TCA sản xuất bề mặt bong tróc khi được sử dụng trong những điểm mạnh từ 10% đến 30% [38]. Tại các điểm mạnh, TCA được chỉ định để điều trị rhytids tốt, thiệt hại tím, dyschromia biểu bì nhẹ, giảm keratoses bề mặt, vết sẹo, và hình thành comedone. Khoảng thời gian điều trị giữa các ứng dụng này tác nhân hóa học bề mặt bong tróc thường là trong vòng 7-28 ngày [7]. | Chemexfoliation and Superficial Skin Resurfacing Chapter 4 65 Trichloroacetic Acid 10-30 TCA produces superficial peeling when used in strengths from 10 to 30 38 . At these strengths TCA is indicated for the treatment of fine rhytids actinic damage mild epidermal dyschromia reduction of superficial keratoses scars and comedone formation. Treatment intervals between applications of this superficial chemical peeling agent are generally within 7-28 days 7 . As a general rule repeating the application before the erythema has faded from the previous treatment may enhance penetration of the successive application and produce deeper wounding 39 . TCA precipitates epidermal proteins and causes necrosis and exfoliation of normal and actinically damaged cells. TCA is nontoxic systemically and is neutralized by serum in superficial dermal blood vessels 19 . Partial epidermal exfoliation occurs with 20 TCA therefore a series of peels may be necessary in order to optimize the rejuvenating effects of papillary dermal remodeling 40 . Prior to starting the peel the face is cleansed degreased with alcohol- or acetone-soaked sponges. Then the TCA agent 10-30 is applied to the face with short gentle strokes using only light pressure. Proceeding clockwise or counterclockwise is according to preference but returning to an already painted area must occur before 2 min have passed to allow the acid to be neutralized before more solution is applied. One or two applications of TCA solution to the entire face produce a transient frost and mild erythema. The depth of penetration of the peeling solution is related to the number of coats applied. Protein precipitation results and leads to exfoliation without vesiculation. TCA is self-neutralizing and does not require water or bicarbonate to terminate the action of peeling. Patients experience a temporary burning and stinging sensations that can be relieved with cool compresses and cool air blown over the skin by an electric fan 41 . .
