Your Skin Barrier Function
Your skin is made up of layers, each of which performs important functions in protecting your body. The outermost layer is called the stratum corneum, the skin barrier. A cosmetic formulator needs to understand the importance of the function of the skin barrier, and to develop products to support the barrier and not compromise it.
The skin barrier is crucial to life and the health of the skin and the body. Therefore, a healthy skin barrier keeps the skin balanced in moisture and lipids, protects us from dehydration, germs and so much more. The skin barrier, also called the stratum corneum, regulates moisture levels in the skin.
In this modern world, many people are experiencing a breakdown of the skin barrier and disruption of the natural process of skin.
This leads to dry skin and an opening for skin ailments; sensitive skin, wrinkles, eczema.
Some of the causes for disrupting the skin barrier are the environment, UV light, harsh skin care products, the foods and drinks consumed, medicines and disease.
One of the most important functions of the skin barrier is to protect it from transepidermal water loss (TEWL).
Transepidermal Water Loss (TEWL)
Transepidermal water loss measures the water loss from the skin, the stratum corneum. The skin loses water through the stratum corneum surface. Healthy skin barrier function, has lower TEWL and impaired barrier function skin has higher TEWL.
TEWL measurement is widely accepted and a standard method to evaluate the barrier function of the skin. TEWL instruments measure the water vapor flux in the air above the stratum corneum. It’s used for research of the hydration efficacy for skin care products, by dermatologists and pharmaceutical.
For skin care products, the skin care product is applied to the skin and measured to see how much water loss occurs.
How Skin Care Products Effect the Skin Barrier
Skin care products have the ability to support the skin barrier or compromise it. Irritating ingredients such as harsh surfactants and the pH of skin care products can compromise the skin barrier. This can be a cause for sensitive skin. Studies have shown that skin care products with a pH 8 decrease the skin surface pH and causes swelling of the stratum corneum and an increase in TEWL.
The application of skin care products high in pH may result in an unpleasant feeling of tightness on the skin and TEWL. This compromises the skin barrier and may cause ingredients in skin care products to irritate the skin and cause a reaction. The application of chemical exfoliants, microdermabrasion and aggressive scrubs stripping away our skin barrier
In conclusion, skin care products that support the skin barrier contain moisturizers, lipids and occlusives.
Other Factors that can Damage the Skin Barrier
- Chemical exposure
- Too much sun exposure
- Allergens or irritants
- Extreme weather, too dry or too humid
- Over cleansing
- Skin conditions
Signs of Skin Barrier Damage
- very dry skin
- inflamed skin or sensitive
- skin feels itchy
- rough, scaly patches
- bacterial, viral, or fungal skin conditions