Today, I want to talk about the aging process of the skin. My goal is to provide the framework for understanding the role of various methods of reversing the impact of the aging process.

I am going to try to simplify things because patients are frequently confused by all the chemicals and modalities available on the market for facial rejuvenation.

Layers of the Skin: Key to Facial Rejuvenation

For our purpose, this skin is composed of three layers:

1. The Epidermis: The top layer (which means on top of the dermis and it is the one that blisters when a burn occurs)
2. The Dermis: The intermediate layer is the dermal layer (which is the equivalent to the leather)
3. The Fat Layer: This layer lies beneath the dermis

Each layer has a specific function. The epidermis prevents bacteria and dirt from penetrating the deeper layers, it also prevents fluid, proteins, and electrolytes from leaving the body. In general, the wound is considered healed when the epidermal layer is restored.

The Aging Process in the Epidermis

The aging process in the epidermis involves the accumulation of dead cells and changes in pigmentation. There are also some changes that I considered pre-malignant, but that has nothing to do with aging.

Aging in the Dermis and Loss of Collagen

With aging, the elastic fibers and collagen diminish in the skin. The role of the elastic fibers is to cause the skin to rebound when stretched to its pre-stretched state. So with loss of elasticity, the skin will hang.

Changes in the quality as well as well as the quantity of collagen occur with aging. A decrease in collagen, results in the thinning of the skin. Fine wrinkles as well as folds occur as a result of the weakness and lack of support. The change in collagen quality and quantity makes the skin more friable.

Methods for Facial Rejuvenation Treatment

Aging in the Epidermis: Exfoliation and Skin Pigment Treatments

As we age, since dead cells build up in the epidermis and changes in skin color (pigmentation) can occur, there are chemical products that consumers apply to clear away dead cells — these are called exfoliants. There are also mechanical modalities like microdermabrasion and peels that are usually applied by an esthetician that clear up the dead cells. There are different variations of physician-applied peels that penetrate the skin at different levels and, therefore, have varying results.

Aging in the Dermis: Collagen and Elasticity Treatments

There are very few modalities that will increase the elasticity in the skin and the only one I am aware of is a deep peel so-called Phenol peel, which is really a croton oil peel. It is a very drastic process that takes 2-3 weeks to heal with weeping and crusting. Because of the intense healing process, the industry has been trying to find alternatives. There is nothing of significance at this point in time that increases elastic fibers to a clinically significant degree.

Collagen Production

On the other hand, collagen production is more accessible for treatment because when the body heals the healing process involves collagen formation—whether the injury is chemical, thermal, or physical disruption. Therefore if we want to boost collagen we need to create a controlled injury. This leads us to several methods that can cause these controlled injuries:

• Chemical Peels: Croton oil peels, for instance, can stimulate collagen production as the skin heals, and can also improve elasticity a bit. Another common option is the TCA (trichloroacetic acid) peel, which can target the dermis and help encourage collagen formation.
• Micro-needling is a mechanical process. As the needle penetrates through the skin, it creates an injury to the dermis that will stimulate the production of a small amount of collagen. With multiple pinpricks to the skin, you will multiply collagen deposition, the attractive part of this process is that the epidermis is minimally traumatized and therefore the epithelialization process is very rapid (less than a day) and that is why healing occurs in 24 hours.
• Laser Treatments can also create controlled injuries to encourage collagen production. Early CO2 lasers took as long to heal similar to deep Phenol peel (2-3 weeks), so fractional lasers were developed. These make tiny holes in the skin down to the dermis instead of treating the whole piece of skin, similar to micro-needling, it limits damage to the epidermis while still boosting collagen.
• Radiofrequency (RF) is another treatment option that delivers energy into the skin through a probe applied under the dermis. This method targets the deeper layers of the skin with minimal impact on the top layer, making it a popular choice for those seeking non-invasive facial rejuvenation.

Connection Between Injury and Collagen Production

There is a connection between the amount of collagen the skin produces and the severity of the “injury” created by treatments. The more intense the injury, the more extensive the healing process, and the more collagen is formed but also, the higher risk of complications. When you hear about a treatment that heals in 24 hours instead of several days, it means the injury and therefore collagen boost is less.