What is trichloroacetic acid? What's the use? thank you

Hello: trichloroacetic acid: trichloroacetic acid is a strong acid, which can be used to burn warts and is generally used to treat type II lesions. Before smearing, dip a cotton ball in 2% caine and smear the affected area for 3-5 minutes, then dip a cotton swab in 50% trichloroacetic acid to make the liquid medicine reach the base; Be careful not to hurt the surrounding healthy mucosal tissue when taking the medicine, and do not use it during menstruation; Use it twice a week. Or use 20% salicylic acid glacial acetic acid for external application.