Scabies: symptoms and treatment
Scabies is an infectious skin disease, provoked by an itch mite. Scabies, the symptoms of which appear in the form of intense itching and a specific rash, are also often combined with the appearance on the skin of the secondary form of pustular elements. They, in turn, are formed on the skin as a result of infection, which is actual when combing the skin during itching.
Scabies mite, which is the causative agent of the disease, belongs to the class of arachnids (arachnids). The length of females is of the order of 0.5 mm, while they are almost twice as large as males. The parasites mate directly on the surface of the skin, after which the males die (as regards the life span of the females, it is about a month).
Fertilized females affect the stratum corneum of the skin — it is here where they make itch scabs, in which eggs are laid (2-4 pieces each). These larvae later hatch larvae passing through several basic stages of development, after which they already become adults. Separately, we note that keratin of the skin is dissolved by parasites due to the enzymes that make up their saliva. In general terms, creatine is a fibrillar protein that possesses a significant degree of strength, due to the inherent characteristics of them provides a protective function, flexibility and other characteristics of hair, nails and skin. Accordingly, due to its destruction, the formation of itch moves becomes possible.
After hatching, the larvae begin to independently form the scabies within the upper layer of the skin. Further, after 3-4 days, they begin to shed, turning, thus, into protonimph. The next moult in the next 2-5 days will transform them into a tele-image, which eventually, after 5-6 days, develop either in the adult female or in the male. Accordingly, the duration of the tick formation period is about two weeks.
Meanwhile, tick infestation is possible at any stage of its development, despite the prevailing tendency to transfer mainly adult fertilized females.
In the daytime, mites do not show activity. Accordingly, the digging of itch moves occurs in the evening, due to what exactly at this time the main manifestation of scabies — itching — intensifies. At night, females crawl to the surface of the skin, where mating occurs and their subsequent movement to other parts of the body. Remarkably, the displacement along the surface of the warm skin is carried out by them at an approximate rate of 2.5 centimeters per minute, and it is at this time that the most favorable situation for the infection is created.
Life, like the reproduction of an itch mite, is possible only if it is found within the skin. According to the approximate data, in the absence of treatment in the period of three months, the soil is provided for the cultivation by the patient of at least 150 million parasites.
As the reader has already been able to understand, being on the skin of males, females and larvae not only cause itching, but also scratching. As the main reasons against which it is possible to catch a scabie mite, we consider unsanitary conditions, direct contact with an already infected person, violation of the generally accepted sanitary and hygienic norms. Concerning marked contact with a person, it is important to remain vigilant even if there is no confirmation of the disease, and there are only certain assumptions on his account (on the basis of specific manifestations). Separately, it should be noted that the presence of diabetes in a person is also considered as a predisposing factor for scabies.
Symptomatic of scabies is caused by an immune-allergic reaction to the products of the vital activity of parasites that arises from the body. The basis for this reaction determines sensitization — the gradual development of an increased sensitivity of the organism to allergens (to the acting factors, in this case to the noted parasites). The symptomatology appears after sensitization, and this explains the long asymptomatic course of the disease (about four weeks), preceding the appearance of the first signs indicating it, and indicating the primary form of infection. If the case of repeated infection with scabies is considered, then the reaction to the effect of the pathogen is noted within a day after this. Meanwhile, the repeated infection is somewhat complicated, which is explained by the development of protective immunity in the body. If the repeated infection still took place, then the body reveals a much smaller number of parasites.
With regard to such a manifestation as itching of scabies, it is the result of an allergic reaction corresponding to type IV, that is hypersensitivity, manifested in a slowed-down scenario. As can be understood, such a reaction is developed with respect to the excrement of parasites, their eggs and saliva. In frequent cases, itch-induced scratching becomes, as was originally noted, the reason for the attachment to the picture of a bacterial microflora disease, which is streptococci and staphylococci, resulting in the appearance of pustules. Accordingly, the rash that occurs when scabies is polymorphic, which determines the attachment to it of other elements, generally not relevant to the underlying disease.
What is noteworthy, when studying ordinary household dust, which contains household microscopic mites that feed on human epithelium, the same allergens are found, and they act as the basis of such dust.
In almost all cases, infection with this disease is preceded by a prolonged direct contact of healthy skin with the skin of the infected. Scabies in children in many cases develops when infected from sick parents, as well as in collectives, within which other types of transmission path (games, sports, etc.) are provided.
Despite the fact that in the context of many guidelines, the information that is obsolete now regarding the transfer of the pathogen through the use of contaminated household items (bed linen, household items, etc.) is supported in the implementation, experts still consider this variant of infection as The least likely option. As an exception, can be considered in this case except that the Norwegian scabies, in which the body of a sick person is affected by the number of mites counted in several million of their units.
In support of the option regarding direct transmission, an experiment was conducted once. In the course of his 272 attempts to infect scabies when laying volunteers in bed after lifting a scab from the patient, only 4 people subsequently diagnosed the disease against the background of such infection.
The considered features, relevant for the transmission of the parasite, are in its biological qualities:
- itch mite does not show activity during the day; Females crawl out to the skin, as already examined, only by night and by night
- to penetrate the skin, the tick takes about half an hour;
- The tick, when exposed to environmental conditions, quickly dies (for example, death occurs in conditions of 40-80% moisture at a temperature of about 21 degrees within the next 24-36 hours, the lower the humidity and the warmer, the Occurs faster, moreover, even earlier, under such conditions, loss of activity occurs.)
At the present time, scabies are increasingly being considered along with those diseases whose transmission occurs sexually, for example, along with the same fthiracy (this is nothing more than pubic lice). An important feature of scabies is not so much the act of coition (coitus), as the contact of bodies in bed leading to infection.
It is important to take into account the fact that scabies in animals (dogs, cats, etc.) can also be on the skin of a person on contact. Meanwhile, in this version there are no conditions that would be suitable for their subsequent existence, because their rather rapid death occurs. Concomitant of their ingestion on the skin manifestations may be rash and itching, which very soon pass even without treatment, provided, of course, that the condition for their further prevention is met.
So, let’s dwell on what exactly are the signs of scabies and its other features.
The duration of the course of the incubation period (the time interval between the parasite entering the skin and the manifestation of symptoms accompanying scabies) is from 7 to 14 days. A characteristic, although not always mandatory symptom of the disease, is itching. It is amplified, as is clear from the features already considered, in the evening and at night.
In addition, the skin begins to appear nodular-bubble paired rashes, centered in the area most loved by parasites. Scabrous strokes have the appearance of slightly pronounced strips, somewhat elevated above the level of the skin, these strips can be compared with a zigzag or rectilinear thread on the skin. In many cases, the completion of such a course is marked by the formation of a transparent bubble, through which one can consider the point of white color — actually the body of the parasite. In some variants of the course of the disease, scabies are not detected — accordingly, so it appears scabies without strokes.
In those places where the bite was produced, small nodules (similar to a millet seed and a little bit more) appear, these knots begin to become covered with bloody crusts when combed. With the primary rash, small erythematous papules (bulge, bundle) are formed, they, in turn, can be concentrated or scattered or, conversely, merging and multiple. Gradually, the papules can be transformed into a bubble or, more rarely, a bullous rash. The degree of manifestation of the rash is not related to the total number of parasites. It is caused, first of all, by the allergic reaction, arising in address to the actual products of vital activity of parasites.
Due to the fact that the skin is constantly affected by itching, the course of the disease in many cases is complicated due to the adhesion of the pustular infection, and also because of the development of the eczematous process.
As for the areas of their localization that are already noted in the parasite’s favorites, it is primarily the hands (especially the lateral finger surfaces and folds between the fingers), folds on the folds of the shoulder and forearms, the area of the nipples (in particular, this is true for scabies in Women), skin in the penis (respectively in men), as well as the region of the popliteal and hips, stomach (navel area). Scabies in young children in particular manifests itself in such a favorite place for parasites, as soles, face, and in some cases the scalp is also affected.
In facilitating the diagnosis, such characteristic manifestations of the disease as Ardi’s symptom (appearance of pustules in combination with purulent crusts in the region of elbows, as well as in their circumference), Michaelis symptom (The appearance of bloody crusts with rashes in the area of the interannual fold when they cross over to the sacrum), Gorchakov’s symptom (the appearance of bloody crusts in the region of the elbows, as well as in their circumference) and Cesari’s symptom (revealing moves with a characteristic elevation when feeling).
Thus, itching, rash and visible itch moves — it is these signs of scabies that are considered as the main components of its symptomatic manifestation.
Scabies of cleanliness: symptoms
There is a so-called scabies of cleanliness , the symptoms of which are manifested with a minimum degree of severity and intensity. So, rashes with it appears much less than in the usual version of the disease, they are not too noticeable, and the itch, traditionally arising at night, here worries patients less. Also this form can be defined as scabies incognito.
Nodular scabies: Symptoms
Symptoms of scabies in humans with the following form, and this nodular scabies, are manifested as a result of a specific immune response. Its main clinical manifestation is the formation of red-brown nodules under the passages. The areas of rash of such nodules are quite typical for scabies. This form itself is characterized by its own resistance (resistance) to specific therapy, because dense crusts suppress the medication that is applied within its framework.
Cervical scabies: symptoms
Next, cortical scabies (or Norwegian scabies). It is rarely diagnosed, the main group of patients at the same time has weakened immune reactivity. It should also be noted that it is this form that determines the greatest degree of infectivity due to the increased concentration of ticks in the formed crusts. With actual general diseases (in combination with a low immunity), with immunodeficiency states, and also with long-term therapy with cytostatics and corticosteroids, and with alcoholism, the chances of developing cortical scabies significantly increase.
As for the clinical manifestations of this form of the disease, they consist in the appearance on the skin of a dirty-gray color of crusts predisposed to subsequent layering between themselves. As a rule, these crusts have different thicknesses and sizes, they are characterized by close adhesion, both to each other, and to the tissues below them. Removal of such crusts determines the increased soreness, after this manipulation, yellow erosive formations remain on the skin.
The lesions in this case are subject to the aforementioned areas, less often in the picture of the disease there is a lesion of the scalp and face. Due to the development of dense hyperkeratosis on the soles and on the palms (excessive form of thickening that forms within the stratum corneum of the skin), severe stiffness of the movements is noted in the patients. When lesioned against the background of the disease of the nail plates, their deformation and crumbling are noted, the color changes and a characteristic thickening at the base of the plates arises. Inadequate therapy for this form of scabies can cause the development of dermatitis of one kind or another, microbial eczema, pyoderma and other complications.
In this case, the cases already considered in the general description of scabies, under which infection occurred through animals, are subject to consideration. Symptoms of this form of scabies are characterized by a short incubation period, scabies are not formed (due to the inappropriateness of mites to conditions that are relevant for being on the host, not corresponding to the conditions of their typical stay). In the area of open areas of the skin, urticaria papular lesions are formed. Further transmission of the disease to the person in this case is impossible.
The patient’s complaints and actual clinical data are considered as the basis for the diagnosis. Itching at night, characteristic combing, the appearance of small papules in combination with Ardi’s symptom — all this determines the likelihood of the patient having scabies. In addition, the patient’s recent stay in the epidemic focus of the disease can be taken into account.
As for specific laboratory studies, which are used to diagnose scabies, there are several.
So, this is the parasite extraction method when using a needle in the area of the final section of the itch (low efficiency in this study for dilapidated papular elements). Also this is the method of performing thin sections of the stratum corneum in the area in which the itch is located for subsequent microscopy, revealing both the tick itself and eggs laid by it.
Using a procedure such as a method of layer-by-layer scraping, , the final site of the itch is examined until the blood begins to be allocated. The material seized in this case is subject to subsequent microscopy. And finally, the method of alkaline preparation, at which, accordingly, an alkaline solution is applied to the skin, aspiration is carried out followed by microscopy.
A reliable confirmation of the diagnosis is, in addition to the results and symptoms, the presence of itch moves. The assumed itch is opened with a scalpel using an oily substance, after which a careful scratching of the area of the skin along the course is performed, after which scraping, while removed on the glass, is studied under a microscope.
Treatment of scabies
It should be noted immediately that this disease itself does not pass. Moreover, chronic scabies are the variant of its course, in which it can manifest itself for many months and years with periodic self-aggravation. To heal, it is required to destroy both the mite itself and the eggs laid by it, for which the methods of local therapy (application of preparations to the skin) are applied. General treatment in scabies does not apply.
The main drugs used in the treatment of this disease:
- synthetic derivatives of the form of balsamic preparations (eg benzyl benzoate)
- preparations on sulfuric basis, and also on the basis of its derivatives (sulfuric ointments (10-33%), etc.);
- antiparasitic insecticides (creolin, flicid, lysol, ointment of pyrethra, etc.)
- treatment of scabies with folk remedies (fuel oil, kerosene, gasoline, etc.)
- various aerosol preparations, etc.
The chosen method of treatment is that the patient washes, and then applies the drug on the skin, excluding the scalp. Specific measures depend on the particular drug used in the treatment.
Treatment of cortical scabies is somewhat more specific. To begin with, it is necessary to soften the formed crusts, after which to remove them (due to this, the arisen «block» will be eliminated to affect the parasites, which are such crusts). To this end, baths are usually used on a soap-soda basis, as well as keratolytic ointments. Further, after the removal of the crusts, the disease is treated according to the standard scheme prescribed by the doctor.
If you have symptoms of scabies, you should visit a treating therapist, dermatologist or infectious disease specialist.