Trichloroacetic acid is an analogue of acetic acid used for treating certain skin conditions. It is also an ingredient in chemical peels. It is keratolytic, which means it works by dissolving or breaking down the outer layer of the skin. It is available in liquid and crystal formulations, for use by your dermatologist.
While trichloroacetic acid can produce good benefit as a chemical peel, for certain conditions, it is also associated with a greater risk for pigmentary changes or very superficial scarring.
Trichloroacetic acid is an FDA pregnancy category C, which means there may be risk to the fetus, and so should only be used when it is clearly needed. It is not known if trichloroacetic acid is carried in breast milk, so caution is advised. Consult with your doctor before using.