Can exfoliation damage the skin?

The short answer to that is yes. This is particularly true as you grow older. This was recently brought to my attention by "my London Correspondent" who will remain anon. until she gives me permission to use her first name.

As many of you understand, as we age, the ability of the skin to produce and repair collagen and elastin is impaired: a double whammy when you consider that intrinsic and extrinsic damage in the forms of UV light and sugars are also nibbling away at our skin structure day after day, year after year. So, being smart, and considering all the lasers that cause deliberate damage to the skin in order to increase collagen production, we exfoliate the epidermis to trigger thickening of the dermis. (This is also the modus operandi of Retin A.) The actual thickening of the dermis is caused by the process of inflammation, which is never a good thing for any part of the body.

So are we going too far?

The skin is composed of the epidemis and dermis, and underlying fat layers. Although the epidermis varies in thickness over different parts of the body, being thickest on the soles of the feet and thinnest on the eyelids, it consists of five distinct layers, which all have an important role to play. These layers from top to bottom are the stratum corneum or horny outer layer, the stratum licidum, stratum granulosum, stratum spinosum and stratum basale.

Forgive me if this is a little too much "Skin 101" for you, but it is important to remember when you are exfoliating every day as I have been doing.

If you look at the diagram, you will see that the cells in the basal layer of the skin are a different shape from those at the top. They appear column-shaped. These cells are alive and have nuclei.

As these cells reproduce, they push those before them upwards through the other layers of skin, flattening out as they do so. During this process, they also die, eventually arriving at the stratum corneum as dead tissue. Here they remain for a couple of weeks or so before naturally sloughing off. (People who have psoriasis have basal cells that reproduce a little too rapidly, causing the epidermis to thicken and appear silvery.) Close to half the cells produced in the basal layer remain to generate daughter cells.

When the cells reach the next layer, the stratum spinosum or "prickly layer," they begin to produce keratin. Keratin is important as it helps the skin perform one of its vital functions: keeping moisture in the body and also keeping moisture out, so that we don't bloat up like soggy balloons in the shower for example. Although I have never seen this written anywhere, I suspect that the horny layer also exerts some pressure on, or provides outer support for the aging dermis, helping to prevent sagging and wrinkling.

The next layer of the epidermis, the stratum granulosum or "granular layer," is also very important to the structure of the epidermis. In this layer, the keratin proteins and water-proofing lipids (fats) are produced and organized to better keep the moisture barrier intact and functioning well. For reason unknown, French skin scientists and product formulators appear to pay far more respect to the well-being of these lower layers than their western counterparts.

The fourth layer of the epidermis, which is just underneath the horny outer layer, is the stratum lucidum or "clear layer." It isn't present all over the body, at least not in any appreciable thickness. It is thickest on the soles and palms and serves as an additional barrier between the stratum granulosum and the stratum corneum. This is significant because it means that in most areas of the body, including the face, neck and décolletage, the very important stratum granulosum is right underneath the stratum corneum.

The outer layer of dead cells that we see and feel is the stratum corneum and nature covered us in it for a very good reason. It keeps out pathogens, further protects the skin from moisture loss by actually absorbing water, and provides some (though not enough) protection from the sun.

Removing this outer layer by constantly exfoliating (either by physical means such as ground fruit pits or chemical means such as alpha-hydroxy acids) also disrupts the important barrier function provided by lipid lamellae (ceramides, cholesterol and free fatty acids) in the lower stratum corneum and stratum granulosum.

However, the outermost layer is normally between 15 and 20 cell layers thick. Considering most of us use moisturizer and sunscreen, this thickness isn't always necessary. That said, it doesn't require exfoliating every single day in order to remove the outermost layer of cells that make the skin appear dull and often flaky. Once (at most twice) a week is sufficient. Daily exfoliation is fine for adolescents and people in their 20s, whose basal skin layers are turning over cells more efficiently, but not such a good idea when the skin is spending longer renewing itself.

As my London Correspondent pointed out, the "uglies" she (and many women) experience after aggressive skin treatments seem to be associated with the removal of the epidermal layer in order to generate growth and repair in the dermis. The uglies often involve sagging and temporary wrinkling, possibly due to the decimation of the outer support layers. (Although no one actually tells you this...) In the case of younger people, whose dermis is strong and well-supported, and whose epidermis turns over more quickly, daily exfoliation is beneficial.

My London Correspondent referred me to a paper by Desmond Fernandes, MB, BCh, FRCS(Edin), a plastic and reconstructive surgeon practising in Cape Town, entitled Minimally Invasive Percutaneous Collagen Induction. It is a fascinating read about the use of a dermarolling technique. In part, Dr. Fernandes asks,

Why destroy the epidermis to make the skin smoother? The epidermis is an extremely complex, highly specialized organ. It may be only 0.2 mm thick but it is our sole protection from the environment. We should never damage the epidermis unless the risk of leaving the epidermis intact is greater than the risk of removing it. Wrinkles are hardly a good excuse to destroy this wonderfully complex interface that we have with the world. Whatever we do, we should try to ensure that the basic normal architecture of the skin is never altered. To rejuvenate facial skin and really look young, we need a perfect epidermis with natural dermal papillae, good hydration, normal color, and normal resilience.

Dr. Fernandes briefly discusses the introduction and use of lasers and their effects on dermal and epidermal tissue. I thought this was most interesting:

Smoothing skin is still most effectively done by CO2 laser through the aggressive heat damage that is caused. No other technique can match it, but at the same time, CO2 laser causes the most complications. A significant problem is that deep treatments like this stimulate fibrosis rather than new, naturally oriented collagen formation. This fibrosis may result in a much whiter reflectance from the dermis, giving the skin an unnatural pallor. The sad fact is that several years after the treatment, the collagen will be resorbed—as all scar collagen is—and fine wrinkles will start to show as a result of the thin epidermis with no dermal papillae. The impaired hydration of the skin means that it is not as plump as it could be and can look atrophic due to this excessive destruction.


Better ways to encourage growth in the dermis

Better ways to thicken the dermis include the ingestion of L-carnosine and use of a skin cream containing L-carnosine. (You can add L-carnosine powder to your favorite skincare preparation as well.) L-carnosine can be purchased online through SkinActives. IPL therapy also increases dermal thickness but comes with some risk as some women have experienced pitting and divoting after being treated with the high energy lamps in their dermatologist's office. Amber light home treatment wands are safer, but the jury's still out on whether or not they actually work effectively. (If you use an amber light wand such as the Anti-aging Lightstim, be sure to use an antioxidant cream before hand to prevent free radical damage. Green tea creams or a light spraying with green tea before use is recommended.)

Fractional lasers can help firm the dermis and deal with superficial, mild wrinkling and appear to have fewer incidences of damage than radiofrequency devices such as Thermage. I prefer to think of fractional laser treatments as preventive though, and only if you really can afford them. They work by creating channels of damage for the body to repair, which is far less risky than deliberately damaging the entire dermis.

Many women swear by the use of vacuum devices such as the Vaculifter, available from NCN Professional Skincare. (Nanci over there is very helpful so ask away...) These work by stressing the dermis and causing it to "defend" itself by thickening. Then there are dermarollers, which pierce the skin with fine needles, causing the dermis to similarly react and thicken. (It is important to use a dermaroller correctly, and penetration should be deep. The procedure should not be carried out superficially several times a month, but deeply and less often, so that the skin is not in a perpetual state of inflammation and has time to heal. For an interesting discussion on this, please visit the EDS forum thread on dermarolling and look for the entries by "Bethany" who is a deep dermaroller and is extremely informed on the topic.)

The good thing about all these methods is that they encourage the formation of new collagen while keeping the epidermis intact as nature intended.