Scabies: Clinical Guidelines

List of Abbreviations

ICD – International Statistical Classification of Diseases and Related Health Problems

SanPiN – Sanitary Rules and Norms

SRLD – State Register of Medicinal Products

Terms and Definitions

Scabies is a common parasitic skin disease caused by the itch mite Sarcoptes scabiei.

Pseudosarcoptic mange is a disease in humans caused by animal itch mites.

Scabicides are medications used to destroy ectoparasites, including the itch mite (P03A according to the ATC classification).

1. Brief information on the disease or condition

1.1 Definition of the disease or condition

Scabies is a common parasitic skin disease caused by the itch mite Sarcoptes scabiei.

1.2 Etiology and pathogenesis of the disease or condition (group of diseases or conditions)

The causative agent is the itch mite Sarcoptes scabiei. In terms of their type of parasitism, itch mites are permanent parasites, spending most of their life in the host's skin and adopting an ectoparasitic lifestyle on the skin surface only during a short dissemination period. The circadian rhythm of activity of the itch mite explains the intensification of itching in the evening, the predominance of direct transmission via contact in bed during the evening and nighttime, and the effectiveness of prescribing medications to destroy ectoparasites, including the itch mite, at bedtime. The adult female survives for up to 3 days at room temperature, while losing pathogenic properties earlier. The female rapidly penetrates the thickness of the epidermis, forming so-called "burrows", where she lays eggs from which larvae hatch. The larvae leave the burrows through openings in their roofs and penetrate hair follicles, as well as make lateral (metamorphic) burrows branching from the maternal ones. Follicular papules form at the site of the former, and non-inflammatory vesicles at the site of the latter. The invasive stages are the females and larvae of the mite.

1.3 Epidemiology of the Disease or Condition

The intensive incidence rate of scabies in the Russian Federation per 100,000 population decreased 5.8-fold over 13 years: from 64.7 (2010) to 11.2 (2022) [1]. An epidemiologically significant population group in scabies is children, among whom the incidence is significantly higher than in adults [2].

A scabies focus is defined as a group of people that includes an infected individual serving as the source of transmission, along with conditions for pathogen transmission. A focus with a single patient is potential; with two or more, it is irradiating. The family is the most epidemiologically significant focus of scabies. In the irradiation of a focus, contact with the patient in bed at night during the period of maximum pathogen activity plays a decisive role (direct pathway of infection transmission). The invasive stages are females and larvae.

The second place in epidemic significance is occupied by invasion-contact collectives—groups of people living together who share a common bedroom (dormitories, orphanages, boarding schools, nursing homes, barracks, "supervised" wards in psychoneurological hospitals, etc.) with close domestic contact with each other in the evening and at night. Scabies transmission occurs predominantly through close bodily contact in bed in the evening and at night and via intimate relations (direct pathway of invasion). The indirect pathway of transmission (via household items, clothing, etc.) is recorded less frequently. It is observed primarily in foci where there are patients with generalized scabies, a long history of the disease, Norwegian scabies, or scabies erythroderma.

1.4 Features of Coding the Disease or Condition

B86 Scabies

1.5 Classification of the disease or condition

There is no universally accepted classification. Typical and rare clinical variants of the disease course are distinguished.

1.6 Clinical presentation of the disease or condition

The incubation period upon infection by female itch mites is practically nonexistent, as upon reaching human skin, the female immediately penetrates it and begins burrowing. In the case of larval invasion, one can speak of an incubation period corresponding to the time required for the larva to metamorphose into an adult female (about 2 weeks).

Pruritus is a characteristic subjective symptom of scabies, caused by sensitization of the body to the pathogen and its metabolic products. In primary invasion, itching appears a few days later, whereas in reinfection, it appears within 24 hours. The intensification of itching in the evening and at night is associated with the circadian activity rhythm of the pathogen.

Rash in scabies is caused by the activity of the mite (burrows, follicular papules, non-inflammatory vesicles), an allergic reaction of the body to its metabolic products (miliary papules, excoriations, hemorrhagic crusts), and pyogenic microflora (pustules).

Clinical varieties of scabies:

- typical,

- burrowless scabies,

- scabies of the "cleanly" or "incognito" type,

- scabies lymphoplasia of the skin,

- scabies erythroderma,

- Norwegian scabies,

- complicated scabies (with pyoderma, allergic dermatitis, and less commonly microbial eczema and urticaria), pseudosarcoptic mange.

Typical scabies is characterized by the presence of various types of burrows, follicular papules on the trunk and limbs, non-inflammatory vesicles near the burrows, numerous linear excoriations, and hemorrhagic crusts.

Burrows are the main clinical symptom of scabies. By chewing a tunnel in the Malpighian layer of the epidermis, the female lays eggs from which larvae hatch.

Three groups of burrows are distinguished, comprising up to 15 clinical variants:

1. The initial (intact) type of burrow and variants of burrows whose formation is associated with the skin's ability to react with the appearance of certain primary morphological elements (papules, vesicles, bullae) at the site of the female mite's penetration and its vital activity during burrowing. These burrows are called reactive (initial type with vesicle, chain of vesicles, burrow in the roof of a bulla, scabies lymphoplasia of the skin).

   Burrows formed from the clinical variants of the first group's burrows during the natural regression of the burrows themselves and/or the transformation of the primary morphological elements associated with them into secondary ones—fissures, punctate or linear serous crusts, etc.

2. Burrows caused by the addition of a secondary infection to the exudate of cavity elements of the first group's burrows, resulting in the appearance of pustules in their place.

3. Typical burrows appear as a slightly raised whitish or dirty-gray line, straight or curved, 5–7 mm long. Scabies burrows are localized in almost all patients on the hands, less frequently on the flexor surface of the wrists, feet, elbows, and male genitalia. Localization of burrows on the feet predominates in patients with a disease duration of 2 months or more, and in individuals in contact with petroleum products and disinfectants. "Paired elements" should not be considered a diagnostic symptom of the disease.

So-called "paired elements" should not be equated with burrows or considered a diagnostic sign of the disease.

Papules, vesicles, excoriations, and hemorrhagic crusts predominate in the clinical picture of the disease. Papules containing mites are characterized by severe itching, follicular arrangement, and small size (up to 2 mm), while vesicles are characterized by small size (up to 3 mm), absence of inflammation ("pearly" vesicles), and location near scabies burrows. Mites are present in 1/3 of papules and vesicles, while the rest are the result of an allergic reaction.

Burrowless scabies is recorded less frequently than typical scabies, is detected primarily during the examination of individuals who have been in contact with scabies patients, occurs upon infection with larvae, exists in its initial form for no more than 2 weeks, and is clinically characterized by solitary follicular papules and non-inflammatory vesicles.

Scabies of the "cleanly" or "incognito" type occurs in individuals who frequently take water procedures, especially in the evening, and corresponds in its clinical picture to typical scabies with minimal manifestations.

Scabies lymphoplasia of the skin is clinically manifested by intensely pruritic lenticular papules, localized on the trunk (buttocks, abdomen, axillary region), male genitalia, female breasts, and elbows. It persists after successful scabies therapy for from 2 weeks to 6 months. Epidermal scraping from its surface accelerates resolution. Upon reinfection, it recurs in the same places.

Scabies erythroderma occurs in cases of prolonged use of erroneously prescribed corticosteroids, systemic antihistamines, psycholeptics, and psychoanaleptics [3]. Pruritus is moderate and diffuse. Patients usually rub the skin with their palms rather than scratching it, and excoriations are typically absent.

The main symptom is pronounced erythroderma. Hyperkeratotic layers are absent. Skin xerosis is pronounced with minimal scaling. Numerous scabies burrows are visualized in typical localization sites (hands, wrists, feet). Short burrows (2–3 mm) can also be detected on areas of the skin atypical for scabies (face, neck, scalp, interscapular region). In areas subject to pressure (elbows and buttocks), hyperkeratosis is pronounced. The disease is highly contagious.

Norwegian (crusted) scabies is currently not a rare dermatosis. In the Russian Federation, more than a third of dermatologists have encountered it in clinical practice [4]. The pathogenetically significant mechanism for the development of this form of scabies is the elimination of pruritus as a protective bodily reaction aimed at the mechanical removal of mites from the skin during scratching, which maintains the pathogen population size at a certain level. It is observed against the background of immunodeficiencies and immunosuppressive states of various origins, with prolonged use of hormonal and cytostatic drugs, impaired peripheral sensitivity, constitutional keratinization anomalies, and in patients with mental illnesses who are taking antipsychotics and psychotropic agents [5, 6]. Norwegian scabies is severe in HIV-infected patients [7, 8] and drug addicts [9]. In recent years, the cause of Norwegian scabies has been the comorbidity of somatic pathologies of various origins, among which cardiovascular diseases are in the lead [10-12]. Elderly and senile individuals are at risk. The main symptoms of the disease are massive dirty-yellow, gray, or brownish-black crusts ranging from a few millimeters to 2–3 cm in thickness, up to large hyperkeratotic crustous layers. The number of mites in them reaches up to 200 individuals per cm², and the burrows are arranged in multiple tiers. The crusts restrict movement, causing painful sensations. A multitude of scabies burrows are visualized on the hands and feet. The development of erythroderma is possible. The nail plates of the hands and feet are frequently affected, hair falls out, body temperature rises, and regional lymph nodes enlarge. A foul odor emanates from the patients. The disease is highly contagious. Micro-epidemics frequently occur among the contacts of patients—all family members, medical workers, and patients in the same ward become infected.

Complicated scabies. Scabies is often complicated by secondary pyoderma and dermatitis, less commonly by microbial eczema and urticaria. Among the nosological forms of pyoderma, staphylococcal impetigo, ostiofolliculitis, and deep folliculitis predominate; furuncles and vulgar ecthyma occur less frequently. Impetigo predominates in the localization sites of scabies burrows (hands, wrists, feet), and ostiofolliculitis in the areas of mite metamorphosis (anterolateral surface of the trunk, thighs, buttocks). Microbial eczema is more often observed at the localization sites of scabious cutaneous lymphoplasia, especially in the gluteal region and on the elbows.

Scabies in children is characterized by a greater dissemination of the process involving the skin of the face, scalp, and nail plates (in infants). Reactive variants of scabies burrows running within the roof of exudative morphological elements (bullae, vesicles) predominate, scabious cutaneous lymphoplasia is common, and complications (pyoderma, allergic dermatitis, microbial eczema) are frequent [13-15]. In children, especially infants, the nail plates may be affected [6]. Scabies in infants, unlike in adults, manifests as edematous seropapules and vesicles, thus resembling the clinical picture of strophulus. Their rashes and scabies burrows are frequently localized on the palms and soles, especially in the area of the dorsum of the foot and on its inner arch. In daily bathed children, scabies burrows are barely noticeable; most often they can be seen only on the soles, where the stratum corneum is more developed and the destruction of burrows is delayed. The most frequent complication of scabies is bacterial superinfection caused by both S. aureus and S. pyogenes. If antibacterial therapy is not initiated in a timely manner, the patient may develop post-streptococcal glomerulonephritis [48].

Scabies in elderly individuals has certain features: scabies burrows are single due to the involution of sweat glands, and intact variants predominate; vesicles and papules are few in number, with many bloody crusts and excoriations. With a long disease duration and violation of treatment regimens (treatment with ectoparasite-destroying agents, including the scabies mite, of not the entire skin surface), mites migrate to the face, scalp, and retroauricular areas, where they form scabies burrows. The disease persists. The comorbidity of somatic pathology of various origins is a prerequisite for the development of Norwegian scabies, scabious erythroderma, scabies with multiple rashes of scabious cutaneous lymphoplasia in various areas of the skin, and recurrent pyoderma.

Diagnostic symptoms in scabies:

1. Hardy's sign – pustules and purulent crusts on and around the elbows;

2. Gorchakov's sign – bloody crusts in the elbow area and its surroundings;

3. Michaelis' sign – bloody crusts and impetiginous rashes in the intergluteal cleft extending onto the sacrum;

4. Cesarie's sign – palpation of a scabies burrow as a slight band-like elevation.

2. Diagnostics, medical indications and contraindications for diagnostic methods

Criteria for establishing the disease diagnosis

The diagnosis of scabies is established based on a set of clinical and epidemiological data, confirmed by laboratory studies aimed at detecting the pathogen, as well as after a positive effect from trial therapy with an ectoparasite-destroying agent, including the scabies mite (ex juvantibus).

2.1 Complaints and Anamnesis

Patients are bothered by itching that intensifies in the evening and at night—a characteristic subjective symptom of scabies, rashes on the hands, wrists, anterior body surface, buttocks, and genitalia in men. The presence of the disease in contact persons.

2.2 Physical Examination

Objective clinical manifestations of scabies detected during physical examination are described in the "Clinical Presentation" section.

Comments: due to the bloodless state of the capillary bed upon pressing with a glass slide, the visualization of superficial skin inclusions is improved.

2.3 Laboratory Diagnostics

Comments. The result is considered positive if the specialist conducting the study finds a female mite, larva, eggs, and empty eggshells in the specimen. Pathogen feces are not a reliable diagnostic criterion. Their presence indicates the need to repeat the study. In an outpatient setting with a high patient flow, maximum laboratory diagnostic efficiency is ensured if the physician marks several sites for material collection, and the laboratory technician scrapes the epidermis in this area and examines the prepared specimen under a microscope.

2.4 Instrumental Diagnostics

Comments: the scabies burrow looks like a whitish line, and at the site of exit of the female mite, a small dark-brown delta-shaped structure can be identified, which is the body of the adult female mite. A scabies burrow filled with eggs looks like a "string of pearls". Dermatoscopy is an effective method for examining a patient with scabies [16, 17]. Its use makes it possible to detect the pathogen directly in the skin. The diagnostic significance of dermatoscopy increases in the presence of scabies burrows associated with exudative morphological elements (vesicles, bullae, pustules). In patients with scabious erythroderma and Norwegian scabies, mites are detected by dermatoscopy even in outwardly unchanged skin [19-20]. Dermatoscopy can be used to detect mites and their eggs. A positive result is recorded in 100% of cases for typical scabies, and in 32% for burrowless scabies. Photo and video recording of mites during dermatoscopy makes it possible to preserve the digital image and resolve controversial issues with the patient.

2.5 Other Procedures

Comments: the detection of mites on adhesive tape indicates the possibility of indirect transmission in scabies foci.

Comments: due to the blanching of the capillary bed when pressed with a glass slide, the visualization of superficial skin inclusions is improved. The clearing effect is enhanced after the preliminary application of mineral oil to the suspected scabies burrow.

3. Treatment, including drug and non-drug therapies, diet therapy, and pain management

3.1 Conservative Treatment

3.1.1 Treatment of uncomplicated scabies

Comment: for children aged 3 to 5 years, a 10% emulsion (by diluting the 20% one) and ointment are used (according to the instructions for benzyl benzoate**), and for individuals over 5 years old, a 20% emulsion and benzyl benzoate** ointment are used. Before starting treatment (in the absence of complications), the patient is advised to wash with soap. The emulsion is shaken before use. The preparations are applied to the skin in the evening twice – on the 1st and 4th days of treatment. Hands should not be washed for 3 hours after treatment. If there is a need to wash hands, they should be treated again. It is advisable to rub the drug in the following sequence: hands – torso – legs. When applied to the skin, a burning sensation often occurs, which disappears after a few minutes; the patient must be warned about this. After a 12-hour exposure on the skin, the product can be washed off. Contact of benzyl benzoate** with mucous membranes should be avoided. Treatment of scabies complications (pyoderma, allergic dermatitis, etc.) is carried out on the 2nd, 3rd, and subsequent days of the course. On the 5th day, the patient is advised to wash and change underwear and bed linen.

Considering that benzyl benzoate** emulsion is available in a 20% concentration for the treatment of children aged 3 to 5 years, this product should be diluted with warm water in a 1:1 ratio before rubbing into the skin. Benzyl benzoate** is not used in pregnant women and children under 3 years of age due to existing contraindications [8-14].

Comments. In Russia, a 5% permethrin concentrate in ethanol is available for the preparation of a 0.6% emulsion for external use [14, 16, 23, 33].

A 0.6% aqueous emulsion is prepared ex tempore by diluting 12 ml of 5% permethrin concentrate in ethanol with room temperature water (100 ml). The drug is rubbed in 1 time per day at night on the 1st and 4th days of the course. It is used in children starting from one year of age. It is used with caution during lactation [41, 42] and in pregnant women [42, 43].

sulfur, concentration 33.3% (sulphur praecipitatum) [9, 10, 13, 14, 31, 24, 25, 27, 29, 3, 44].

GCP CLEL 5Grade of Recommendation – C (Level of Evidence – 5)

Comments: it is not recommended for use during pregnancy and in children under 2 years of age. Sulfur ointment is applied to the skin after washing with soap 1 time per day at night for several days. The duration of the course depends on the prevalence of the process. The drug is rubbed into the skin of the hands, then the torso and legs, including the soles and toes. In the morning, the ointment can be washed off. The use of a 33% concentration often leads to the development of allergic dermatitis. It is not recommended for use during pregnancy and in children under 2 years of age. For children, it is recommended to prepare sulfur ointment ex tempore from 5 to 20%; for the treatment of infants, a 5% sulfur oil suspension ex tempore is used [48].

3.1.2 Treatment of scabies in pregnant women

or #benzyl benzoate** 20% ointment [51, 59].

GCP CLEL 5Grade of Recommendation – C (Level of Evidence – 5)

Comments: use with caution.

3.1.3 Treatment of scabies in children aged 1 to 3 years

Comments.  The product is applied once in the evening and rubbed into the skin. After 8–12 hours, the product must be thoroughly washed off. The emulsion is rubbed in on the 1st and 4th days of treatment. Re-treatment is possible no earlier than 8 days later [50, 54].

Rubbing in the medicinal product for the destruction of ectoparasites, including the itch mite, is carried out over the entire skin surface, including the face, neck, and scalp.  It is advisable to use a cotton swab to treat accessible areas of skin under the nail plates. For children aged 3 years and older, a 5% sulfur-based ointment can be used  (prepared ex tempore) [6, 27, 39, 48]. The issue of treating children of this age with 5% sulfur ointment can be resolved in a medical institution by a special commission. The parents or legal guardians of the child must receive detailed instructions on the use of the product from the physician and give informed consent for treatment, both in an inpatient setting and at home.

3.1.4 Treatment of scabies in infants under 1 year

Currently, there are no officially registered drugs in Russia for the treatment of this age group of children [26, 27, 30, 45, 46].

Comments: in clinical practice, a 10% #benzyl benzoate** emulsion is used topically from 6 months of age; the drug is diluted with boiled water in a 1:1 ratio [48, 49, 58, 61].

3.1.5 Treatment of scabies complicated by pyoderma

Comments: preference is given to medications for eliminating ectoparasites, including the scabies mite, the application of which does not require intensive rubbing and does not contribute to the spread of infection across the skin. On the evening of the 1st day, pustules are cauterized with antiseptics and aniline dye preparations (solutions of aniline dyes, 5% potassium permanganate, povidone-iodine). After the antiseptics and disinfectants have dried, treatment is performed with a 0.6% aqueous emulsion of permethrin, or a 10% or 20% emulsion of benzyl benzoate** (taking into account the patient's age). This eliminates itching as the cause of skin integrity disruption. The second application of the medication for eliminating ectoparasites, including the scabies mite, is carefully rubbed in on the 4th day of the course. Pyoderma treatment is carried out on the 2nd, 3rd, and subsequent days. The question of washing the patient before applying the medication for eliminating ectoparasites, including the scabies mite, is decided by the physician on an individual basis, taking into account the possibility of infection dissemination [4, 6, 18, 47].

The medicinal product for the destruction of ectoparasites, including the itch mite, is rubbed in on the 1st and 4th days of the course, while pyoderma is treated on the 2nd and 3rd days.  

Treatment of allergic dermatitis is carried out on the 2nd, 3rd, and subsequent days. Treatment of allergic dermatitis is carried out in accordance with the clinical guidelines for this dermatosis.

Treatment of scabies complicated by microbial eczema begins with the treatment of microbial eczema in accordance with the clinical guidelines for "Eczema". After the resolution of infiltration and the shedding of crusts in its place, lenticular papules, often multiple (scabies lymphoplasia), are frequently well visualized.

3.1.7 Treatment of scabies with scabtic lymphoplasia of the skin

Comments. If scabies lymphoplasia persists after the resolution of the main clinical manifestations of scabies, dermatological corticosteroids can be used under an occlusive dressing or medicinal ultraphonophoresis with these drugs can be used, except for cases where the process is localized on the genitals. Skin cryodestruction can be used.

3.1.8 Treatment of Norwegian (crusted) scabies

• When treating Norwegian scabies: it is recommended to treat the patient in the evening with an ectoparasiticide containing an anti-scabies agent (scabicide) to kill active forms of the pathogen and reduce the patient's contagiousness. Prior to this, a keratolytic agent (5% and 10% salicylic acid ointment) should be applied [4, 6, 18, 21, 53, 54, 56, 57, 58, 61].

LoE CGoR 5Level of evidence – C (grade of recommendation – 5)

Comments: treatment should be continued until the complete resolution of crusts. Subsequently, for 2–3 days, the patient is treated in the evening with a scabicide only. For better drug penetration, it is advisable for adults to use liquid dosage forms of ectoparasiticides, including scabies mites (scabicids) (benzyl benzoate** emulsion and 0.6% permethrin emulsion) for adults and children over 3 years of age, applying them to the skin using household manual sprayers. An important condition is regular examination of epidermal scrapings to detect the itch mite. If motile forms are detected, it is recommended to repeat the course of specific therapy while switching to a different ectoparasiticide, including scabies mites (scabicide).

If treatment is ineffective, reinfection must be ruled out.

3.1.9 Treatment of scabtic erythroderma

Treatment is carried out in the same way as for Norwegian scabies, but without the use of keratolytic agents.

3.2 Surgical Treatment

Not applicable.

3.3 Other Treatment

Diet therapy is not indicated.

Pain management is not performed.

4. Medical Rehabilitation and Sanatorium-Resort Treatment

Not applicable.

5. Prevention and Dispensary Observation

Comments:

1. Every newly diagnosed case of scabies is subject to registration and recording in the established manner by medical organizations, as well as by territorial bodies authorized to exercise federal state sanitary and epidemiological supervision.

2. Identification and examination of the source of infection and contacts. Determination of the group of contacts subject to preventive treatment. Serious attention is paid to sexual partners, both within and outside the family.

3. Identification of scabies foci and work on their elimination. Members of organized groups are examined by medical personnel on-site.

4. Preventive treatment is indicated for persons who have been in close household and sexual contact with a scabies patient, family members, and members of infection-prone groups living with the patient in the same premises. A single treatment of the entire skin surface is carried out using one of the anti-scabies drugs. Treatment of patients and preventive treatment of contacts are carried out simultaneously.

5. The follow-up period for a scabies focus with adequate treatment of patients and preventive treatment of contacts in family foci and organized groups is two weeks. Examination of focus members in this case is carried out twice: upon identification of the patient and two weeks later. In organized groups where preventive treatment of contacts was not performed, the examination is carried out three times at 10-day intervals.

6. Dispense observation (follow-up) of scabies patients is carried out by a dermatologist. In cases of scabies without burrows, typical scabies, or "incognito" scabies, after a full course of therapy and a complete set of preventive measures in the focus, the patient is examined twice: after completion of the therapy course and 2 weeks later. The duration of follow-up is extended in cases of scabies complicated by pyoderma, dermatitis, microbial eczema, scabpetic lymphoplasia of the skin, scabpetic erythroderma, and Norwegian scabies. The patient is deregistered 2 weeks after the complete resolution of all clinical manifestations of the disease.

7. Preschool and school-age children with scabies are suspended from attending organized groups for the duration of treatment. Admission to educational institutions is permitted only after completion of the set of treatment and prevention measures, accompanied by a confirming medical certificate.

8. Persistent scabpetic lymphoplasia of the skin is not a contraindication for children to attend organized groups, since after quality therapy the patient loses contagiousness to others. Lenticular papules represent an immunoallergic skin reaction, and the pathogen is absent in them.

9. Deregistration of the patient from clinical follow-up is carried out after the resolution of all clinical manifestations of the disease. The prognosis for scabies is favorable.

10. Current disinfection in the focus is carried out by the patient or a family member caring for them. The attending physician instructs them on the methodology of current disinfection aimed at destroying the pathogen on bed linen, clothing, and personal hygiene items of the patient. Every patient must have a separate bed, bedding, and items for individual use (towel, washcloth, slippers, bathrobe).

11. Disinfection of bedding, underwear, and towels is carried out by washing at a temperature of 70-90^oC, or by soaking for an hour in chlorine-containing solutions. Outerwear is disinfected by ironing the items on both sides with a hot iron, paying special attention to pockets. For the disinsection of textiles, shoes, and children's toys, products intended for these purposes based on permethrin and malathion are used. Some items that cannot undergo thermal processing can be hung outdoors for 3 days. For the disinfection of certain items (children's toys, shoes, clothing), a method of temporary withdrawal from use can be applied by placing them in hermetically sealed plastic bags for 3 days.

12. Terminal disinfection is mandatory in hospitals after the discharge of a scabies patient. For this, items are treated in a disinfection chamber, and premises and furnishings are treated with disinsection agents that have state registration and comply with current sanitary regulations.

13. Disinsection of premises is mandatory during mass outbreaks of scabies in organized groups, in family foci with multiple patients, as well as patients with Norwegian scabies and scabpetic erythroderma, and in the admission ward of a hospital if a scabies patient is identified upon hospitalization.

14. Active case-finding through preventive medical examinations of various population groups (target cohorts, children's groups, draft-age and registered individuals, schoolchildren at the beginning of the academic year, applicants, military personnel, etc.).

15. Mandatory examination for scabies of patients visiting polyclinics, outpatient clinics, medical stations, and upon hospitalization in medical and preventive institutions of any profile.

16. In an unfavorable epidemiological situation in the region, to prevent the introduction and spread of scabies in large organized groups (army, navy, prisons), preventive treatment with ectoparasiticides, including scabies mites (scabicides), is subject to all newly arriving individuals in the quarantine zone. For this purpose, liquid formulations (5% permethrin concentrate in ethanol) are suitable for adults and children from 1 year of age.

17. Active case-finding.

18. Identification and examination of sources of infection, contacts, and determination of the cohort of contacts subject to preventive treatment.

19. Examination of members of organized groups is carried out by medical personnel on-site.

20. Scabies patients are provided with follow-up care by a dermatologist.

21. It is recommended to conduct preventive treatment for persons in close household and sexual contact, family members, and members of infection-prone groups living with the patient in the same premises, by a single skin treatment with one of the other ectoparasiticides, including scabies mites. Treatment of patients and preventive treatment of contacts in the focus are carried out simultaneously.

22. With adequate treatment of patients and preventive treatment of contacts in family foci and organized groups, the observation period is two weeks, with examinations conducted twice—upon identification of the patient and two weeks later. In organized groups where preventive treatment of contacts was not performed, examinations are carried out three times at 10-day intervals.

23. If scabies is detected in preschool and school-age children, they are suspended from attending preschool and general education institutions for the duration of treatment. They may be admitted to educational institutions only after completing a set of treatment and prevention measures, supported by a confirming medical certificate.

24. Cure control is performed on the 3rd and 10th days after the end of treatment.

25. In cases of scabies without burrows, typical scabies, or "incognito" scabies after a full course of therapy and a complete set of preventive measures in the focus, the follow-up period for patients is 2 weeks.

26. The duration of clinical follow-up is extended in scabies complicated by pyoderma, dermatitis, microbial eczema, scabietic lymphoplasia of the skin, scabietic erythroderma, and Norwegian scabies.

27. The attending physician instructs the scabies patient or caregiver on the procedure for carrying out concurrent disinfection aimed at destroying the pathogen on the patient's bedding, clothing, and personal hygiene items. Concurrent disinfection is carried out by the patient themselves or a family member caring for them. Concurrent disinfection is carried out in the presence of the patient from the moment the disease is detected until their recovery or hospitalization.

28. Upon completion of outpatient treatment (or hospitalization), terminal disinfection is carried out: items are processed in a disinfection chamber, and premises and furnishings are treated with state-registered disinfestation agents in accordance with current sanitary regulations (SanPiN).

29. The patient is discharged from the register after the complete resolution of all clinical manifestations. The prognosis for scabies is favorable.

6. Organization of Medical Care

When diagnosing scabies in a patient admitted to a somatic ward of a multidisciplinary hospital, their transfer to a specialized dermatological department (inpatient facility) is not required. The patient ceases to be contagious after the first treatment with a preparation for the destruction of ectoparasites, including the scabies mite (scabicide). In cases of widespread disease, Norwegian scabies, and scabietic erythroderma, temporary isolation of the patient in a single room is necessary for the duration of scabies treatment, where meals are also provided. Daily thorough cleaning of the room using disinfectants is carried out. After the patient is discharged from the hospital, terminal chamber disinfection of bedding (mattresses, pillows, bed linen, and undergarments), as well as their personal clothing, is carried out. Patients sharing a room with a scabies patient before the diagnosis of scabies is established are examined by a physician, and the degree of invasive contact is determined. The issue of preventive treatment for contact patients is decided individually. In Norwegian scabies and scabietic erythroderma, to exclude the possibility of micro-outbreaks, preventive treatment must be administered to medical personnel, caregivers, and roomates [5].

Upon hospitalization in somatic wards of scabies patients requiring emergency medical care, the application of a preparation for the destruction of ectoparasites, including the scabies mite (scabicide), should be performed in the admission department, which prevents infection of others during the two subsequent days. Further specific treatment is carried out in the ward.

When pruritic dermatosis is detected in a patient admitted to a psychiatric hospital, a consultation with a dermatovenereologist and prophylactic treatment with a preparation for the destruction of ectoparasites, including the scabies mite (scabicide), in the admission department are necessary. In the "supervision wards" of psychiatric hospitals, if a patient with any form of scabies is identified, prophylactic treatment is administered to all patients sharing the same room [45].

Indications for hospitalization:

- patients with mental, neurological, and other disorders (when unable to independently carry out necessary prescriptions);

- patients from organized communities when isolation from healthy individuals is impossible (orphanages, boarding schools, etc.);

- scabies complicated by pyoderma, microbial eczema (especially in children), and accompanied by high fever or lymphadenopathy.

Indications for discharge:

- elimination of pruritus and resolution of the clinical manifestations of the disease.

7. Additional Information

Features of the clinical course of scabies when combined with other dermatoses:

1. in scabies against the background of atopic dermatitis and vulgaris ichthyosis (pronounced skin dryness), isolated scabietic burrows are observed;

2. in hyperhidrosis, dyshidrotic eczema, and the dyshidrotic form of dermatophytosis (increased skin moisture), scabietic burrows on the feet are multiple, whereas in the hypertrophic form (pronounced dryness and thickening of the epidermis), burrows on the hands and feet are single [46];

3. in scabies against the background of psoriasis and lichen planus, as a rule, the isomorphic Köbner reaction is sharply pronounced;

4. pseudosarcoptic mange is a disease occurring in humans upon infestation with animal scabies mites (dogs, pigs, horses, rabbits, wolves, foxes, etc.). The disease is not transmitted from person to person. The incubation period is several hours. Scabietic burrows are absent, as the mites do not reproduce on an unusual host and only partially penetrate the skin, causing severe itching. Rashes are localized on exposed skin areas and present as urticarial papules, wheals, blood-crusted lesions, and excoriations.

General principles of treating scabies patients regardless of the preparation used for the destruction of ectoparasites, including the scabies mite (scabicide).

1. Treatment of patients in the focus must be carried out simultaneously to avoid reinfestation.

2. The application of preparations for the destruction of ectoparasites, including the scabies mite, in children under 3 years of age is carried out over the entire skin surface; in other patients, the face and scalp are excluded.

3. In elderly and senile individuals, especially with a previously registered history of non-compliance with treatment regimens, as well as in patients with Norwegian scabies and scabietic erythroderma, the entire skin surface, including the face, neck, and scalp, is treated with the preparation for the destruction of ectoparasites, including the scabies mite.

4. Treatment is carried out in the evening due to the circadian rhythm of the pathogen's activity.

5. The application of preparations for the destruction of ectoparasites, including the scabies mite, is carried out exclusively with bare hands to ensure better penetration of the drug into burrows, which are predominantly located on the hands and wrists.

6. Treatment of scabies complications is carried out simultaneously with the treatment of the underlying disease.

7. Contact persons in the focus of the disease undergo prophylactic treatment to avoid "ping-pong" infection. In each focus, the selection of persons for this procedure is decided individually, taking into account the degree of invasive contact with the source. Prophylactic treatment consists of a single application of any preparation for the destruction of ectoparasites, including the scabies mite, to the skin. Bathing the patient is recommended before and after the course of treatment. If necessary, preparations for the destruction of ectoparasites, including the scabies mite, can be washed off every morning, while their exposure time on the skin must be at least 8–12 hours, including the nighttime period.

8. Change of underwear and bed linen is carried out after the completion of the therapy course.

9. If post-scabietic pruritus after full therapy with a preparation for the destruction of ectoparasites, including the scabies mite, using systemic antihistamines and dermatological corticosteroids, does not resolve within 7–10 days, a single repeated treatment with a preparation for the destruction of ectoparasites, including the scabies mite, should be performed. The reason for its persistence is young unfertilized females that do not make an opening in the roof of the scabietic burrows for larvae to exit, which limits the drug's access into the burrows [48].

10. Persistent scabietic lymphoplasia of the skin does not require additional specific therapy, as it is the result of an immunoallergic reaction of the body to the mite [49].

Causes of ineffectiveness of preparations for the destruction of ectoparasites, including the scabies mite [6, 50].

1. Insufficient exposure time of the drug on the skin.

2. Survival of the living pathogen under the nails.

3. Pronounced hyperkeratosis on the hands and feet, which hinders drug penetration into the burrows.

4. Skin involvement of the scalp in adults.

5. Single application of the skin covering in generalized disease.

6. Washing hands after treatment without reapplying the drug.

7. Inadequate therapy when scabies is combined with other dermatoses.

8. Reinfestation.

9. Indirect route of reinfection from infested items (clothing, bedding, etc.) with a high parasitic index in the focus.

Post-scabietic pruritus

Post-scabietic pruritus is the persistence of itching after full specific therapy and a set of preventive measures in disease foci (examination of contacts, treatment of identified patients, and prophylactic treatment of individuals who had close contact with the infected patient) [48]. The causes of post-scabietic pruritus are diverse.

- Reaction of the body to mite allergens persisting in the skin for up to 2 weeks (dead mites, their eggs, empty eggshells), which corresponds to the time required for epidermal desquamation along with the pathogen. Treatment includes the administration of systemic antihistamines and topical corticosteroids used in dermatology.

- Persistence in the skin of unfertilized females that do not create openings in the roof of the burrow, which impairs penetration of the ectoparasiticide, including anti-scabies agents, to the pathogen. In this case, pruritus persists for a duration corresponding to the lifespan of the females, depending on their age at the time therapy was initiated, typically up to one month. If pruritus persists despite treatment with systemic antihistamines and dermatological corticosteroids for two weeks, repeated application of an ectoparasiticide, including anti-scabies agents, is indicated following thorough washing with soap and a washcloth.

- Dryness of the skin. In this case, emollients are prescribed.

Criteria for Evaluating the Quality of Medical Care

References

Appendix A1. Working Group Composition

1. Kubanov Alexey Alekseevich – Academician of the RAS, President of the All-Russian public organization "Russian Society of Dermatovenerologists and Cosmetologists" (RODVK), Director of the State Research Center of Dermatovenereology and Cosmetology of the Russian Ministry of Health, Head of the Department of Dermatovenereology and Cosmetology at the Russian Medical Academy of Continuous Professional Education (RMACPE) of the Russian Ministry of Health, Moscow.

2. Zaslavsky Denis Vladimirovich – MD, Professor, Head of the Department of Dermatovenereology at Saint Petersburg State Pediatric Medical University, member of the Russian Society of Dermatovenerologists and Cosmetologists, Saint Petersburg.

3. Sokolova Tyania Veniaminovna – MD, Professor at the Department of Skin and Venereal Diseases of the Medical Institute of Continuing Education of the Russian Biotechnological University, member of the Russian Society of Dermatovenerologists and Cosmetologists, Moscow.

4. Malyarchuk Alexander Petrovich – MD, Associate Professor, Professor at the Department of Skin and Venereal Diseases of the Medical Institute of Continuing Education of the Russian Biotechnological University, member of the Russian Society of Dermatovenerologists and Cosmetologists, Moscow.

5. Gladko Viktor Vladimirovich – MD, Professor, Director of the Medical Institute of Continuing Education, Head of the Department of Skin and Venereal Diseases with a Course of Cosmetology at the Russian Biotechnological University, member of the Russian Society of Dermatovenerologists and Cosmetologists, Moscow.

6. Lopatina Yulia Vladimirovna – Candidate of Biological Sciences, Senior Researcher at the Department of Entomology, Faculty of Biology, Lomonosov Moscow State University, Moscow.

7. Bogdanova Elena Vitalievna – Candidate of Medical Sciences, Senior Researcher at the Scientific and Organizational Department of the State Research Center of Dermatovenereology and Cosmetology of the Russian Ministry of Health, Moscow.

Conflict of interest: the authors declare no conflict of interest.

Appendix A2. Methodology for Developing Clinical Guidelines

Target audience of the clinical guidelines:

1. general practitioners (family physicians), allergists-immunologists, infectious disease specialists, epidemiologists, etc.

2. Residents, postgraduate students, and trainees of continuing professional education programs in the specified specialties.

Table 1. Scale for assessing levels of evidence (LE) for diagnostic methods (diagnostic interventions)

Table 2. Levels of Evidence (LoE) grading scale for prevention, treatment, and medical rehabilitation methods, including those based on natural therapeutic factors (preventive, therapeutic, and rehabilitative interventions)

Table 3. Scale for assessing the grades of recommendation (GR) for prevention, diagnostic, treatment, and medical rehabilitation methods, including those based on natural therapeutic factors (preventive, diagnostic, therapeutic, and rehabilitation interventions)

Procedure for updating clinical guidelines

The clinical guidelines update mechanism provides for their systematic revision at least once every three years, as well as upon the emergence of new evidence-based medicine data regarding the diagnosis, treatment, prevention, and rehabilitation of specific diseases, or in the presence of justified additions/comments to previously approved clinical guidelines, but no more frequently than once every 6 months.

Appendix A3. Reference Materials

1. Order of the Ministry of Health of the Russian Federation No. 924n of November 15, 2012, "On approval of the procedure for providing medical care in the profile 'dermatovenereology'."

2. State Register of Medicines of the Russian Federation.

3. Order of the Ministry of Health of the Russian Federation No. 162 of April 24, 2003, "On approval of the industry standard 'Protocol for the management of patients. Scabies'."

4. Resolution of the Chief State Sanitary Doctor of the Russian Federation No. 4 of January 28, 2021, "On approval of sanitary rules and norms SanPiN 3.3686-21 ('Sanitary and epidemiological requirements for the prevention of infectious diseases')."

5. Methodological Guidelines MU 3.2.1756-03 of March 28, 2003, "Epidemiological surveillance of parasitic diseases."

6. Methodological recommendations for physicians "Scabies" / authors: Kubanova A.A., Sokolova T.V., Lange A.B. M. – 1992. – 20 p.

7. Methodological recommendations for military medical service physicians of the Ministry of Defense of the Russian Federation "Organization of care for military personnel with scabies in military medical institutions of the Ministry of Defense of the Russian Federation" / authors: Gladko V.V., Sokolova T.V., Ryazantsev I.V. – M. – 2004. – 63 p.

8. Russian Federation. Laws. On the circulation of medicines: Federal Law No. 61 [adopted by the State Duma on March 24, 2010; approved by the Federation Council on March 31, 2010]. – Moscow.

9. Order of the Ministry of Health of the Russian Federation No. 80n of February 9, 2016, "On approval of the procedure for maintaining the state register of medicines for medical use."

10. Order of the Ministry of Health of the USSR No. 254 of September 3, 1991, "On the development of disinfection services in the country."

Appendix B. Physician Action Algorithms

**compliance with the rules for applying the medicinal product; processing of underwear.

Appendix C. Patient Information

To increase the effectiveness of scabies treatment, the patient must comply with a number of organizational, sanitary, and hygienic requirements.

- The patient with scabies must inform the physician about data concerning the possible source of infection; name individuals who have been in contact with them; indicate antiparasitic products used previously independently or as prescribed by a physician, etc.

- Clearly understand that the treatment of all patients in the focus and prophylactic treatment of contacts must be carried out simultaneously to avoid reinfection ("ping-pong" infection). For this purpose, the physician must be provided with information not only about family foci, but also about foci in groups where the patient has been (classrooms, dormitory rooms, nursing homes, hospital wards, etc.)

- Treatment must be carried out strictly in accordance with the physician's recommendations for the use of the medicinal product.

- The patient with scabies or their caregiver must carry out current disinfection of personal items, bedding, and premises in the focus. Instructions on the procedure for its implementation are given by the physician.

- Some individuals belonging to the "decreed occupational groups" are suspended from work for the period of treatment. This issue is decided by the physician.

- After completing the course of therapy, the patient must visit the physician for follow-up observation (dispensary monitoring), the duration of which is determined taking into account the clinical form of the disease.

Appendix G. Assessment Scales, Questionnaires, and Other Evaluation Tools

None.