Chemical peel

# Overview
A chemical peel is a body treatment technique used to improve and smooth the texture of the facial skin using a chemical solution that causes the skin to blister and eventually peel off. The regenerated skin is usually smoother and less wrinkled than the old skin.  Thus the term chemical peel is derived.  Some types of chemical peels can be purchased and administered without a medical license, however people are advised to seek professional help from a plastic surgeon or dermatologist on a specific type of chemical peel before a procedure is performed.

# Types
There are several types of chemical peels.

## Alpha hydroxy acid peels
Alpha hydroxy acids (AHAs) are naturally occurring organic carboxylic acids such as glycolic acid, a natural constituent of sugar cane juice and lactic acid, found in sour milk and tomato juice.  This is the mildest of the peel formulas and produces light peels for treatment of fine wrinkles, areas of dryness, uneven pigmentation and acne. Alpha hydroxy acids can also be mixed with a facial wash or cream in lesser concentrations as part of a daily skin-care regimen to improve the skin's texture.
AHA peels are used to:
- reduce fine wrinkling
- treat areas of dryness
- reduce uneven pigmentation
- aid in the control of acne
- smooth rough dry skin
- improve the texture of sun-damaged skin
AHA peels may:
- cause stinging
- cause skin redness
- cause mild skin irritation
- cause dryness
- take multiple treatments for desired results

## Beta hydroxy acid peels
It is becoming common for the use of Beta Hydroxy Acid(BHA) peels to be used instead of the stronger Alpha Hyroxy(AHA)peels due to BHA's albility to get deeper into the pore than AHA. Studies show that BHA peels control oil, acne as well as remove dead skin cells to a certain extent better than AHA's, due to AHA's only working on the surface of the skin.

## Jessner's peel
Jessner's peel is a combination of salicylic and lactic acids, and resorcinol. It is thought to break intracellular bridges between keratinocytes.

## Retinoic acid peel

## Trichloroacetic acid peels
Trichloroacetic acid (TCA) is used as an intermediate to deep peeling agent in concentrations ranging from 20-50%. Depth of penetration is increased as concentration increases, with 50% TCA penetrating into the reticular dermis. Concentrations higher than 35% are not recommended because of the high risk of scarring.
Trichloroacetic acid peels:
- are referred for darker-skinned patients over Phenol
- smooth out fine surface wrinkles
- remove superficial blemishes
- correct skin pigment problems
Trichloroacetic acid peels may:
- require pre-treatment with Retin-A or AHA creams
- require repeat treatment to maintain results
- require the use of sunblock for several months (this is a must)
- take several days to heal depending on the peel depth

## Phenol peels
Phenol is the strongest of the chemical solutions and produces a deep skin peel. Recent studies suggest that phenol is most likely only the carrier for another active component in the solution, namely croton oil. In fact, phenol alone produces only a light peel which is ineffective for restructuring the deeper dermal structures (such as wrinkles). The term Phenol/Croton oil peel has been proposed as a more accurate descriptor, but the established terminology phenol peel continues to be the dominant usage, as the role of croton oil in the mix is not as widely understood.
Effects of a phenol chemical peel are long lasting, and in some cases are still readily apparent up to 20 years following the procedure. Improvements in the patients skin can be quite dramatic.  A single treatment usually achieves the desired result.
Phenol peels are used to:
- correct blotches caused by sun exposure or aging
- smooth out coarse deep wrinkles
- remove precancerous growths
Phenol peels may:
- pose a risk for patients with heart problems
- permanently remove facial freckles
- cause permanent skin lightening by reducing the ability to produce pigment
- take several months to heal
- require increased protection from the sun for life

# Anesthesia
Light chemical peels like AHA and glycolic acid peels are usually done in dermatologists offices. There is minimal discomfort so usually no anesthetic is given because the patient feels only a slight stinging when the solution is applied. If a patient were to request something for pain, an oral pain pill like Tylenol with codeine would be appropriate.
Medium peels like TCA are also performed in the doctors office or in an ambulatory surgery center as an outpatient procedure and are a bit more painful. Frequently, the combination of a tranquilizer like Valium and a pain pill usually suffice.  TCA peels often do not require anesthesia because the solution itself has a numbing effect on the skin. The patient usually feels a warm or burning sensation.
Phenol is the classic deep chemical peel. The application is very painful and most practitioners will perform it under either general anesthesia, administered by an MD-anesthesiologist or nurse anesthetist. Less often, the procedure is done using very heavy sedation, usually intravenous or intramuscular. But that approach is less desirable for several reasons including possible adverse influences of the phenol upon the heart.

# References:
-  Demas PN, Bridenstine JB, Braun TW: Pharmacology of agents used in the management of patients having skin resurfacing. J Oral Maxillofac Surg 1997 Nov; 55(11): 1255-8.
-  Halaas YP: Medium depth peels. Facial Plas Surg Clin North Am 2004 Aug; 12(3):297-303
-  Resnick SS, Resnik Bl: Complications of chemical peeling. Dermatol Clin 1995 Apr; 13(2):309-12