The skin barrier – A marvel of nature

The skin as a protective shield

The skin, including the delicate intimate skin, consists of three layers

With a surface area of about two square meters and a weight of 14 kilograms (in adults), the skin prevents excessive fluid loss and protects the body from drying out. At the same time, as a skin barrier, it shields the body from harmful external influences, including pathogens (bacteria, fungi, viruses), allergens, and other harmful substances such as chemicals and UV radiation. The skin’s barrier function is also the reason why medicine has only been able to deliver drugs into the bloodstream through the skin in a few cases (e.g., via patches, ointments, or gels).

The functions of the skin barrier apply equally to both the delicate intimate skin and the robust skin on the palms and soles. The better the skin is cared for and protected, the stronger its barrier function. That’s why the highly sensitive intimate skin should be gently cleansed and well-moisturized as part of intimate hygiene. Deumavan Washing Lotion and Deumavan Protective Ointment are recommended for this purpose.

The three layers of the skin (see diagram):

• Epidermis (outer layer)
• Dermis (middle layer)
• Subcutaneous tissue (hypodermis, fat layer)

The skin protects the body from harmful external influences (skin barrier), with the stratum corneum (horny layer), the outermost layer of the epidermis, playing the most crucial role.

The skin barrier renews itself daily

The epidermis consists of five different layers of cells. The lowest of these is the basal layer, named because it continuously generates new cells. These cells migrate to the visible surface of the skin, the stratum corneum (horny layer). Over several weeks, they pass through the upper layers of the epidermis, accumulating keratin, a key structural protein. Eventually, they become lifeless, flat corneocytes, which shed as tiny skin flakes—about 10 grams per day.

Interesting fact: In psoriasis (a chronic skin condition), epidermal cells renew themselves abnormally fast, leading to the characteristic thick, silvery-white skin flakes.

The skin barrier – A smart and complex shield

The defense mechanisms of the epidermis and its stratum corneum are incredibly diverse. Here are some key examples of its barrier functions:

• The stratum corneum, the visible surface of the skin, is the most important part of the skin barrier. It is structured like a brick wall (see diagram), making it almost impermeable to pathogens and foreign substances: flat corneocytes act as the “bricks,” held together by an intercellular lipid matrix that functions like “mortar.”
• The constant renewal of epidermal cells and their migration to the surface helps push out pathogens and foreign particles (such as tiny glass splinters) along with the shedding corneocytes.
• The acid mantle on the skin’s surface—formed by sebaceous and sweat glands in the dermis—has a slightly acidic pH, which helps prevent harmful microbes from multiplying.
• The epidermis has no blood vessels, which significantly enhances the skin barrier. Since there are no blood vessels in this layer, pathogens and foreign substances cannot directly enter the bloodstream. Blood vessels are found only in the dermis, which is why a wound bleeds only if it reaches at least that deep.
• The epidermis produces melanin, the pigment that determines skin color and protects the deeper skin layers from harmful UV radiation—explaining why the skin tans as a protective measure when exposed to sunlight.

A unique feature: Individual body odor

A special type of sweat gland, scent glands, contribute to each person’s distinctive body odor. These glands are mainly located in the armpits, intimate areas (both male and female), around the nipples, and on the scalp. Their secretions, combined with sweat, create a person’s unique scent.