NORWEGIAN SCABIES IN A PATIENT WITH DOWN SYNDROME

Sergei V. Koshkin; Кошкин Сергей Владимирович; Regina N. Zhantlyu; Жантлю Регина Николаевна; Mariya А. Kasatkina; Касаткина Мария Александровна; Yulia Yu. Sykchina; Сыкчина Юлия Юрьевна; Vera V. Ryabova; Рябова Вера Владимировна; Anna L. Evseeva; Евсеева Анна Леонидовна; Nikolay Yu. Ryabov; Рябов Николай Юрьевич

doi:10.25208/vdv16918

NORWEGIAN SCABIES IN A PATIENT WITH DOWN SYNDROME

Authors: Koshkin S.V.¹^,2, Zhantlyu R.N.¹, Kasatkina M.А.¹, Sykchina Y.Y.¹, Ryabova V.V.¹, Evseeva A.L.¹, Ryabov N.Y.³
Affiliations:
1. Kirov State Medical University
2. Kirov Regional Dermatology Hospital
3. Belokholunitskaya Central District Hospital
Section: CLINICAL CASE REPORTS
Submitted: 10.07.2025
Accepted: 28.10.2025
Published: 08.11.2025
URL: https://vestnikdv.ru/jour/article/view/16918
DOI: https://doi.org/10.25208/vdv16918
ID: 16918

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Abstract

This article describes a clinical case of Norwegian scabies in a 36-year-old patient with Down syndrome living in a psychoneurological institution. This diagnosis was established by a dermatovenerologist during an annual periodic medical examination in 2009. Total (generalized) skin lesions were observed in the form of erythroderma and massive layers of scale crusts. The fact that scabies was diagnosed a year earlier deserves attention; it can often be observed in the form of hospital outbreaks in medical and preventive institutions of this profile. The relapse of the disease could have occurred as a result of inadequate control of the patient's therapy and his environment - other patients of the boarding school, and also be caused by insufficient hygiene skills and features of the immune defense of the skin in patients with Down syndrome.

Keywords

clinical case, Norwegian scabies, hyperkeratotic layers, massive scale crusts, Down syndrome, immunological features of the skin

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RELEVANCE

Scabies is a contagious dermatological disease caused by the invasion of the scabies mite into the epidermis. Unlike classic common scabies, in which approximately 10-15 mites live on human skin, laying 60-90 eggs over 30 days, in Norwegian scabies their number is in the thousands. Norwegian (crusted, crusted) scabies is caused by hyperinvasion of Sarcoptes scabiei and the inability of the host's immune response to control the reproduction of mites [1, 2, 3]. Comorbid conditions (tuberculosis, diabetes mellitus, HIV infection, intake of immunosuppressants and chemotherapeutic drugs, as well as decreased cognitive functions against the background of psychoneurological pathologies) lead to the development of this type of scabies [1, 2, 4].

Norwegian scabies was first documented in Norway in a patient with leprosy (Boeck C. W. and Danielssen D. C., 1847) [1, 2]. The overwhelming majority of clinical cases of Norwegian scabies presented in the scientific literature describe this form of acariasis in patients with Down syndrome [3, 5, 6, 7]. These patients are a special risk group, since they have problems with personal hygiene against the background of decreased sensory and cognitive functions. In addition, there is data on the peculiarities of the structure and immunity of the skin in people with trisomy 21, which reduce the ability of the skin to self-cleanse [8].

Diagnosis of Norwegian scabies is often delayed, since the clinical picture differs from the classical form of the disease: instead of typical itching, rashes with hyperkeratotic layers come to the fore [2, 3, 4, 9]. This leads to long-term persistence of infection and an increased risk of hospital outbreaks, especially in psychiatric and psychoneurological hospitals [6, 10, 11]. Understanding the characteristics of the course of Norwegian scabies in patients with Down syndrome is important for dermatovenerologists, infectious disease specialists and general practitioners. Timely diagnosis and treatment not only improve the prognosis for a particular patient, but also prevent epidemiological consequences [2]. This article presents a clinical case of Norwegian scabies in a patient with Down syndrome.

CASE DESCRIPTION

Patient D., born in 1973, residing in the KOGBUSO "Klimkovskiy boarding house" in the village of Klimkovka, Kirov region, was preliminarily diagnosed with "Norwegian scabies" in 2009 during a periodic medical examination; a scabies mite was found in a scraping from 10.06.2009, which confirmed the diagnosis.

From the anamnesis of the disease: the diagnosis of "scabies" was first made during an annual preventive medical examination in 2008 by a visiting dermatovenerologist. According to the current clinical recommendations, etiotropic treatment was prescribed - 20% benzyl benzoate emulsion on the 1st and 4th days of treatment. A follow-up examination by a dermatovenerologist at the Central Regional Hospital was recommended. When interviewing the patient's guardians, it was found that after the treatment, they did not consult a dermatovenerologist, and did not take a scraping for scabies mites. Similar symptoms were observed in other residents of the boarding school.

A relapse of the disease in this situation may be associated with reinfection from roommates, or may be the result of insufficient treatment and lack of monitoring of therapy in 2008.

From the anamnesis of life: not married, does not have sex, due to the diagnosis of "Down syndrome", lives in a specialized boarding house in the village of Klimkovka. According to the guardians: bad habits, blood transfusions, surgical interventions, chronic diseases, allergic reactions, drug intolerance, human immunodeficiency virus (HIV), tuberculosis, hepatitis "A", "B", "C", acute intestinal infections (AII), malaria, measles, previously suffered sexually transmitted infections (STIs) are absent.

Past diseases: acute respiratory viral infections (ARVI), chickenpox.

Status localis: pathological skin process is widespread, symmetrical, inflammatory in nature.

On the skin of the forehead and scalp there are massive layers of grayish-brown scale crusts up to 1 cm thick, dotted with a large number of deep cracks filled with serous-hemorrhagic discharge (Fig. 1 and 2). The pathological process visually resembles a shell. Similar thick scale crusts are also observed in the area of the left wrist, hands of both hands and feet. In addition, in the parietal and suboccipital regions there are extensive bleeding erosions, as a result of independent mechanical removal of crusts. (Fig. 3). The skin of the face is hyperemic, infiltrated with layering of scales (Fig. 1 and 2).

In the area of the upper back and the back of the neck, against the background of congestive hyperemia and lichenification, multiple confluent papular elements are observed, in places covered with yellowish-gray crusts. Positive symptoms of Michaelis (papules, excoriations and hemorrhagic crusts on the skin of the sacral region), Sezary (palpably determined elevated scabies passages), Ardi-Gorchakov (purulent-hemorrhagic crusts on the extensor surface of the elbow joints) are noted (Fig. 4).

The nail plates of the hands and feet with phenomena of subungual hyperkeratosis, dirty yellow color, the free edge is corroded (Fig. 5 and 6).

Treatment:

The patient received therapy at the place of stay in the boarding house. As a keratolytic agent, 10%-2% sulfur-salicylic ointment was prescribed in the morning for 7 days. Etiotropic treatment with 20% benzyl benzoate emulsion on the 1st and 4th days. To prevent secondary infection, foci and excoriations were treated with a solution of Fukortsin, ceftriaxone 1.0 intramuscularly once a day for 5 days.

On the 7th day (after the crusts came off), he began to receive treatment only with scabicides: 20% benzyl benzoate emulsion on the 1st and 4th days according to the scheme [12].

As a result of the treatment, the nodular elements resolved, leaving minor hyperpigmentation, erosions epithelialized, and scale crusts came off. The nail plates of the hands and feet were treated. After healing, it is recommended to use emollients, products with urea, ceramides, essential fatty acids, phospholipids to eliminate hyperkeratosis, dryness, and strengthen the skin's protective barrier [2, 10].

DISCUSSION
Norwegian scabies is most often found in patients with immunodeficiencies, cognitive and mental disorders, with concomitant chronic dermatoses, as well as neurological diseases accompanied by disturbances of pain, tactile and other types of sensitivity. [13, 14] In this article, we attempted to establish the causes of predisposition to the development of Norwegian scabies in patients with Down syndrome.
There are limited data on genetic abnormalities secondary to trisomy 21 and affecting the immune system, for example, on the possible consequences of overexpression of genes, primarily SOD1 and RCAN1. [15] Immune system abnormalities associated with Down syndrome include mild to moderate T- and B-cell lymphopenia with marked reduction in naïve lymphocytes, impaired mitogen-induced T-cell proliferation, decreased specific antibody response to immunization, and defects in neutrophil chemotaxis. It has been suggested that secondary immunodeficiency may be due to metabolic or nutritional factors, particularly zinc deficiency. [16] Overexpression of the free radical metabolism regulating gene SOD located on chromosome 21 is a consequence of trisomy 21, resulting in excess formation of hydrogen peroxide, which causes the release of cytotoxic hydroxyl radicals. This, in turn, causes oxidation of cell membrane lipids, altering the structure and function of the skin [15, 16].
The skin in Down syndrome is subject to premature atrophy, as a result of which it becomes dry, poorly elastic, and prone to injury. [15, 16, 17, 18, 19] The combination of immune and genetic dysregulation leads to increased susceptibility to bacterial, fungal, and parasitic infections, including scabies [18, 19].

Conclusion

In conclusion, it should be noted that Norwegian scabies, as a rare and severe form of sarcoptic infection, often develops in patients with severe immunological disorders. In people with Down syndrome, the tendency to weaken the immune defense of the skin, caused by genetic and systemic changes, may play a key role in predisposition to this pathology. Disruptions in the barrier function of the skin, as well as an imbalance in the immune response, create favorable conditions for the uncontrolled reproduction of the Sarcoptes scabiei mite, which leads to the development of a severe clinical picture. Understanding this relationship emphasizes the importance of early diagnosis and a comprehensive approach to the treatment of Norwegian scabies in patients with Down syndrome, including strengthening the skin barrier and immune function [20, 21, 22].

About the authors

Sergei V. Koshkin

Kirov State Medical University; Kirov Regional Dermatology Hospital

Email: koshkin_sergei@mail.ru
ORCID iD: 0000-0002-6220-8304
SPIN-code: 6321-0197
Scopus Author ID: 57193110754

MD, Dr. Sci. (Med.), Professor, Head of the Department of Dermatovenereology and Cosmetology, Kirov State Medical University

Россия, 610027, Russia, Kirov, st. K. Marx, 112; 610000, Russia, Kirov, st. Semashko, 2a