When explaining the skin barrier and its importance to patients, more help is needed from the industry. For instance, a simple “Got Milk?”-type slogan that makes you immediately think of the skin barrier has not yet emerged. Physicians and scientists need a straightforward way to describe the skin barrier without getting too technical.
As described by Alice Prethima Michael, M.D., founder and managing medical aesthetic physician at Ageless Medi Spa (Kuala Lumpur, Malaysia), “The skin barrier, or stratum corneum, is the outermost layer of the skin, which provides critical defensive functions, including protection against all sorts of damage such as pathogens, major temperature changes, etc.”
In addition, the skin barrier is the first line of defense against the penetration of ultraviolet light, filtering much of it before it reaches deeper into the skin, which is where most of the pigment or ‘melanin granules’ reside,” she continued. “Melanin is, in fact, only a second line of defense against ultraviolet rays. Overall, any kind of disease condition will only worsen if the skin barrier is not maintained.”
On a deeper level, the skin barrier is composed of two different structural components, stated Nantapat Supapannachart, M.D., a cosmetic dermatologist in Bangkok, Thailand. “The corneocyte and inter-corneocyte lipids are arranged together with the cells providing structural support and acting as a hydrating reservoir for adequate enzyme processes,” she explained.
“The lipid bi-layer, a thin polar membrane made of two layers of lipid molecules, provides the boundary between the hydrophobic and hydrophilic interface, which regulates what goes into and comes out of the skin,” Dr. Supapannachart added. “Disturbing the function of this layer can have a significant effect on skin quality.”
According to Joel Schlessinger, M.D., a cosmetic surgeon and dermatologist who runs the Advanced Skin Research Center in Omaha, Neb., “The skin barrier is the difference between healthy skin and damaged skin. It is probably something that most dermatologists don’t think about at all. However, the reality is that the skin barrier is a very important concept to articulate to patients.”
Many people have been schooled to understand that the skin has seven layers," stated William Philip Werschler, M.D., F.A.A.D., F.A.A.C.S., a dermatologist and assistant clinical professor of medicine/dermatology, at the University of Washington School of Medicine in Spokane, Wash. “However, this really only refers to that millimeter or so of thickness of the epidermis,” he said.
“When we think of the skin, meaning we in the industry, what we are mostly thinking about mostly is the dermis and the collagen,” Dr. Werschler indicated.
The skin has several functions, and the first is the skin barrier, said dermatologist Carl R. Thornfeldt, M.D., the developer and founder of Episciences, Inc. (Boise, Idaho).
“This permeability barrier keeps the aqueous internal environment protected from the dry external environment, which includes all the toxins and contaminants in our environment,” he expressed.
Armed with an anatomical and technical understanding of the skin barrier, practitioners must then find a straightforward way to describe it to patients without getting too scientific. Dr. Werschler thinks physicians should consider how they might explain the skin barrier to a child. “I use a simple brick and mortar analogy,” he described. “The bricks are the skin cells and the mortar holding them together is the intercellular cement substance. At the bottom of the barrier you have the retaining wall foundation, otherwise the bricks would fall apart.”
Furthermore, there are specialized structures in the epidermis, Dr. Werschler continued.
“Imagine every ten bricks or so you place a decorative brick. Those are the melanocytes,” he said. “Your pigmentation is in the epidermis, and you are constantly shedding your pigmentation, as well. In addition, you can also have pigmentation after injury.”
Another visual way to explain the skin barrier is to conjur up the image of a shield, said Peter Lio, M.D., a clinical assistant professor of dermatology & pediatrics at Northwestern University Feinberg School of Medicine, and founding director of the Chicago Integrative Eczema Center (Chicago, Ill.).