The skin barrier protects your body from harmful substances like irritants and germs. It’s often compared to a ‘brick and mortar’ system with lipids secreted by cells making up the ‘bricks’ and protein-rich corneocytes as the mortar. An inverse relationship between Transepidermal water loss (TEWL) and subcutaneous (SC) hydration is seen when the barrier is disrupted. Barrier abnormalities are found in many diseases, including irritant contact dermatitis, allergic contact dermatitis, burns, ulcers, and lamellar ichthyosis. Exogenous or endogenous processes trigger barrier disruption.
Protects the Skin
The skin’s outermost layer, the stratum corneum, resembles a brick wall under a microscope. It is composed of hardy skin cells (corneocytes) tightly bound together by mortar-like fats, including ceramides, cholesterol, and fatty acids, as well as an essential protein called filaggrin, which helps make natural moisturizing factors. This fabulously thin brick wall keeps you alive by preventing harmful environmental toxins, bacteria, allergens, and other pathogens from penetrating the epidermis. It also keeps water from escaping and evaporating, leaving your skin feeling dry. When the skin barrier function is disrupted or depleted by harsh products, extreme environmental conditions, and excessive cleansing with soap and hot water, our skin becomes irritated, dry, and more permeable to the outside world. This can result in inflammatory conditions like dermatitis, psoriasis, and ichthyosis vulgaris. While maintaining a robust skincare routine with gentle cleansers and nourishing moisturizers is essential, incorporating the use of the best facial tools can further enhance your skin’s resilience. These skincare tools can play a pivotal role in promoting optimal skin health by aiding in the absorption of nutrients and active ingredients, contributing to the overall well-being of your skin. When the barrier is intact, a lipid matrix forms around each corneocyte within the cornified cell envelope, acting as a protective shield. The lipid matrix allows good things like nutrients and active ingredients to pass through easily. It is held in place by tight, gap, and adheren junction proteins.
Maintains Moisture
As the outermost layer of skin, your moisture barrier must function well to keep hydration and irritants out. If the barrier is compromised by inflammation, a loss of lipids, or other factors, it won’t be as sturdy. This makes the skin more susceptible to letting in external interlopers and can cause a chain reaction that leads to irritation or even redness. Your skin barrier locks out destructive pathogens, allergens, pollution, and free radicals while maintaining hydration. It’s a complex system of two top levels of the epidermis: the lower level, known as the stratum corneum (think brick wall), and the upper level, called the mantel. The mantel is a thin, slightly acidic natural sebum and sweat coating. At the same time, the stratum corneum is built out of 15 to 20 layers of dead skin cells, organized into a brick-and-mortar pattern with a lipid matrix of ceramides, cholesterol, and free fatty acids, including squalane. While many things can contribute to weakening the barrier, including stress, environmental pollutants, and some topical products, repairing it is possible with the proper skincare routine. Look for skincare formulas designed with barrier strength, including ingredients like squalane, cholesterol, niacinamide, and green tea polyphenols. This will help repair the barrier and make it more resilient to damage.
Prevents Irritation
When the barrier functions appropriately, it prevents excessive water loss from the skin in one direction (inside-outside barrier). It keeps harmful substances in the outer layer of the epidermis from entering the inner layer (outside-inside barrier). It also protects against irritation. If you want to keep your barrier functioning optimally, try not to use products known to disrupt it. For example, chemical exfoliants that use acids and granules to remove dead skin cells can cause the barrier to break down. And the same goes for harsh physical exfoliators that use rough textures, abrasives, or scrubbing particles. In diseases with disrupted barrier function, like psoriasis, eczema, and dermatitis, the proteins that form the junction between keratinocytes and the surrounding epidermis, such as desmogleins and E-cadherin, are altered. This may lead to the loosening of the barrier and a subsequent increase in TEWL and sensitivity to external irritants. To help strengthen the skin barrier, consider using moisturizers with ceramides and other ingredients that mimic them, such as jojoba oil. You should also prioritize products with natural plant oils that can naturally hydrate the skin, such as squalane and urea. And be sure to avoid products with fragrances, essential oils, and sulfates, as these can irritate and damage the barrier over time. This is particularly true if you have a sensitive skin type.
Prevents Ageing
The skin barrier is an essential part of healthy skin because it prevents irritants, allergens, and pollutants from getting into the deeper layers of the skin, which could cause infection. This also keeps the skin hydrated and prevents wrinkles. The stratum corneum’s protective layer is structured like a brick wall. The walls comprise skin cells (corneocytes) held together with mortar, a lipid membrane made from cholesterol and ceramides. When this barrier is disrupted, the skin becomes more porous and susceptible to damage from environmental factors and harsh products. The signs of a compromised barrier are dryness, flakiness, and redness. If the barrier is permanently damaged, it can lead to various conditions, including psoriasis, eczema, atopic dermatitis, and hives. Diseases that affect the whole epidermis and cause a large area of severe burning are usually life-threatening, such as staphylococcal scalded skin syndrome, pemphigus vulgaris, and toxic epidermal necrolysis (Lyell syndrome). Maintaining your skin’s barrier function is an easy step you can take to protect against aging. A good skincare routine that includes a gentle cleanser, a nourishing serum, and a rich moisturizer is the best way to keep your barrier healthy and strong. Look for ingredients like hyaluronic acid, which hydrates and helps skin retain moisture, and encapsulated retinaldehyde (the best Vitamin A) to help stimulate collagen production.
