A Damaged Skin Barrier. What Is It and How To Fix It.
A Damaged Skin Barrier. What is it and how to fix it.
Sabrina Schrope
Cosmetic Chemist, Owner of Vitamin You
What is the skin barrier?
Think of the outermost layer of the skin as a series of bricks lining a wall. Most of these bricks are called “keratinocytes” and are consistent in shape, size, and orientation.1 At the base of your brick wall, these cells are larger and tightly bonded but as they reach the outer layers they begin to thin and lose water content. The bricks are enriched with ceramides, free fatty acids, enzymes, and microflora to provide a protective barrier called the “epidermis”.1 In a healthy skin barrier, the cells can stretch and bend easily, have proper enzyme activity, retain more than 10% water, and protect against environmental risks.2
How does the skin barrier get damaged?
Damage can be assessed by the change in integrity of the barrier. Disruptions can be indicated by the rate of transepidermal water loss (TEWL), lipid composition, cell structure and function, and skin hydration.2 Environmental influences like UV radiation, temperature, air pollutants, water hardness, and external allergens act as irritants that trigger an inflammatory response and weakens the skin barrier.1 This why it’s often heard to “stay out of the sun”, “don’t cleanse with hot water”, “use soft water”, and “avoid products with fragrances”.
Allergens can vary for each person. Highly popularized allergens are fragrances and preservatives but can also be household allergens as well including dust mites, pet dander, and pollen.1
Moreover, the skin’s pH is healthy between 4 and 6. Skin with atopic dermatitis is often experienced in pH ranges closer to 7.1 Applying skincare products that are too acidic or basic can cause an imbalance in the pH. For reference, chemical exfoliants like AHAs and BHAs are around a pH of 3-4 and bar soaps are around a pH of 9-11.
New data also connects the lack in Vitamin D in patients with atopic dermatitis. Vitamin D production is primarily regulated in the skin from UVB sun exposure but can also be incorporated within the diet.1
While investigating the ways to make products more bioavailable or effective, the key method is to disrupt the skin barrier. Most companies know not to cause risk for the consumer, but instead opt for these mild disruptors for better active penetration: Solvents, Soaps, Humectants, Exfoliants, and Phospholipids.3 Most people argue, however, that these are necessary for a healthy skin barrier. In my opinion, when used in their regulatory limit, as directed, and not in excess, these are important for barrier regulation.
What does it mean to have a damaged skin barrier?
To have a damaged skin barrier means to not have efficient TEWL, microbial, physical, chemical, immunological, or neuro-sensory protection. Once the skin triggers a response to one of these deficiencies, the bi-products remain and interact with the skin in their own bioreactions. Like a cycle, these reactions do no go backwards but can be prevented.
For example, an increased pH will limit some enzymatic activity that rely on acidic conditions; specifically, antimicrobial capability. This disruption puts the person at higher risk of infections involving neutral-pH-loving bacterium like Staphylococcus. The lack of microbial diversity is usually associated with conditions like psoriasis, eczema, and atopic dermatitis. Other enzymes that function in acidity are lipid synthesizers which play an important role in our skin’s suppleness, water retention, and biochemistry.1
How to fix a damaged skin barrier.
Preventing triggers is the most important way to allow the skin to heal and repair as well as avoiding damage in the future. This includes wearing sunscreen and avoiding hot water, allergens, hard water, and pollutants. When using skincare products, always use as directed by the manufacture or doctor. In my opinion, avoid any products that emphasize the concentration of an active as these are usually too harsh for the barrier. Keep the routine simple and stop using products if they trigger redness or irritation.
Beyond this, studies show that the application of products with lipids can assist in the recovery of the barrier and prevent external triggers.2,1 Currently, there is debate on whether certain lipids are better than others. There isn’t an established lipid profile that will satisfy the microbial, biochemical, and hydrational influences of each person, especially due to the specificality that varies from each person. But there may be specific fatty acids to aid in each scope.
Finally, if the lack of vitamin D is the cause of skin barrier disruption, allowing less than 10 minutes of narrow-band ultraviolet B exposure may help and is used in the treatment of atopic dermatitis, vitiligo, and psoriasis.1
Citations:
1 Luger, T., Amagai, M., Dreno, B., Dagnelie, et al. (2021). Atopic dermatitis: Role of the skin barrier, environment, microbiome, and therapeutic agents. Journal of Dermatological Science, 102(3), 142–157. doi:10.1016/j.jdermsci.2021.04.007
10.1016/j.jdermsci.2021.04.007
2 Lodén, M. (2003). The skin barrier and use of moisturizers in atopic dermatitis. Clinics in Dermatology, 21(2), 145–157. doi:10.1016/s0738-081x(02)00373-5
3 Deckner G. (2019). “How to improve the bioavailability and efficacy of skin care actives” Prospector <https://knowledge.ulprospector.com/9837/pcc-how-to-improve-the-bioavailability-and-efficacy-of-skin-care-actives/>.