Leather.In a child, especially in the 1st year of life, the skin has a number of morphological and functional features that largely distinguish it from the skin of adults. These differences make it possible to understand and explain the frequency of skin lesions and the characteristics of their course at an early age. In a healthy child, the skin is smooth, velvety, pale pink. It is well supplied with blood due to the developed capillary network. The blood vessels are wide and easily permeable. The stratum corneum is thin and consists of 2-3 layers of weakly interconnected and constantly shedding cells. The main (germ) layer is well developed. Associated with this is the high ability of the child's skin to recover (regenerate). The dermis consists of papillary and reticular layers, in which the connective base and muscle fibers are developed. The basement membrane, located between the epidermis and the dermis, is represented by loose fiber and does not provide a strong connection between the main layers of the skin, which leads, in case of its diseases, to an easy separation of the epidermis and exposure of the dermis. skin functions. Due to the morphological immaturity of the skin of her protective the function is insufficient - the skin is extremely vulnerable and prone to maceration, accessible to the harmful effects of chemical irritants, easily infected, often being the entrance gate of infection. Therefore, when caring for a child, mothers and attendants must observe the strictest cleanliness and asepsis, and avoid the use of ointments containing irritating and easily absorbed substances at an early age. Also imperfect thermoregulatory skin function. Due to the insufficient development of the thermoregulatory function of the central nervous system and the intense return of heat and moisture through the skin surface, children of the 1st year of life do not retain a constant body temperature: the child easily overheats or overcools. Sweat glands are involved in thermoregulation of the body. However, in the first days of life, due to the immaturity of the sweating centers of the brain, they do not function, their ducts are poorly developed, and the gaps are closed by epithelial cells. Sweating begins at 3-4 months and appears at a higher temperature than in older children. Given the insufficient heat-regulating function of the skin, the child should be protected from both cooling and overheating. excretory the function of the skin is sufficiently developed due to the thin epidermis, good blood circulation and a relatively large surface of the skin. Respiratory function, the skin at an early age is more significant than in adults. The full functioning of the skin as a respiratory organ can only be ensured with careful care of the child with regular hygienic baths. In the skin under the influence of ultraviolet rays, vitamin synthesis occurs D , which plays an important role in calcium phosphorus metabolism, especially in children of the 1st year of life. For execution vitamin-forming functions, it is necessary to observe the daily regimen with sufficient exposure of the child to the fresh air. The skin of a newborn is covered with primordial lubrication. It promotes the passage of the child through the birth canal of the mother and protects him from external influences. The composition of the lubricant includes the secret of the sebaceous glands, which begin to function during fetal development. Significant secretion of the sebaceous glands in the neonatal period can lead to the appearance of seborrhea (“baby cap”) on the scalp and whitish-yellow dots on the nose and cheeks. The hairline on the head of a newborn is usually well developed, but due to the lack of a core, the hair is very soft. After 6-8 weeks, they fall out and are replaced by new ones. Thin fluffy hair that covers the body of a child in the first months of life is later replaced by permanent hair. Subcutaneous fat. In full-term children, it is well developed and intensively grows in the first 6 months of life. In newborns, it is better expressed on the cheeks, upper and lower extremities and worse on the abdomen. The composition of fat in young children differs in chemical composition from adult fat. It has more solid fatty acids with a high melting point. As a result, the subcutaneous fat layer can become dense when the child cools down and develops conditions such as sclerema and scleredema. The composition of adipose tissue depends not only on the age of the child, but also on its location. This explains the regular sequence in the accumulation and disappearance of fat with an increase in body weight or its fall. The subcutaneous fat layer first of all disappears on the abdomen, then on the torso, limbs and, last of all, on the face. The increase in the mass of adipose tissue in the 1st year of life is due to an increase in the number of fat cells. Therefore, systematic overfeeding of infants can lead to persistent and severe obesity in the future.

"I approve"

Head of the Department of Pediatrics,

MD Professor

A.I. Kuselman

__________________

"____" _____________2006

Anatomical and physiological features of the skin, subcutaneous fat. Semiotics of defeat.

The student must know:

Skin AFO.

Method for examining the skin.

major skin disorders.

AFO of the subcutaneous fat layer.

The main symptoms of violations of the subcutaneous fat layer.

Questions for independent work:

The concept of scleroma and scleroderma (see the textbook "Propaedeutics of childhood diseases" A.V. Mazurin //M// 2004, page 139)

Purpose of the lesson:

Learn to identify pathological changes in the skin and subcutaneous fat layer most common in children.

The student must be able to:

Inspect and palpate the skin of the child;

identify the main symptoms of skin lesions;

Assess the development of the subcutaneous fat layer, the correctness of its distribution;

determine soft tissue turgor;

Skin and subcutaneous tissue

Functions of the skin in a child are due mainly to their anatomical features.

The functional features of the skin include:

most intensively developed in a child respiratory function skin, in a newborn it is 8 times stronger than in an adult;

pigment-forming function- production of melanin;

resorption (suction) function in infants it manifests itself more intensively, which should not be forgotten when prescribing skin medications to them;

skin - sense organ; it contains numerous receptors. Almost all reflexes

newborns are evoked by touching his skin;

excretory function the skin of an adult is allocated 700-1300 ml of sweat;

in young children is underdeveloped;

thermoregulatory function in a newborn child, it is poorly developed, which must be remembered when caring for a baby (bathing, swaddling); this function fully enters into its activity only a few months after birth;

skin is protective barrier, however, in infants this function is weakly expressed; vitamins, enzymes, biologically active substances are formed in the skin;

for the doctor the skin is a sign of violations of the state of internalbodies(hyperthermia, water metabolism disorders, etc.).

Anatomical and physiological features skin in a child have pronounced differences from an adult, as well as in children of different ages. It consists of two main layers: the epidermis (basal, granular and stratum corneum) and the dermis.

Distinctive features:

the thickness of the different layers of the child's skin is 2-3 times less than that of older persons;

a feature of the basal layer of the epidermis in a newborn is insufficient melanin formation , what causes lighter skin color immediately after birth. In newborns of the black race, immediately after birth, it is light and has a reddish tint.

the granular layer of the epidermis in infants is very weakly expressed, and in newborns it is absent in the cells keratohyalin, giving the skin a white color; all this is due to the transparency and pink color of the child's skin;

in young children, the horny thin layer consists of 2-3 layers of keratinized cells; it is loose, prone to slight injury, saturated with water;

the dermis in children is distinguished by the advantage of cellular elements, in an adult - by the advantage of a fibrous structure.

Only at the age of 6, the histological structure of the skin approaches the composition of an adult.

Skin color and appearance

In a newborn, the skin is pale cyanotic in color, somewhat edematous, in the area of ​​​​the shoulder blades covered with vellus hair (embryonic fluff-lanugo). After birth, the surface of the dermis is covered with a thick layer of cheesy original lubricant (vernixcaseosa), which includes desquamated epidermis, fat, cholesterol, etc. The skin is cleared of lubrication and a few hours after birth acquires a reddish color with a slight cyanotic tint - this is called physiological catarrh of the newborn (physiological erythema-erythemaneonatorum). It is expressed in the first two days of a child's life and is especially characteristic of premature babies.

On the second or third day of life in most children, the skin acquires a yellowish tint - physiological jaundice of the newborn (icterusneonatorumtransient hyperbilirubinemia). Hyperbilirubinemia is an increase in the amount of bilirubin in the blood serum (it is noted in newborns due to the physiological destruction of red blood cells and, on the basis of this, the formation of bilirubin from released hemoglobin: the immaturity of the liver enzyme systems plays an important role). On the 3rd-4th day of a child's life, the average amount of bilirubin is 100-140 µmol/l. In 1/3 of newborns, this figure is less than indicated, in 1/3 it rises to 170 µmol/l.

Yellowness of the skin is observed in about 2/3 of children. It occurs in full-term newborns, when the amount of bilirubin exceeds 50 μmol / l, and in premature infants - more than 85-100 μmol / l.

disappearsicterusneonatorumfor 7-10 days of life.

The delay in physiological jaundice until the end of the first month of life (it is called conjugative jaundice) requires additional examination and treatment.

The skin has two main layers - epidermis And dermis. In newborns and young children, the thickness of the epidermis ranges from 0.15 to 0.25 mm (in adults, the thickness of the epidermis is from 0.25 to 0.36 mm). The epidermis has three layers: basal, granular And horny.

Basal layer The epidermis is well defined and consists of two types of cells, among them - melanocytes, which contain melanin. Newborns do not have enough melanin, which is why the skin of babies at birth is lighter than at a later age. Even people of the Negroid race have children with lighter skin, only after a while it begins to darken.

Granular layer epidermis in newborns is also weakly expressed. This explains why babies have a significant translucency of the skin, as well as its pink color. In newborns, the cells of the granular layer of the epidermis do not have the protein keratohyalin, which provides natural skin color for the white race.

stratum corneum the epidermis is much thinner in newborns than in adults, but the cells of this layer contain much more fluid, which gives the appearance of a greater thickness of this layer. The boundary between the dermis and epidermis is tortuous, uneven, and the substance between these layers is poorly developed. It is for this reason that in some diseases the epidermis separates from the dermis, forming blisters.

TO skin appendages include nails, hair, sweat and sebaceous glands.

On the body of a newborn hair fluffy first. Some time after birth, the vellus hair falls out and is replaced by permanent hair. In newborns, hair on the head is usually of different lengths and colors (in most cases black), but they do not determine either the color or the splendor of the future hair. In children, hair grows slowly, and eyelashes, on the contrary, quickly: at the age of 3-5 years, the length of the eyelashes in a child is the same as in an adult. Therefore, there is an opinion that children have longer eyelashes, which, together with large eyes, gives the child's face a specific childish expression.

In full-term babies at birth nails reach the fingertips, which is also one of the criteria for assessing the maturity and maturity of the child.

Sebaceous glands located on all areas of the skin, except for the soles and palms. The sebaceous glands in newborns can degenerate into cysts, especially in the nose and adjacent areas of the skin, resulting in the formation of small yellow-white pimples, which are called milia (or milium). They do not cause much trouble and eventually disappear on their own.

In newborns sweat glands have underdeveloped excretory ducts. For this reason, sweating in young children does not occur fully. The formation of sweat glands ends at about 7 years of age. Also, in a small child, the mechanism of thermoregulation is completely undeveloped, which often leads to sweating when the ambient temperature drops.

Sweat glands are divided into apocrine and eccrine glands. Apocrine glands provide a specific smell, and eccrine- they just sweat. Apocrine glands in children appear at the age of 8-10 years and are located in the armpits and in the genital area.

subcutaneous fat layer children also have their own characteristics. The fat cells of a child contain nuclei and are much smaller than those of an adult. The ratio of the mass of subcutaneous fat to the total body weight in a child is greater than in adults, which determines the visual roundness of their body. In the abdominal and thoracic cavities, as well as in the retroperitoneal space in children, there are practically no accumulations of fat. Fat begins to accumulate there only by the age of 5-7, and during puberty its amount increases significantly. Another feature of adipose tissue in newborns and infants is that it takes part in the process of hematopoiesis. Also, newborns have a lot of brown fat, the function of which is the formation of heat, which is not associated with muscle contraction. Stocks of brown fat provide newborns with protection from moderate hypothermia for 1-2 days. Over time, the amount of brown fat decreases, and if the child is constantly hypothermic, brown fat disappears much faster. If a child is starving, white adipose tissue quickly disappears, and if the fasting period is very long - brown.

For this reason, premature babies, who have much less brown fat, require more thorough rewarming, as they are more prone to hypothermia.

At the time of puberty, girls and boys have different amounts of subcutaneous fat - in girls, 70% of adipose tissue is subcutaneous fat, and in boys - 50%. It is this factor that determines the roundness of the forms.

Adipose tissue in children is characterized by a number of features (Table 5-11).

At the end of the prenatal period and in the first year of life, the mass of adipose tissue increases as a result of an increase in both the number and size of fat cells (by 9 months of life, the mass of one cell increases 5 times). The thickness of the subcutaneous adipose tissue increases markedly from birth to 9 months, and then gradually decreases (by the age of 5, it decreases by an average of 2 times). The smallest thickness is noted at 6-9 years.

In puberty, the thickness of the subcutaneous fat layer increases again. In adolescent girls, up to 70% of fat is located in the subcutaneous tissue (which gives them roundness), while in boys, only 50% of the total fat is in the subcutaneous layer.

The skin is one of the main barrier systems of the body, which has morphological and functional differences in different periods of childhood and reflects the state of the internal organs and other systems of a healthy and sick child.

The skin is an indicator of the age of intrauterine development. So, skin furrows on the soles appear at 32-34 weeks in the upper part of the sole and go transversely. About 37 weeks. furrows occupy approximately 2/3 of the area of ​​the foot, mainly in the upper sections. By 40 weeks the entire foot is streaked with furrows. Vellus hair from about 20 weeks of fetal development covers the entire body of the fetus. Approximately from 33 weeks. they begin to gradually disappear, first from the face, then from the trunk and limbs. By 40 weeks vellus hair remains only in the area of ​​​​the shoulder blades, and by 42 weeks. disappear completely. The nipples and areolas of the mammary glands begin to protrude above the skin from the 34th week, from the 36th week you can feel the nodules of the glandular tissue (1-2 mm), the size of which is rapidly increasing.

Skin AFO:

1. In the skin of a child, as in an adult, the epidermis and dermis are distinguished, between which the basement membrane is located. The epidermis consists of a superficial thin stratum corneum, represented by 2-3 rows of weakly interconnected and constantly desquamating epithelial cells, as well as a basal layer in which epithelial cells grow, providing replenishment of keratinizing elements. The dermis, or the skin itself, consists of papillary and reticular parts. In the dermis, connective tissue, elastic and muscle elements are poorly developed. In an adult, the good development of the connective and elastic tissue of the basement membrane provides a close connection between the layers of the skin. In childhood, especially in newborns, the basement membrane is very delicate and loose, which determines the weak connection between the epidermis and dermis.
2. At the time of the birth of a child, his skin is covered with a rather thick layer of cheese-like lubricant. Cheese grease consists of fat, cholesterol, it has a lot of glycogen. It also contains a desquamated epidermis. After removing the lubrication and cleansing the skin from accidental contamination during passage through the birth canal, the skin of the newborn is somewhat edematous and pale. The initial pallor is then replaced by a reactive redness with a somewhat cyanotic tinge - the "physiological catarrh of the skin" of newborns; in premature babies, the physiological catarrh of the skin is especially pronounced.
3. Hair. They are quite developed, but do not have a hair follicle, which causes their easy loss and does not allow the formation of boils with a purulent shaft. The skin, especially on the shoulders and back, is covered with a vellus cover (lanugo), more noticeable in premature babies; eyebrows and eyelashes are poorly developed, in the future their growth increases.
4. Nails in full-term newborns are well defined and reach to the fingertips. In the first days of life, a temporary delay in nail growth occurs, which is manifested by the appearance of a transverse "physiological" feature on the nail plate.
5. The sebaceous glands are distributed throughout the skin, with the exception of the palms and soles. They are fully formed morphologically and begin to function already at the 7th month of the prenatal period and histologically do not differ from the structure in adults.
6. The number of sweat glands at the birth of a child is the same as in an adult. Underdevelopment of the excretory ducts of the sweat glands is associated with imperfection of sweating. The formation of the excretory ducts of the sweat glands is partially noted already at the 5th month of life, and completely ends only after 7 years. The formation of sweat glands on the forehead and head ends earlier. In this case, increased sweating often occurs, accompanied by anxiety of the child and baldness of the back of the head. Later there is perspiration on the skin of the chest and back. As the structure of the sweat glands and the autonomic nervous system matures, the perspiration threshold also changes. The adequacy of sweating develops during the first 7 years of life. Young children often respond by sweating to a decrease in ambient temperature and, as a rule, are unable to inhibit sweating when the temperature drops.
   Apocrine sweat glands in young children do not function at all. The beginning of their activity comes to light only about 8-10 years.
7. The protective function that protects the body from adverse external influences is also performed by the pigment melanin, which protects the body from excess ultraviolet rays. In newborns and young children, due to the weak development of the stratum corneum, low activity of local immunity, this function is not sufficiently developed, which determines the easier vulnerability of the skin.
8. Melanin also determines skin color, which is why babies are pink.
9. The pH of the skin is neutral, in adults it is acidic, resulting in the development of purulent diseases.
10. The thinness of the stratum corneum, the presence of a well-developed vascular system provide increased resorption function of the skin.
    At the same time, the excretory function associated with sweating is underdeveloped.
    This is the basis for the contraindication to the use of certain ointments, creams, pastes, since instead of a therapeutic one, a general toxic effect is possible. For the same reasons, the risk of infection through intact skin in young children is much greater than in older children.
11. The thermoregulatory function of the skin is poorly developed, since the formation of the centers of temperature regulation occurs only by 3-4 months; sweat glands are not functioning properly. As a result, overheating or hypothermia of the child easily occurs.
12. The respiratory function of the skin is hundreds of times stronger than in adults. It is provided with an abundance of circulatory capillary network, a thin layer of the epidermis, a peculiar structure of the vascular wall, which makes it quite easy for gases to diffuse through the vessel wall. The statement is correct: newborns “breathe” with their skin. Pollution of the skin turns it off from the breathing process, which negatively affects the well-being of a healthy child, worsens the course of the disease.
13. The skin plays an important role in providing mechanical, tactile, temperature and pain sensitivity due to the presence of a large number of various receptors in it. This allows us to consider the skin as one of the five sense organs. In the first month of life, due to the insufficient development of the organs of vision and hearing, the child “recognizes” the mother’s hands with the help of tactile perception. At the same time, excessive skin irritation (for example, wet and dirty diapers) can cause a newborn to worry, disturb his sleep, appetite, and develop malnutrition.
14. Synthetic function of the skin. The skin is actively involved in the formation of melanin pigment and anti-rachitic vitamin D3 under the influence of ultraviolet radiation.
15. Subcutaneous fatty tissue begins to form on the 5th month of intrauterine life and is deposited in the fetus mainly during the last 1.5-2 months. pregnancy.
    By birth, subcutaneous adipose tissue is more developed on the face (fatty bodies of the cheeks - Bish's lumps), limbs, chest, back; weaker - on the stomach. In young children, the subcutaneous fat layer averages 12% of body weight, in adults it is normal - no more than 5%.
    The subcutaneous fat layer is better expressed in full-term newborns. In premature babies, it is the less, the greater the degree of prematurity. Adipose tissue performs various functions: mechanical protection, thermal insulation, thermogenesis, energy, storage of soluble fats. In newborns and infants, the subcutaneous adipose tissue differs in a number of features: fat cells are smaller and contain nuclei, the ratio of the subcutaneous fat layer in 1-year-old children to body weight is relatively higher than in an adult. In the chest, abdominal cavities, in the retroperitoneal space, there is almost no accumulation of fatty tissue. In the subcutaneous tissue of these children, there are areas of embryonic tissue that have a fat-accumulating and blood-forming function.
16. A feature of the subcutaneous adipose tissue of the fetus and newborn is brown adipose tissue (1–3% of body weight).
    The main function of brown adipose tissue is the so-called non-shivering thermogenesis, i.e., heat production that is not associated with muscle contraction. Brown adipose tissue has the maximum capacity for heat production in the first days of life: in a full-term baby, it provides protection from moderate cooling for 1-2 days. With age, the ability of brown adipose tissue to produce heat decreases.
17. The formation of lymph nodes begins from the 2nd month of intrauterine life, and ends in the postnatal period.
    In newborns, the capsule of the lymph nodes is very thin and delicate, the trabeculae are underdeveloped, so their palpation is difficult. Lymph nodes are soft, buried in loose subcutaneous fatty tissue. By one year, the lymph nodes are already palpable in most children. Together with a gradual increase in volume, their further differentiation occurs.
    The reaction of the lymph nodes to various agents, most often infectious, is detected in children, usually from the 3rd month of life. In children of the first two years of life, the barrier function of the lymph nodes is low, which explains the frequent generalization of infection at this age (development of sepsis, meningitis, generalized forms of tuberculosis, etc.). Insufficient development of the lymphoid apparatus of the digestive tract by the time of birth causes a slight susceptibility of children, especially the first year of life, to intestinal infections, early allergization of the body by the enteral route. In the preschool period, the lymph nodes can already be a mechanical barrier to respond to the introduction of pathogens of infectious diseases with an inflammatory reaction. Children of this age often have lymphadenitis, including purulent and caseous (with tuberculosis infection). By the age of 7-8, the possibility of immunological suppression of infection in the lymph node appears. In older children, pathogens enter the lymph nodes, but do not cause suppuration or other specific changes.
18. thymus. After the birth of a child, the thymus continues to increase in size until puberty. By this time, its mass reaches 30-40 g. Starting from the 7th day after birth, the same thymus mode of operation is established as in adults. The heyday of his activity comes to 3 - 4 years, after which it weakens. By the puberty period, thymus degradation occurs, its lobules are replaced by adipose tissue. At the same time, the weakened immunological and endocrine functions of the thymus remain until old age.
19. Spleen a relatively large unpaired organ weighing about 150 g, the spleen does not complete its development by birth: the trabeculae and capsule are poorly developed. At the same time, the lymphatic follicles are well developed and occupy most of the organ. The mass of the spleen increases with age, but throughout childhood remains a constant value in relation to the total body weight, amounting to 0.25 - 0.3%.
20. Peyer's patches. In humans and animals there is quite a lot of "free" lymphoid tissue, not enclosed in a connective tissue capsule and located in the walls of the digestive, respiratory and urogenital organs. Lymphoid tissue may present as diffuse infiltration or as nodules. In the small intestine, such nodules are called Peyer's patches. The formation of Peyer's patches occurs at the earliest stages of ontogeny. By the time of the birth of the child, they are well expressed.