First the skin is divided into two main layers, the epidermis and dermis. The epidermis is the outermost layer of the skin while the dermis is under the epidermis. The epidermis is the outer layer of skin. It is thinner than the epidermis; however, its thickness varies in different types of skin. It is thinnest on the eyelids at .05 mm and thickest on the palms and soles at 1.5 mm. The epidermis contains five layers, and in the bottom layer, the cells divide and push already formed cells into higher layers. As the cells move into the higher layers, they flatten and eventually die which the body gets rid of in the form of dead skin. The top layer of the epidermis, the stratum corneum, is made of dead, flat skin cells that shed about every two weeks. Essentially, skin is formed from the inside, pushed up to the surface, and eventually discarded.
When you get a chemical peel, a skincare professional applies a chemical exfoliant to the part of the body to be treated (Yes, chemical peels can be applied to parts of the body besides the face). Chemical exfoliants, also referred to as chemical peels, can consist of one primary ingredient like salicylic acid, glycolic acid, trichloroacetic acid, and lactic acid. On the other hand, peels can also include a mixture of chemicals. For example, a Jessner’s peel includes salicylic, lactic acid, and resorcinol. The type of chemical peel that you receive is a function of your specific skincare concern, your skin type, whether you have sun damage, and your overall skin health.
The purpose of the peel is to remove layers of the skin. In some cases, the chemical agent will affect the epidermis, either part or all of it, while in other cases, the chemical agent can remove skin down through the deepest portion of the dermis (called the reticular dermis). As seen below, the different types of peels go further into the skin.
- Superficial peels: as light as the stratum corneum (the outermost layer); however, it could go through all of the epidermis.
- Medium: All of the epidermis through to the papillary dermis (the upper part of the dermis).
- Deep: All of the epidermis down through the reticular dermis (the lower part of the dermis).
Now, back to what actually happens when a chemical peel is applied to the skin: the chemical that is applied to the skin causes the bonds of the skin to loosen and separate. The stronger the chemical agent, the deeper and faster the separation of the skin cells. The skin is undergoing a process called the desquamation process which can result in skin that looks slightly dry and flaky to skin that has large cracks and is coming off in sizable pieces. Essentially, the layers of the skin become dehydrated, shrink, crack, and slough off. It can look like slightly dry flaky skin; it can also look like large areas of cracking skin that come off in large pieces.