chemical peel

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The removal of skin blemishes or wrinkles by applying a caustic chemical, such as an acid, that produces a mild, superficial burn.
• noun Any of various treatments used in such removal.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun the application of a mild caustic substance to the skin in order to remove blemishes