Trichloroacetic acid and bichloroacetic acid — Both trichloroacetic acid (TCA) and bichloroacetic acid (BCA) are caustic acids that destroy the wart tissue via chemical coagulation of tissue proteins. TCA is used most commonly, and must be applied by a health care provider. It can be used on the cervix and vagina, and during pregnancy.

An 80 to 90 percent TCA solution is applied sparingly to the wart tissue with a cotton swab; the wart turns white as the solution dries. Application of an ointment or gel (such as petroleum or lidocaine jelly) to the normal tissue surrounding the wart can help prevent spreading of acid to unaffected areas. Excessive application of medication can be neutralized by washing with soap or sodium bicarbonate solution, otherwise the patient may experience pain or burning of adjacent healthy tissue.

Repeated weekly application is required for four to six weeks, or until the lesions have cleared. Thick, large lesions may not respond because the acid may not penetrate to treat the entire lesion.