Dermatology and veneorology

DERMATOLOGY
AND
VENEREOLOGY
TUTORIAL
Under the general editorship of Professor O.A. Pritulo
Moscow
INFRA-M
2025

УДК  616.5(075.8)
ББК  55.8я73
	
Д36
R e v i e w e r s:
Kubyshkin A.V., Doctor of Medical Sciences, Professor, Head of the 
Department of General and Clinical Pathophysiology, Vice-Rector for 
Scientific Activities (Medical Institute of the Order of the Red Banner of 
Labor named after S.I. Georgievsky, Crimean Federal University named 
after V.I. Vernadsky);
Karimov I.Z., Doctor of Medical Sciences, Professor, Head of the 
Department of Infectious Diseases (Medical Institute of the Order of 
the Red Banner of Labor named after S.I. Georgievsky, Crimean Federal 
University named after V.I. Vernadsky)
 
Dermatology and venereology  : tutorial  / under the gen. ed. of 
Д36	 	
Prof. O.A.  Pritulo.  — Moscow : INFRA-M, 2025.  — 214 p.  — (Higher 
Education). — DOI 10.12737/2021364.
ISBN 978-5-16-018539-2 (print)
ISBN 978-5-16-111531-2 (online)
The tutorial contains data on the history of dermatovenereology, modern 
concepts of anatomy, physiology, pathomorphology of the skin and its 
appendages. Considerable attention is paid to the practical skills that the 
student must master when studying the course of dermatovenereology. The 
main issues of the clinic, diagnosis, differential diagnosis, prevention and 
treatment of the most important skin diseases and sexually transmitted diseases 
are described. In addition, situational tasks are given after each topic. Separate 
sections are devoted to writing a medical history and questions for independent 
extracurricular work of students.
The 
content 
corresponds 
to 
the 
program 
of 
the 
discipline 
“Dermatovenereology”.
The tutorial is intended for 4th year students of higher medical educational 
institutions. 
УДК  616.5(075.8)
ББК  55.8я73
ISBN 978-5-16-018539-2 (print)
ISBN 978-5-16-111531-2 (online)
©  Team of authors, 2023

Team of authors
Pritulo Olga A., Doctor of Medical Sciences, Professor, Head of the 
Department Dermatovenereology and Cosmetology  (Medical Institute 
of the Order of the Red Banner of Labor named after S.I. Georgievsky, 
Crimean Federal University named after V.I. Vernadsky);
Prokhorov Dmitry V., Doctor of Medical Sciences, Professor, Professor of the Department Dermatovenereology and Cosmetology 
(Medical Institute of the Order of the Red Banner of Labor named after 
S.I. Georgievsky, Crimean Federal University named after V.I. Vernadsky);
Maraqa Marvan Ya.N., Candidate of Medical Sciences, Associate 
Professor, Associate Professor of the Department Dermatovenereology 
and Cosmetology (Medical Institute of the Order of the Red Banner 
of Labor named after S.I. Georgievsky, Crimean Federal University 
named after V.I. Vernadsky);
Ngema Maria V., Candidate of Medical Sciences, Associate Professor, 
Associate Professor of the Department Dermatovenereology and Cosmetology (Medical Institute of the Order of the Red Banner of Labor 
named after S.I. Georgievsky, Crimean Federal University named after 
V.I. Vernadsky);
Kuznetsova Marina Yu., Candidate of Medical Sciences, Associate 
Professor, Associate Professor of the Department Dermatovenereology 
and Cosmetology (Medical Institute of the Order of the Red Banner 
of Labor named after S.I. Georgievsky, Crimean Federal University 
named after V.I. Vernadsky);
Kaud Dia, Candidate of Medical Sciences, Associate Professor, Associate Professor of the Department Dermatovenereology and Cosmetology (Medical Institute of the Order of the Red Banner of Labor 
named after S.I. Georgievsky, Crimean Federal University named after 
V.I. Vernadsky);
Ispiryan Mikhail B., Candidate of Medical Sciences, Associate Professor, Associate Professor of the Department Dermatovenereology 
and Cosmetology (Medical Institute of the Order of the Red Banner 
of Labor named after S.I. Georgievsky, Crimean Federal University 
named after V.I. Vernadsky).
3

Introduction
Dermatovenereology is a science studying causes, clinical manifestations and methods of treatment of skin and sexually transmitted 
diseases. Study of this subject is very important for the doctor today, 
especially now, when family medicine takes the leading position in the 
general health care. Knowledge of this discipline gives an opportunity 
to reveal syphilis on time, differentiate skin diseases from infectious 
ones, and make a diagnosis of pemphigus and interstitial disease being 
a serious danger for the life of patients.
This manual consists of thirteen themes, questions for independent 
students’ work, and practical skills for students. The book includes 
data of dermatology development, modern notion of anatomy, physiology, pathomorphology of skin and its appendages. Much attention is 
devoted to the practical skills of students, which every student must 
master studying dermatovenereology course. Main problems of clinics, 
diagnostics, differential diagnostics prophylaxis, and treatment of the 
most important skin and venereal diseases dermatological aspects of 
HlV-infection.
Besides, situational tasks and test questions are added at the end of 
each theme. Steps of medical history taking and independent students’ 
work are included into the book. 
4

CONTENT MODULES
Content module 1.
SKIN
1.1. SKIN ANATOMY AND HISTOLOGY
Skin is an external body layer, independent metabolically active 
organ. Its size is 1.6–1.8 m2. Its weight is approximately 16–20% of the 
total body weight. Human skin consists of epidermis, dermis, and hypodermis. There are also additional skin components such as hair, sweat, 
and sebaceous glands. Epidermis is an external skin layer. It consists of 
continuously changing epithelial cells (epitheliocytes, keratinocytes), 
which are always in the process of differentiation beginning with the 
lower slightly differentiated basal layer and continuing in the direction 
of the upper corneous layer. Epidermis consists of several types of cells 
having different embryonic origin — epitheliocytes, melanocytes, intraepidermal macrophages (Langerhans’ cells), and Marcellus’ cells and is 
divided into 5 layers — basal, spinous, granulated, lucid and corneous 
ones reflecting different stages of elements differentiation.
Cellular homeostasis support in epidermis totally depends on the 
correlation between the cells being formed and dying ones. Many factors make an influence on these processes: the level of interactions of 
epitheliocytes with other cells of epidermis; the quality of epitheliocytes 
adhesion with each other and basal membrane; different skin diseases; 
age and sex of the human being; climatic conditions. Epidermis doesn’t 
have absolutely estimated thickness. It varies in different body parts: in 
the palm area it is about 0.1 mm, on the soles it is from 0.8 to 1.4 mm; 
on the rest body parts it is less than 1mm.
Basal layer (stratum bazale) — epitheliocytes located on the basal 
membrane are embryonic cells. Merkel cells and melanocytes are also 
in the basal layer. Basal cells are located on the basal membrane and 
have a cylindrical form. Their nucleuses are oval by shape, intensively 
colored with hematoxylin and rich in chromatin. Numerous organelles: 
mitochondria, Golgi complex, ribosomes, pol-iribosomes, lysosomes, 
centrioles, endoplasmic reticulum, tonophilaments forming the cytoskeleton, and other additional components (melanin granules, fat 
5

drop) are found in cytoplasm. Basal cells proliferation and tonophilaments synthesis cause a great amount of ribosomes.
Cell-to-cell conjugation occurs at certain intervals due to the desmosomes located at the place of two neighboring cells contact This connection plays an important role in the structural integrity of epidermis 
and provides epitheliocytes regulation — their proliferation, movement 
and differentiation. Desmosomes contain 71% of proteins, 14% of carbohydrates and 10% of lipids, mainly cholesterol and phospholipids. 
Sometimes high mitotic activity of sprout cells makes them to be the 
target for different undesirable influences, for example, UV-radiation, 
and then it can lead to the tumor of skin.
Spinous layer (stratum spinosum) consists of 3–8 rows of cells, more 
differentiated than basal ones. Directly above the basal layer they have 
a polygonal shape and they become flat in the upper part of spinous 
layer. Spinous layer cells conjugate cell-to-cell like basal ones with the 
help of desmosomes, the number of which is greater and it gives them 
more strength. Ultrastructure of spinous cells is similar to that of basal 
one but it differs by more developed complex of tonophilaments, less 
organelle content, and pigment absence. Lamellar bodies appear in the 
upper part of spinous layer (lamellar granules, keratinocytes, Odland’s 
bodies) and locate on the cells periphery. They sometimes come in 
contact with plasmatic membrane or pass into the intercellular spaces. 
These organelles contain lipids, phospholipids, free sterols, ceramides, 
and glucosylceramides. Besides, a large amount of hydrolytic enzymes 
such as acid phosphatase, nucleoside diphosphatase, and phospholipases 
can be found in lamellar granules. Granules release their content into 
intercellular space forming epidermal lipid barrier. Internal epidermal 
macrophages — Langerhans’ cells are in the spinous layer too.
Granular layer (stratum granulosum) is presented by several lines 
of flat epitheliocytes. The cells of granulated layer are also connected by 
desmosomes. Their ultrastructure is similar to that of the lower layers 
but they lose intercellular contact layer on the border with corneous 
layer. Granular cells are identified by the typical cytoplasmic basophilic 
keratohyalin granules. Keratohyalin granules are tightly connected 
with the bands of tonofilaments and consist mainly of profilaggrin.
Clear layer (stratum lucidum) is well determined only on the palms 
and soles and consists of tightly located, prolonged and flat cells which 
don’t have any nucleus. In this layer epitheliocytes continue to synthesize and modify proteins and enzymes which take part not only in 
keratinization but also in the programmed cell destruction. As a result 
destruction of majority of the structures of granulated cells including 
6

their nuclei occurs. Such form of destruction morphologically and biochemically corresponds to apoptosis (programmed cell death).
Corneous layer (stratum corneum)
The final period of epitheliocytes life occurs in the corneous layer, 
where they turn into polygonal corneous cells without any nuclei. Such 
epitheliocytes got a name of “corneus squamae” Corneous layer protects 
the skin from liquid loss and external harmful substances penetration, 
and as well as mechanical insults. This layer is represented by the lines 
of corneous squamae and is more evident on the palms and soles. On the 
other parts of body it’s rather thin. Thickness of corneous layer depends 
on the sex, age and skin diseases presence. Squamae are separated from 
each other by intercellular spaces where desmosomes having a form of 
dense structures could be seen.
So epidermis is an integrated functional and anatomical skin structure. Conditional division of epidermis into several layers reflects, first 
of all, the process of epitheliocytes differentiation, having several stages: 
undifferentiated cells of basal layer are divided uninterruptedly and in 
addition, some amount of them is left on its place and another is differentiating and moving up; in the spinous layer cells become more differentiated and polygonal by form; in the granular layer the disintegration 
of cell nuclei and organelle happens; the process of differentiation of 
epitheliocytes is over in the corneous layer, in which the cells, being 
already corneus squamae (lamellae), independently exfoliate from the 
surface of the skin.
Dermis is the main component of skin connective tissue providing 
its flexibility and strength. It protects the organism from mechanical 
traumas, takes part in thermoregulation, and contains great number of 
vessels and nerves.
Dermis varies greatly in its thickness on different body parts: for 
example, it is very thin on the eyelids (0,6 mm), on the back, palms 
and soles it is very thick (3 mm and more). Totally dermis consists of 
cells and intercellular matrix. Two layers form the dermis: papillary and 
reticular. Besides differences in its position, they differ in the degree of 
connective tissue organization, number of fibrous structures, cells, nerve 
filaments, and vessels.
Papillary layer (stratum papillaris)
Collagen and elastic fibers are the base of this layer. A developed 
network of collagen and elastic fibers is formed due to the synthesis of 
a great number of fibroblasts, having a high level of metabolic activity.
7

Reticular layer (stratum reticularis) of dermis is formed mainly by 
collagen fibers of big diameter interlaced in big bundles. Mature elastic 
fibers interlace with bundles of collagen fibers and make dermis elastic 
and resilient. In healthy skin the size of elastic fibers and bundles of 
collagen of reticular layer increases nearer to hypoderma. Conditionally 
reticular layer is divided into upper and lower zones. It characterizes, 
first of all, the degree of difference in size and fibrous connective tissue 
feature. In the upper zone of reticular layer one can find mainly collagen fibers and bundles and also horizontally oriented elaunin elastic 
fibers. This region is rich with fibroblasts and other connective cells 
and in case of inflammation it is rich with leukocytes and lymphocytes. 
The upper zone has weaker mechanic properties as compared to deep 
lower zone of reticular dermis layer and, probably due to this fact, it 
is inclined to the development of different pathological processes, for 
example, to the loss of elastic fibers.
Dermis cells
Fibroblasts are the main dermis cellular type. They are mesenchymatous cells of connective tissue responsible for synthesis and lysis of 
fibrous joints and a plenty of other soluble compounds of intracellular 
matrix. One and the same fibroblast is capable to synthesize simultaneously several types of protein substances, e.g. collagen and elastin. Immature cells beginning from germ are sequentially differentiated until 
they reach their maturity and after that fibroblasts are subjected to degeneration or transformation. In dermis there are also histiocytes, the 
cells having stellate, dendritic or rather rare, spindle form. As a rule, 
they are found in large amounts in the papillary layer and upper part of 
reticular layer of the dermis. Histiocytes are immune component cells 
functioning as effector cells of afferent link of the immune response. In 
case of inflammatory diseases, e.g. psoriasis and eczema, the number 
of these cells increases, they become activated evoking expression of 
different inflammation markers. Another type of histiocytes — macrophages — have bone marrow origin. Penetrating into the bloodstream 
they turn into monocytes and then migrate to dermis where they are 
subjected to differentiation. Macrophages are active phagocytes, take 
part in the antigen processing and presentation of it to the immunecomponent lymphocytes. They have bactericidal and tumour effect due 
to the lysosome, superoxides, peroxides production, synthesize different 
growth factors, cytokines and other immune modulating molecules, and 
hemopoietins.
Tissue basophiles of dermis are the cells, predecessors of which 
were in the bone marrow (CD34+) and are distributed along all con8

nective tissue. Their greatest concentration is observed in the papillary 
layer of dermis. Tissue basophiles synthesize lots of mediators and at 
activation they are first effectors of allergic reactions. They also take 
part in the anti-tumor immune response and at tumor cells appearance 
they release tumor necrosis factor alpha-a substance having cytotoxic 
activity. Besides, tissue basophiles play an important role in the antiparasite protection, stimulate chemotaxis, activation and proliferation 
of eosinophils, intensify phagocytosis, change vascular tone and patency; stimulate connective tissue reparation.
Intercellular matrix of the dermis consists of 3 components: main 
substance, adhesive proteins and fibrous structures (collagen, elastic and 
reticular fibers). It performs different functions: provides mechanical 
contacts between cells, arranges firm structures, forms the ways of cellular transmission along which they can move. Main dermal substance 
is formed in a special way permitting the cells to move freely and regulate skin deformation. It is jelly-like amorphous substance consisting 
of glycosaminoglycans (GAGs), glycoproteins, proteoglycans, soluble 
collagen, and enzymes and split products. GAGs are linear polymers 
consisting of repeating disaccharides providing necessary hydration and 
viscosity to dermis. That’s why dermal saturation with GAGs in the 
young age keeps skin smooth, without wrinkles. An increase in GAGs 
level is observed during wounds healing on the skin, when the cells migration is one of the most significant points of the reparation process. 
Sulfated GAGs become prevalent at the time of dermis aging; and the 
level of hyaluronic acid being one of the most important components of 
GAGs begins to reduce. Proteoglycans are GAGs in the form of highmolecular polymers with the protein core to which hyaluronic acid is 
linked (hyaluronate). Their main role consists in the binding of growth 
factors and cytokines and in relieving of cells interaction with fibrous 
structures of territorial matrix. Due to these properties proteoglycans 
can influence proliferation, differentiation, reparation and skin morphogenesis.
Adhesive proteins
Fibronectin, laminin, thrombospondin (TSP) are the most important adhesive proteins. These polyfunctional proteins are capable to 
combine different compound components of intercellular matrix. Besides they also provide fixation of cells in the intercellular matrix interacting with membranous receptors-integrins. Adhesive proteins, due to 
the cells, collagen and elastic fibers adherence, take part in the process 
of homeostasis of derma promoting adhesion, migration, maturation, 
and differentiation of cells and other dermal components.
9

Fibrous structures of Collagen fibers
Collagen fibers are the main components of dermis and compose 
75% of dry mass of skin and provide its elasticity and firmness. By now 
more than 25 different types of collagen have been determined.
At one of the ends collagen molecule is attached by cross-links, the 
number of which increases while aging. Collagen molecules are capable 
of spontaneous aggregation with the formation of more complex structures-microfibrils and fibrils. Fibroblasts take part in the formation of 
collagen fibers. In the dermis of mature person interstitial fibrillar collagen (I, III and V type) is one of the largest collagen fractions: collagen 
type I constitutes approximately 80–90% collagen type III constitutes 
8–12%. Collagen type I is found in the reticular layer in great amount; 
collagen type III is found mainly in the papillary one.
Elastic fibers constitute 1–3% of dermis and form wide net. They 
are also found in the vessel walls of skin and membranes of hair follicles. 
A net of elastic fibers provides the skin with elastic, resilient properties. Elastic fibers are also produced with the help of smooth muscular 
cells in contrast with collagen, synthesized by only fibroblasts. Elastic 
fibers consist of two main components — elastin and fibrils. Elastins are 
polymer proteins having cross-linked structure and fibrils are glycoproteins. The elastic fibers production in dermis is very slow, but can be 
accelerated under ultraviolet radiation and in case of inflammation.
Reticular fibers (argyrophilic fibers) are found mainly at the border 
of dermis and epidermis, around the vessels, sweat and sebaceous 
glands, and hair follicles. These fibers are similar by their composition 
to collagen fibrils but have smaller diameters. The largest number of 
reticular fibers can be found in the healing wounds. At that time hyperproduction of collagen in fibroblasts occurs.
Hypodermis — subcutaneous cellulose — performs many functions — 
serves as a place of production and accumulation of fat. It is a reservoir 
of energy. It is “amortization pillow” in case of traumas and is characterized by dynamic metabolism of lipids. Maximal volume of fat tissue is 
located in hypodermis. Subcutaneous fat thickness differs depending on 
the part of the body. For example, its thickness in the anterior abdominal wall can reach 3 cm, and in the region of forehead it can be several 
millimeters. A transition zone located between fibrous connective tissue 
and hypodermic tissue saturated with fat is a boundary between deep 
dermal reticular layer and hypodermis. Despite of conditional boundary 
presence, hypodermis and dermis are firmly structurally and functionally joined by passing through them nerves and vessels and also by numerous cutaneous adnexa. Bulbs of the hair follicles as well as secretory 
portions of eccrine sweat glands are located in hypodermis. Adipocytes 
10