Noninvasive Evaluation of Diameter and Density of Dermal Papillae in Psoriatic and Healthy Skin Using Reflectance Confocal Microscopy: An Intrapatient Controlled Study and a Review

Abstract

Reflectance confocal microscopy (RCM) is a noninvasive technique that allows a real-time, high-resolution imaging of the skin. It provides “en face” tissue sections of the epidermis and upper dermis at a cellular-level resolution close to conventional histopathology. Several studies have reported RCM findings in plaque psoriasis, along with their histopathologic correlation [González S et al., 1999; Lacarrubba F et al., 2018; Verzì AE et al., 2019; Guida S et al., 2022]. One of the main RCM features seen at the dermo-epidermal junction is the presence of enlarged dermal papillae (DP) containing dark, dilated canalicular structures, which histopathologically correspond to multiple capillary loops within the papillae [Verzì AE et al., 2019], and dermoscopically to uniformly distributed “red dots” [Lacarrubba F et a., 2015; Lacarrubba F et a., 2016; Wang ZY et al., 2022].