Introduction: Chemical peeling involves the topical application of a wounding agent with the goal of effecting an organized regeneration of the skin. The histologic and ultrastructural features of actinic and age-related damage include structural abnormalities that disrupt normal epidermal and dermal architecture. The purpose of the present study is to evaluate the clinical and histologic effects of an enhanced medium-depth peel on photodamaged skin. We aimed to correlate the clinical and histologic findings with the ultrastructural changes occurring after the peel. These ultrastructural features are supposed to be more precise and informative than the clinical or histological response. They may also be employed as markers of peel response. Materials and Methods: In the present study, five patients with actinically damaged skin underwent enhanced medium-depth peels using 70% glycolic acid and 35% trichloracetic acid. Biopsy specimens were taken before the peel and 3 months after the peel for histologic and electron microscopic examination. Results: Clinical resolution of actinic damage corresponded with restoration of epidermal polarity. Characteristic histologic and ultrastructural features of the skin after peeling include markedly decreased epidermal intracytoplasmic vacuoles, decreased elastic fibers, increased activated fibroblasts, and organized parallel arrays of collagen fibrils. The diameters of individual fibrils are consistent with recent production of collagen by activated fibroblasts. Conclusion: Glycolic acid—tricholoro-acetic acid (GA-TCA) is an effective combination for a medium-depth peel in photodamaged skin both clinically and histologically. Electron microscopic studies following medium-depth peels reveal changes more profound than those seen histologically. The characteristic changes occurring in the keratinocytes, collagen, and elastic fibrils may be considered as guidelines or markers of the peel response.
A placebo-controlled, double-blind clinical trial to evaluate the efficacy of Imedeen® Time Perfection® for improving the appearance of photodamaged skin