Applications of reflectance confocal microscopy in photoaging and aesthetic conditions: skin characterization and treatment monitoring.

Reflectance confocal microscopy (RCM) is an in-vivo, non-invasive imaging modality that provides a high-resolution image of the epidermis and upper dermis. RCM has been utilized as a diagnostic aid for several inflammatory, infectious, and malignant skin conditions; however, its use for clinical and aesthetic skin purposes has not been well established. The purpose of this review is to describe the landscape of RCM utilization for the application of aesthetic skin conditions. A comprehensive literature search was conducted using PubMed using the search terms "reflectance confocal microscopy cosmetic", and "reflectance confocal microscopy aesthetic". The search was limited to clinical and animal studies published in English in the last 10 years. RCM must have been utilized to measure an aesthetic dermatological outcome to be eligible for the review. After data abstraction, a total of 46 studies that met the inclusion criteria were identified. The most common utilization of RCM for cosmetic conditions included treatment monitoring and skin morphologic characterization. The primary skin conditions evaluated included skin aging, pigmentation, skin dryness, irritated, and sensitive skin related conditions. Treatment monitoring was primarily conducted for topical agents for skin hydration, skin UV protection, acne, skin dryness, and skin pigmentation purposes. Identification of histo-structural correlations with aesthetic skin conditions may pave the way for future aesthetic drug development. As the popularity of cosmetic dermatologic procedures continues to increase, utilization of RCM for skin characterization and treatment monitoring may be beneficial.