Scabies: Symptoms and Treatment
- Features of the life cycle of scabies mites
- Symptoms of Scabies
- Diagnosis of the disease
- Scabies treatment
Scabies is a skin disease caused by the parasitism of scabies mites (Acarus scabiei) in the superficial parts of the skin.
Scabies has long been known. Mention of it can be found in Egyptian parchment. In ancient China and Babylon, this disease was also well known. Ancient Greek Aristotle even gives in his writings a description of the “smallest animals” in the bubbles of rashes on the skin of sick people.
At the present stage, the greatest prevalence of this disease is observed among socially unadapted groups of the population. Its outbreaks are observed in disadvantaged regions of the world, where there is a massive migration of the population under the influence of natural disasters and military actions.
In regions that are prosperous in this sense, no one is immune from this disease either. Thus, the appearance of one infected person in a group of people united for some time (from a trip in a bus, to a long stay in one room - a kindergarten, school, orphanage) already suggests the presence of a potential focus of the disease. The greatest risk of becoming ill in the age ratio is in youths (25-35%). This is due to the greatest contact activity in groups both during training (school, technical school, institute), and after it (informal connections, courtyard, boarding school, dormitory).
The increased risk of scabies contributes to the active migration processes of socially vulnerable groups in the context of globalization of the surrounding world. Some risk is borne by mass tourism, especially in extreme destinations, to exotic countries of the world, where this disease is quite common.
Features of the life cycle of scabies mites
An adult female of a scabies mite of about 1/3 mm. Their photo is on the right. Males are about 1.5 times smaller and have no significance in the clinical picture of the manifestation of the disease.
Like all insects, in its development itch mites pass through the larval and adult stages. After fertilization, the female takes root in the superficial part of the skin (epidermis). Feeding on the epidermis, it moves, making moves in it, where, in addition to the products of its vital activity, it leaves eggs. In one intraepidermal course, 3-4 fertilized eggs can be identified at different stages of development. Above the site of laying females make holes to facilitate the release of offspring on the surface of the skin. On the skin, the larvae, spreading around, penetrate into the hair follicles (hair roots), under the keratinizing scales of the skin, into various elements of the rash (especially vesicular). There they undergo a transformation, bypassing the intermediate stages, immediately into adult, mature individuals of the tick. Mating occurs on the human skin, after which females invade the epidermis, while males scrape off, combed, and microscaloculate the skin and die. The average life of the female is 6-8 weeks, during which she lays about 60 eggs. It is estimated that the potential breeding of adult ticks from one female in three months can amount to 150 million individuals.
Removed from the skin, in the environment at room temperature, itch mites can maintain their viability for about a week. Under less favorable conditions, females live for about three days, and the larvae - about two.
Symptoms of Scabies
Scabies is of the following types:
- Typical, classic.
- Without scabby moves.
- Norwegian scab.
- Scabies "clean", or scabies "incognito."
- Complicated scabies.
- Scabious lymphoplasia of the skin.
Typical (classic) form of scabies
The main sign that attracts attention, is a strong, obsessive itching. Itching is a reaction of the body to irritation by tick life products. It is the response of the immune system, one of the parts of the external manifestation of which becomes the sensation of itching, that restrains the unrestrained multiplication of the parasite, the outcome of which could be death. With particular force, sometimes even depriving sleep, itching manifests itself in the evening and at night. This is due to the greatest activity of the female tick at this time. The main occupation of it during this period is the construction of intraepithelial passages.
Scabies moves are the most characteristic sign of scabies. From each stroke, the female gnaws one or two branches, making several outlets in them. Fertilized eggs are laid in each of the tribes. Further, it continues to move in the main course. With the onset of morning and until the middle of the day, the activity of the female drops sharply, and at the same time in all individuals.
When exfoliating the skin, old passages are gradually found out in the form of whitish lines, like surface scratches left when the needle is held over the skin. Figures have their own periodicity and repetition, according to which one can judge about the daily movement of a turn.
The length of the diurnal stroke rarely exceeds 5 mm., And over the course of her entire life, the female passes about 3-6 cm. Theoretically, it is possible to identify scabies on any part of the body, but their most likely location is in areas with thickened epithelium. These areas are the skin of the hands and feet. The thickness of the epidermis present here allows the larvae to hatch from the eggs long before the stumping layer is rejected. In addition, to maintain the life cycle does not require too high temperature of the skin.
The body's reaction to the introduction of a tick becomes the appearance of a rash in the form of small red tubercles (papules) 1-2 mm in diameter, towering above the rest of the skin, sometimes having vesicles (pustules) at their top filled with liquid. The first rash of this type can be found above the site of the introduction of the mite into the skin. Photo rash with scabies you can see on the right.
The number of papules, as a rule, depends on the number of ticks introduced. Rashes can be initially multiple and “pour” after the appearance of new mature individuals.
A scabrous rash, along with scab-like passages, can most often be found in the interdigital folds of the hands and feet. You can also identify them on the flexor surfaces of the wrist joint, along the lateral surfaces of the fingers, in the armpits in front, in the umbilical region, on the inner surfaces of the thighs, buttocks. As an option, there is an arrangement of mange moves in men on the skin of the penis, in women - around the nipples.
For children, due to the peculiarities of the structure of the skin, the most characteristic localization of rashes and strokes on the palms and soles.
With severe itching and subsequent scratching, the rash, due to the addition of infection, takes a pustular appearance, with yellow crusts. Perhaps the addition of inflammatory skin diseases, up to boils and carbuncles. Perhaps the addition of erysipelas and dermatitis.
Other symptoms of typical scabies
In addition, a long history of observations of scabies allowed us to identify a number of characteristic symptoms by the authors, allowing to differentiate this disease from skin appearances of other diseases:
- a symptom of I. A. Gorchakov-Ordi (appearance of pustular rash and pustules on the extensor sites of the elbows, with the presence of crusts with staining of blood);
- Michaelis symptom (appearance of bloody crusts in the interglacial area against the background of enlightened skin areas);
- Syesary symptom (probing of the parasite and scabby moves in the form of slightly perceptible elevations during palpation of the proposed site of tick localization, determined in the presence of single skin elements of the rash).
Regional lymph nodes may also be enlarged.
Scabies without intraepithelial scabies
Extremely rare. In these cases, the infection is carried out not by a mature individual, but at the stage of development of the tick in the larva stage. The rarity of this form of scabies is explained by the fact that in order to retain the parasite on the skin surface, it is necessary to have a developed gnawing mouth apparatus, which the larvae do not yet have. Individuals that were able to resist and penetrate the hair follicles cause a pronounced immune response to the stimulus. There is a severe itching and rash of an allergic nature, not only in those places where the larva has infiltrated, but throughout the body. Accordingly, until the larva matures into the mature individual of the female (and sometimes it takes up to two weeks) and does not penetrate the epidermis, itch cannot be detected in the scabies in places of the rash.
Named in this way because it was first described in Norway in patients with leprosy (leprosy) in the middle of the 19th century. This is the most contagious and malignant in its course form of scabies. Occurs in individuals with persistent background depression of the immune system for various reasons. For example, after undergoing chemotherapy for oncological diseases, with hormone therapy, part of serious diseases with corticosteroids. Patients with Down syndrome, HIV-infected people have a risk of developing severe forms. Violations of the sensitivity of the skin, observed with paralysis of various etiologies, some other diseases, congenital features of keratinization of the skin can also contribute to the transition of the classic form of scabies to the Norwegian.
- A variety of rash elements that have a confluent nature, from spots, to blisters, the presence of ulcerated cracks in the skin.
- The appearance of crusts of various shades of yellow and brown. Increasing in thickness and merging, they can form a kind of "shell" over areas of the body.
- In the crusts, when they are studied, a huge number of ticks are revealed at different stages of their life cycle. Sometimes, their number reaches 200 per cm².
- It is possible to identify the parasite on the nail plates, which, under the influence of the fungal flora, thicken and become friable, convenient for the tick to inhabit and develop its offspring.
- Adherence to the described picture of extensive pustular skin lesions, furunculosis, due to the addition of a secondary infection.
- There is a long rise in temperature.
Scabies "clean", or scabies "incognito"
- This form is characterized by the smoothness of the classical clinical picture due to professional (doctor, pastry chef, cook, etc.) and due to personal characteristics - cleanliness.
- New moves are not actually formed, the manifestations of itching are minimal, and individual elements of the rash are due to allergies to detergents.
- The spread of the disease to other parts of the body due to the constant mechanical removal of mature individuals and larvae during washing does not occur.
- Itch moves are single.
The danger of patients with this form of scabies is that, because of their obvious cleanliness outside, no one regards as the primary source of outbreaks of the disease. Yes, and the infected himself does not consider himself ill with any disease.
However, complete self-healing in such cases does not occur, since the maximum release of mites to the skin occurs at night, when the unsuspecting patient is asleep and does not perform the usual ablution.
In this form of the disease, there will be a clinic of complications in the form of dermatitis, furunculosis of the skin, erysipelas, abscesses, and soft tissue phlegmon. Occasionally, the disease can occur in the form of a light urticaria, as a complex response of the body to a foreign antigen. This will be the main focus of treatment.
Accordingly, the disease will last for a long time, and the patient will retain its danger to others, as a permanent source of scabies.
Manifested by the appearance of a rash in the form of a nodule (papules) elongated in small lines of a blue-purple color. They appear in the projection of scabby passages and are most often observed on the inner surface of the thighs, on the scrotum, buttocks, elbows, on the mammary glands of women. These towering reddening of the passages are due to an allergic reaction and the close presence of lymph nodes in these areas. This is confirmed by the appearance of this type of rash in the same places during repeated infection with scabies.
This is an infection of scabies, parasitizing exclusively on animals. The difference is that the infection is carried out by the larvae, not by the adult mites, and the disease manifests itself immediately. The introduction is carried out on open skin areas, which is explained by the penetration of the larva into the hair follicle. The parasite does not reach hidden areas of the skin, due to the inability to stay on the surface. When it reaches puberty, the mite either dies or is peeled off the skin. Thus, after a brief itch and rash, self-healing occurs.
Diagnosis of the disease
In addition to the classical clinical picture, it is necessary to confirm the presence of the parasite at different stages of its development. This is achieved by extracting it with a needle.
In addition, under a microscope, surface sections of the skin (epidermis) obtained by the layer-by-layer method and thin-section method are investigated using express diagnostics using 40% aqueous lactic acid solution.
It is carried out with the help of anti-scour agents, the choice of which has recently been quite large.
The difference from the previous generation of such funds was the high rate of onset of the therapeutic effect in the absence of any side effects.
The most commonly used spregal, benzyl benzoate.
The preparations are applied to the whole body in the evening, rubbing it carefully, especially paying attention to the characteristic habitats of the parasite. The drug remains on the skin all night, and in the morning the patient is thoroughly washed. To improve the effect, it is recommended to repeat this procedure in 2-3 days.
In complicated cases, antibiotics, antihistamines and hormonal ointments are connected to the described therapy. In these cases, treatment should take place under the direction and supervision of a physician.
- Urticaria: photo, symptoms, treatment
- Deprive a person: photo, symptoms, treatment
- Urticaria in adults: photo, symptoms, treatment
- Streptoderma: symptoms, treatment
- Urticaria in children: photo, symptoms, treatment
- Licolor versicolor: photo, treatment
- Red spots on the body: reasons for what to do and where to go?