The stratum corneum (SC), the skin's outermost layer and interface with the outside world is now well recognized as the barrier that prevents unwanted materials from entering, and excessive loss of water from exiting the body. The structure of the SC is outlined as well as techniques to visualize the barrier. The lipid organization and ionic gradients, as well as the metabolic responses and underlying cellular signalling that lead to barrier repair and homeostasis (Skin functions in homeostasis include protection, regulation of body temperature, sensory reception, water balance, synthesis of vitamins and hormones, and absorption of materials). The stratum corneum (SC), is a vital front-line, protecting us against the perils of the environment; UV, pollution, infection, toxic chemicals and so on.
The skin barrier consists of cells and lipids (fats). Also known as the permeability barrier, moisture barrier, or lipid barrier, the skin barrier is responsible for making sure essential water and electrolytes don’t evaporate from skin. It also serves as a protective shield against harmful microorganisms by producing antimicrobial peptides and proteins. On top of that, the skin barrier helps sustain skin’s immunity, and it regulates inflammation.
Weakened Skin Barrier
When the skin barrier is healthy, your complexion appears smooth, clear, even-toned, and balanced. On the flip side,if your skin barrier is damaged, then that’s when you’ll experience redness, irritation, breakouts, rashes, burning sensations, broken capillaries, dryness, tightness, and other symptoms.
The skin has its own flora (also commonly referred to as skin microbiota) the natural levels of bacteria which work with the oils and natural humectants of your skin to keep the barrier strong from the outside environment and to keep it at the ideal “potential hydrogen” (pH) level is around 5.5, the outer layer of the skin needs to be slightly acidic to maintain skin-barrier function and ward off infection and toxins. When skin is too alkaline, it feels dry and sensitive, and may even age faster. AND, as our skin ages, the skin pH protection weakens, it’s unable to maintain acidity, as we get older and older our skin pH become less and less acidic and close to neutral (pH 7), that may result in painful, inflamed skin. A study in the British Journal of Dermatology that tracked women's skin over an eight-year period found that women with an alkaline stratum corneum had more fine lines and crow's feet — and were more prone to sun damage — than those with acidic skin. When harsh products such as alkaline or harsh acidic cleansers, toner, or antihistamine cream prescribed are used, extreme temperatures (like from hot water) or certain medications are taken, the pH balance of skin can be disrupted—the natural bacteria can shift so that good bacteria decreases and bad bacteria flourishes, and it’s the weakness of this shield that is the underlying cause of inflamed skin.
The steroid creams that are often prescribed for severe irritations, eczema and allergic reactions cause a thinning of the skin which, while reducing the inflammation, leave you vulnerable to further irritants. A weak or damaged skin barrier allows irritants in, or irritates more easily and is more inflamed.
Damaged skin barrier causes
Unfortunately, the skin barrier is very fragile and vulnerable to damage. As we age, the lipids within our skin decrease (especially after the age of 40). This causes the skin to become prone to dryness, flakiness, wrinkling and sagging. These lipids can also be depleted by any of the following.
The top triggers are:
Emotional Stress. Mental stress caused by life experiences, such as work problems, family issues, etc.
Physical Stress. Fatigue, dehydration, malnourishment, etc.
Environmental Stress. Climate/weather changes, indoor overheating or over-cooling, or toxins in the air or water.
Smoking. This dehydrates the skin and slows down collagen production and cell metabolism.
Pollution. Smog, chemicals in work environments, fumes from carpets and furniture, etc.
Harsh products. Harsh skin cleansers containing sulfates, artificial fragrances, colorants, SD alcohol, and preservatives are known to trigger skin sensitivity, other products include solvents, detergents, and irritating chemicals. Excessive use of perfumes can even weaken the barrier.
Alkaline skincare products.
Cosmetic procedures. Laser resurfacing and other methods used to remove the top layer of skin can damage the skin barrier if not used proper skincare after treatment.
Sun damage. Without protecting skin from UV rays, skin can become sensitized.
Nutrition. A generally poor diet can manifest on skin, but low-fat diets and spicy foods have been linked to weakening the skin barrier.
Over-exfoliation. Scrubs and mechanical exfoliation (harsh brushes, gloves etc.) entirely as they cause micro-trauma to the surface of the skin and can strip the skin of its barrier – we don’t want ANY KIND OF SCRUB. However, even when it comes to skin-friendly acid-based exfoliation, you need to be careful not to go bananas on it. Keep the exfoliation Gel or Mask to once every two-three days, depending on what is advised for your specific skin. If your barrier is truly compromised, lay off exfoliation entirely for a few weeks at least.
Age. As you get older, your skin barrier function naturally weakens.
Restoring skin barrier
The barrier function is an extremely important concept in skin care. It describes the strength of the skin barrier and how well it protects skin from the external environment. Like the acid mantle on the surface of skin (a physical and chemical barrier that keeps out microorganisms and irritants), the barrier function serves a crucial protective function for the skin. "If your skin barrier is working well, it will retain water effectively, maintaining good hydration balance, and be resilient yet flexible. This means it contains the right amount of lipids, and the right amount of Natural skin identical Moisturising Factor. At Sunsara we have the right treatment and products to help to restore your skin healthy barrier function. Visit our page of treatments HERE.
*** Essential Fatty Acids and Skin Health. Linus Pauling Institute. 2017. Accessed January 30, 2017.
*** MJ CHI M. Role of ceramides in barrier function of healthy and diseased skin. – PubMed – NCBI. Ncbinlmnihgov. 2005. Accessed January 30, 2017.
*** GL G. Physiologic changes in older skin. – PubMed – NCBI. Ncbinlmnihgov. 1989. Accessed January 30, 2017.
*** Howard D, King A. CODE RED: Coping Strategies for Sensitized Skin. Dermalinstitutecom. Accessed January 30, 2017.
*** Loden MWessman W. The influence of a cream containing 20% glycerin and its vehicle on skin barrier properties. International Journal of Cosmetic Science. 2001;23(2):115- 119. doi:10.1046/j.1467-2494.2001.00060.x.
*** Lee S, Jeong S, Ahn S. An Update of the Defensive Barrier Function of Skin. Yonsei Medical Journal. 2006;47(3):293. doi:10.3349/ymj.2006.47.3.293.