of the skin, which is accompanied by severe itching. Dermatitis of this type begins to develop in the human body when a tick bites. Usually this insect lives either in the fur of domestic animals or on the body of wild animals. The disease can be caused due to exposure to grain, pasture, and shoe mites on the skin.

An insect bite can cause severe skin itching. The main difference between tick-borne dermatitis and ordinary scabies is that in the first variant the insect does not make an itch in the area of the stratum corneum of the epidermis.

Tick-type dermatitis can be caused by different types of mites. Rat tick dermatitis is caused by the bite of a tick called Ornithonyssus bacoti. This insect is usually classified as a gamasid mite. These ticks feed on certain types of animals, which include rats, mice, dogs, and cats. At the same time, they do not shun consumption human blood. The occurrence of murine tick-borne dermatitis is characterized by tick bites separate variety, which lives in the fur of house mice.

The disease can manifest itself due to the activity of shoe mites, which live in boots, shoes and any other types of footwear.

If we take into account urban conditions, ticks in such an environment multiply throughout the year, but the main peak of the disease should usually occur in the spring.

Symptoms of tick-borne dermatitis

During the development of tick-borne dermatitis, the skin begins to become covered with profuse rashes, which are accompanied by severe skin itching. In some cases, a secondary infection is added.

In a certain situation, the rash is concentrated in those places that come into contact with living beings or grain. In the event of rat tick dermatitis, the insect bites in the area where the inguinal folds and popliteal folds. Also negative impact may occur on the legs, stomach, and armpits.

Symptoms during the lesion various types insects always appear in the same way, however, there are some differences.

For example, grain scabies is usually characterized by uritric rashes. They're basically blisters. Pink colour, expressed severe itching. They are usually 0.5 centimeters or more in size. Shoe mites usually provoke the development of dermatitis in the area of the legs and feet.

Who is at risk

Tick-borne dermatitis is usually divided into:

Domestic type fireplaces;
Industrial type outbreaks.

The people who most often suffer from tick bites are people who spend a large number of time in the home. These are mainly unemployed, retired people, and children.

Industrial-type outbreaks are usually located in residential premises where there are pets ( laboratory premises, areas of zoos) or where food products are stored and processed (market areas, meat processing plants, store premises).

During the period of tick-borne dermatitis distinctive feature The main risk group is dependence on a specific type of tick, which is the cause of the disease. The occurrence of grain scabies usually occurs in people who engage in rural farming working in warehouses.

If it concerns rat or mouse tick-borne dermatosis, then the risk group is supplemented by those who are engaged in activities related to animals.

Treatment methods for tick-borne dermatosis

Before implementation medical procedures necessary in the right way diagnose a disease to exclude from the list a disease that has a similar set of symptoms. For example, quite similar symptoms has scabies. When the diagnosis is finally established, the first step is to avoid possible contact with the main pathogens of the disease.