Chemical peeling is used to improve the skin’s appearance by applying a chemical solution to the skin, causing the top layers of skin to separate and peel off. The new skin is smoother, less wrinkled, more even in color, peels can also be used to improve acne. Chemical peels can be performed at different depths, depending on the layer of correction desired. Deeper peels will cause the skin to peel for a longer period of time and provide more improvements in the skin. There are also a variety of acids and peeling agents that can be used alone or together, depending on skin conditions to be treated.
Chemical exfoliation and peels involve using destructive chemical agents to create a controlled wound. All peels (whether they are chemical or laser) create a mild burn. They improve skin by the wound healing process, new tissue is created and damaged tissue is quickly replaced. Chemical peels stimulate the fibroblasts wound healing activity, the proliferation of fibroblast activity increases collagen and elastin. The depth of the wound determines the amount and intensity of healing. The body’s response to the burn is what yields the results, a deeper peel will result in more correction.
The terms exfoliation and chemical peel are often used interchangeably, however superficial peels are technically exfoliation not a true peel. True chemical peels penetrate into the papillary dermis.
Chemical exfoliation and peels are a way to speed up the natural migration process of skin cells. When the bonds between cells are dissolved and epidermal cells begin to shed more rapidly. The shedding skin cells send signals for more cell division, which in turn forces keratinocytes to the top of the stratum corneum. This process helps treat acne, fade skin discoloration and leave the skin with a fresh new layer of skin on the surface.
With chemical peels, the depth is determined by the agent used, concentration of agent, and time applied.
Acids and Chemical Peeling Agents
Chemical peels use several types of acid solutions to improve and smooth the texture of skin. Acids come in different strengths and can be used individually, combined or layered. A variety of acid compounds can be used. There are many branded peels, however an experienced esthetician can also create custom peels.
AHA (alpha hydroxy acid), AHA’s are water soluable. Glycolic acid is formulated from sugar cane, and has the smallest AHA molecule, giving it great penetration ability and softening ability. Glycolic acid works by loosening up the horny layer and exfoliating the superficial top layer, also stimulates collagen growth.
AHA, derived from sour milk and bilberries, mild action, often used in conjunction with other acids.
AHA, derived from apples, mildly invasive peel. It can open up the pores, allow the pores to expel their sebum and reduce acne.
AHA, derived from grapes, mildly invasive, similar benefits to other AHA’s
BHA (beta hydroxy acid) differs from AHA’s, because it is oil soluble and penetrates the lipid plug in a congested follicle. Salicylic acid is also less irritating than glycolic acid and doesn’t alter skin barrier properties. Has antimicrobial properties.
Derived from retinoids; which is denatured vitamin A. It is chemically similar to Retin-A and is used to remove scars as well as wrinkles and pigmentation problems. It is usually performed in conjunction with other acids to a cause peeling at a deeper level.
A dihydroxy phenol produced from resins. Used externally resorcinol is an antiseptic and disinfectant, and is used in ointments in the treatment of chronic skin diseases such as psoriasis, and eczema. Resorcinol has been used as a peeling agent as far back as 1800 in strengths up to 30%, the problem with high concentrations of resorcinol is it’s corrosive ability and tenancy to depigment. Currently it is used at low concentrations in chemical peel compounds such as Jessner’s Peels.
TCA (Trichloroacetic acid)
TCA is a chemical cauterant, an agent that coagulates skin proteins. TCA can be used in different strengths and has the ability to penetrate past the papillary dermis and should be used with caution. TCA in concentrations less than 25% can be used in superficial peels. Medium depth peels are achieved with 30-40% TCA, and 50% TCA should only be used by a physician to achieve a deep peel and has greater chance for complication. TCA is used in the Obagi Blu Peels.
Phenol is a very strong and toxic chemical, phenol peels require general anesthetic and heart monitoring. Lasers and TCA have largely replaced deep phenol peels, however low concentrations are often added to superficial and medium depth peels.