There are some effective methods for removing layers of skin to improve aging face and dermatologic defects : chemabrasion (chemical peeling), dermabrasion(surgical removal), laserabrasion. Chemabrasion, generally performed with a chemical solution, is most useful for removal of fine facial wrinkles and abnormal pigmentation. The application of chemical caustics, especially TCA (trichloroacetic acid), is known to be an effective and is now commonly practiced to improve the surface of the facial skin that has been blemished by pigmentation, wrinkles, solar damage and certain scars. Trichloroacetic acid is a colorless melting crystal and derivatives of acetic acid which has protein precipitating properties. It has specific odor but there is not systemic toxic effect like a phenol. It has heavy caustic effect on skin and mucosa and cause the coagulation necrosis of the skin and therefore, it must be handled carefully and stored in the proper condition. Especially, moderate to high concentrated TCA solution must be treated by well-trained persons.
  A 46-year-old woman visited a private clinic for removal of fine wrinkles around the lip. She was refered to our department because of acute upper lip coagulation necrosis which was caused by injection of 35% TCA solution mistaken for lidocaine, which was supposed to be used for anesthesia. At her arrival, cental half of upper lip showed severe coagulation necrosis. The lesion was well discriminated in a few days, then debridement and immediate reconstruction was done using an Abbe flap.
  Chemical peeling is a relatively effective procedure for improvement of aging skin lesion in a lower cost with a short time operation, if the practitioner has much experience and optimal indication is properly selected. But not so as, side effect and complication may be often ocurred in a mistake and as a result irreversible scars are remained. We experienced a rare case of upper lip necrosis which was caused by TCA injection mistaked for lidocaine in a private clinic and so, we report this case with the results of experiment of rabbit model which was observation of macroscopic and microscopic changes of the abdominal skin of the rabbit injected with serially diluted TCA solution.