WHAT ARE PEELS?HOW ARE THEY USEFUL?

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 dead skin to slough off and eventually peel off. The regenerated skin is usually smoother and less wrinkled than the old skinThere 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.
There are five main fruit acids: citric acids (citrus-derived), glycolic (derived from sugar cane), lactic acid (although derived from milk, this is still considered a "fruit acid"), malic (derived from apples) and tartaric (derived from grapes)

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 beta hydroxy acid (BHA) peels to be used instead of the stronger alpha hydroxy acid (AHA) peels due to BHA's ability to get deeper into the pore than AHA. BHA peels control oil, acne as well as remove dead skin cells to a certain extent better than AHAs due to AHAs only working on the surface of the skin.
Salicylic acid (from the Latin Salix meaning: willow tree) is a biosynthesized, organic, beta hydroxy acid that is often used.

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.
Trichloroacetic acid peels:
are preferred 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

These are the common peels used in the dermatology practice.There are also other peels like phenol peels,Retinol peels,Jessners' peels which are less commonly used.