Skin, being a human’s biggest organ, plays many functions; connects the body with the external environment and, at the same time, insulates from it. Skin plays a key role in water management and thermoregulation.
Skin consists of the following layers (beginning with the outermost layer):
- Epidermis – external layer having protective and reproductive function; it contains pigment (melanin) which gives color to hair and skin.
- Cutis vera – middle layer, contains receptors, blood vessels, nerves and glands, e.g. sweat glands, as well as hair roots. This is a nutritive and supporting layer (from 1 to 3 mm thick).
- Hypodermis, tela subcutanea is located under the skin and is composed of loose connective tissue proper. Hypodermis contains fat cells and insulates against sudden temperature changes.
Stratum corneum is the main protective element of skin; it is a membrane between the external and internal environments. Comparing to total thickness of skin, stratum corneum is relatively thin. It is the most visible outer layer that shows the condition and appearance of skin. Stratum corneum protects deeper layers of skin/epidermis against penetration of xenobiotics, pathogenic microorganisms and harmful UV rays.
The closer to the outer surface, the less compact is the structure of the stratum corneumIndividual cells divide, loosen up and peel off in small quantities. This is an unnoticeable, constant process of shedding skin. An adult person loses approx. 10 g of skin daily. New cells replace old and damaged ones and make small defects in the epidermis disappear over time without a trace. The process of revival of the epidermis in young people lasts on average 26-28 days. With age the process becomes longer.
The structure of stratum corneum and its ability to block water is the key factor in providing a proper level of moisturization. Correct amount of water in stratum corneum influences proper process of shedding skin, functioning of enzymes, and enhances creation of moisturizing substances. The Stratum corneum is responsible for blocking water and it regulates natural flow of moisture from deeper layers.
To a certain degree genetic predispositions influence the appearance of skin, but its condition depends on methods of care, both internal and external. Skin’s condition is also influenced by environmental factors and by lifestyle. Diet influences appearance of skin as well as its reactivity to various chemical and physical stimuli. The appearance of skin reflects the condition of the human body. That is why incorporating a healthy lifestyle, avoiding stress and providing proper moisturization affects the appearance of skin. Hormones, bacteria or medications are only some of the factors influencing the growth of spots, pimples or development of skin disease. Everyone has been affected by such ailments at some point.
Human skin is sensitive to contact with various chemicals and susceptible to reactions that are a consequence of the functioning of human body, e.g. stress or improper diet.
By taking the right course of action, one can delay the inevitable aging of skin, treat acne, clear up discolorations or protect themselves against cancer. In the case of chronic skin disorders it is often necessary to undergo dermatological treatment. Skin disorders and ailments often cause exclusion from society for the fear of infection. Acne, psoriasis or atopic dermatitis can lead to anxieties or even to depression.
The most common skin problems are:
1. Atopic dermatitis
Atopic dermatitis is a chronic disorder with a genetic background. It occurs during childhood and is characterized by eczema with intense itch, red patches, inflammation, excessive dryness of skin and lichenificatio.
Psoriasis is a chronic immune-mediated skin disease, characterized by increased proliferation of epidermis and the presence of red patches covered by silver scale. The disease is of relapsing/remitting character, and remission can last from a few to several years. Psoriasis can affect various areas of the body, including head and nails. Its symptoms include not only changes to the skin but in some cases the disease affects joints.
There are four basic types of psoriasis:
- Psoriasis vulgaris
- Psoriasis pustulosa
- Psoriasis arthropatica
- Erythrodermia psoriatica
Psoriasis vulgaris is the most common type, with scaly red patches located on elbows, knees, lower back and on the edge of scalp.
Psoriasis patients should take extra skin care to avoid pathogenic changes in slightly injured areas.
3. Acne Vulgaris
Acne vulgaris is a skin disease which occurs during puberty when sebaceous glands become overactive. The course of the disease is also influenced by exogenous factors.
Acne vulgaris manifests in four basic forms which lead to pathogenic changes:
- Overproduction and changes in composition of sebum
- Disorders in growth and multiplication of cells covering sebum gland duct
- Multiplication of Propionibacterium acnes
- Inflammatory reaction
4. Seborrhoeic dermatitis
Seborrhoeic dermatitis is a chronic inflammatory skin disorder affecting hair-covered areas of skin or sebaceous-gland-rich areas of skin (face, torso). It manifests in redness and excessive peeling off. The disorder becomes intensified by e.g. high temperature, excessive sweating, and diabetes. In some patients the disease can be relapsing, particularly during autumn and winter.
In atopy and many skin inflammations, Transepidermal Water Loss (TWL) can be observed, which results in lower epidermis barrier. Consequently skin is exposed to harmful external agents and it is easily irritated and damaged.