Glycolic acid treatment increases type I collagen mRNA and hyaluronic acidcontent of human skin

BACKGROUND. Chronic solar irradiation results in both morphologic and funct ional changes in affected skin. alpha -hydroxy acids, such as glycolic acid , have been shown to improve protodamaged skin. OBJECTIVE. To investigate alterations in collagen gene induction and epider mal and dermal hyaluronic acid production as a result of administered glyco lic acid. METHODS. In this study we compared collagen gene expression from skin biops y specimens, and epidermal and dermal hyaluronic acid immunohistochemical s taining between glycolic acid-treated and vehicle-treated skin, Forearm ski n was treated with 20% glycolic acid lotion or a lotion vehicle control twi ce a day for 3 months. RESULTS. Epidermal and dermal hyaluronic acid and collagen gene expression were all increased in glycolic acid-treated skin as compared to vehicle-tre ated controls. CONCLUSION. Our data suggest that epidermal and dermal remodeling of the ex tracellular matrix results from glycolic acid treatment. Longer treatment i ntervals may result in collagen deposition as suggested by the measured inc rease in mRNA.