As the previous post inferred, using harsh cleansers on a regular basis will lead to dry skin. While that doesn’t sound TOO horrible, it does have further implications, which will be addressed in this post.
Dryness from Over-Cleansing and/or Using Harsh Cleansers
As stated before, dry skin is in essence the result of not having enough water in the stratum corneum (SC). The cause may be a enyzme deficiency or something else entirely, but water is the common denominator that affects everything. Could I be more generic…?
But anyways, skin dryness has two elements to it: what you see (visual) and what you feel (tactile and sensory).
Typically, flaky skin is the first sign of dryness. This is caused by the rapid swelling and shrinking that was discussed in the Short-Term Effects article. This constant cycle of gross bloating followed by swift desiccation increases the amount of individual corneocytes that have broken away from the lipid matrix, which of course can be compromised by surfactants. This loss in cohesiveness leads to flaky skin. If the condition worsen, the flaking will become more evident and lead to scaling, where cracks in the skin will appear. This is when the more tactile and sensory characteristics of dry skin become evident.
Tactile and Sensory Dryness–Scaling, Brittleness, and Cracking
As water becomes less and less able to remain in the SC, the skin will begin to feel rougher, more jagged, and may even rip from tensile force. The skin’s ability to repair itself will also become more comprised; the lag-time between the dip in water content from the initial cleanse (see picture) and when the skin is back to a more normal state, will continue to increase until the dehydrated state becomes longer than the normal state. This happens because the essential enzymes of the SC, such as those responsible for desquamation (exfoliation), depend on the presence of water in order to function. Lamellar granules may extrude them, but water activates them.
The Effects of pH on the Stratum Corneum
Thus far, I have not really mentioned the effect that pH has on the skin. This is because, while the pH of alkaline (true) soaps are damaging to the skin, when used occasionally, no negative side effects will manifest. This is because the SC has an inherent buffering system that is somewhat resistant to pH change; after all the SC has its own pH right?
The pH of the SC is regulated by the formation of free fatty acids from structures such as phosphilipids and ceramides, and the accumulation of hydrogen atoms from the sodium-proton pumps, among other mechanisms. So, its basically the lipid matrix of the SC that is responsible for its pH, right? And what did we learn in the previous post? We learned that surfactants reduce and leech away the lipids of the SC via solubilization and insertion/intercalation. If this happens only on occasion, the skin will retain its full capacity to repair itself. But if done on a regular basis, the “lag-time” will increase more and more, which will lead to a higher pH of the SC in general, since there’s less and less lipid content in the matrix.
And what will a higher pH of the skin on a more permanent basis allow for? Well for starters it will:
- Reduce the skin’s ability to exfoliate, which will lead to even MORE flaky skin, as demonstrated by the above-mentioned link;
- Increase the susceptibility of the skin to bacterial proliferation;
- And ultimately affect the LIVING layers of the epidermis that depend on the SC’s ability to inhibit both external exposure and internal water loss.
Increased Sensitivity, Erythema, and Pruritus
When the damage gets to this stage, the skin will respond with increased sensitivity… to everything. That includes cleansers, moisturizers, the SUN, and even artificial lighting. These responses manifest as erythema (redness) and/or pruritus (itchiness).
Redness typically occurs when some agent–including the surfactants themselves, penetrate down into the epidermis and dermis via insertion and elicit some sort of inflammatory response from the skin. Typically, the skin will generate cytokines as the inflammatory response, which can lead to increased free radical damage, and the like.
Itchiness is the body’s response to some foreign substance. Usually, the skin doesn’t have too many of these types of responses, since a healthy SC will keep most foreign objects from penetrating that deeply. That’s not to say that certain compounds like essential oils, fragrances, and preservatives don’t have a natural affinity to do so. However, a compromised SC will increase the rate and intensity of these reactions, which can be allergic and/or delayed hypersensitive types.
Worst of all is allowing some kind of viral, bacterial, fungal, etc… organism to penetrate from the skin into the body. I know, I know we’re getting into the realm of science fiction here because really, who’s going to let it get THAT bad? But given that the average person touches his/her face several hundred to even thousands of times a day, it’s a risk.
Will anyone allow things to get that bad? Probably not. And even using a “bad” cleanser with a mediocre moisturizer will significantly mitigate any damage. That being said, this IS the Ideal Skin Care Routine series. Stay tuned for the final part of the Cleansers series!