A clinical and histologic evaluation of two medium-depth peels - Glycolic acid versus Jessner's trichloroacetic acid

BACKGROUND. Chemical peels using alpha hydroxy acids have become one of the most frequently requested dermatologic procedures. The use of glycolic acid in superficial chemical peels is now well established. However, the role of glycolic acid in medium-depth chemical peels has yet to be elucidated. OBJECTIVE. We performed a clinical and histologic comparison of 70% glycolic acid versus Jessner's solution as part of a medium-depth chemical peel using 35% trichloroacetic acid (TCA). METHODS. Thirteen patients with actinic keratoses, solar lentigines, and fine wrinkling were evaluated prospectively. Each patient was treated with 70% glycolic acid plus 35% TCA (GA-TCA) to the right face and Jessner's solution plus 35% TCA (JS-TCA) to the left face. Clinical and histologic changes were evaluated at 7, 30, and 60 days postoperatively. RESULTS. Clinically, the GA-TCA peel was effective in treating photodamaged skin. The GA-TCA peel was slightly more efficacious in removing actinic keratoses (clinical response score = 1.5) than the JS-TCA peel (clinical response score = 1.0). Histologically, the GA-TCA peel caused the formation of a slightly thicker Grenz zone (mean = 0.053 mm) 60 days postpeel than the JS-TCA peel (mean = 0.048 mm) (not statistically significant). The GA-TCA peel caused more neoelastogenesis than the IS-TCA peel, while the JS-TCA peel resulted in move papillary dermal fibrosis and neovascularization than the GA-TCA peel. CONCLUSION. The GA-TCA peel is a new medium-depth chemical peel that is effective in treating photodamaged skin.