Dermoscopy, confocal microscopy and optical coherence tomography features of main inflammatory and autoimmune skin diseases: A systematic review

Background/Objectives: Non-invasive skin imaging features of main skin inflammatory and autoimmune diseases have been reported, although a comprehensive review of their correlation with histopathologic features is currently lacking. Therefore, the aim of this paper was to review the correlation of dermoscopic, reflectance confocal microscopy (RCM) and optical coherence tomography (OCT) criteria of main inflammatory and autoimmune skin diseases with their corresponding histopathologic criteria correlation. Methods: Studies on human subjects affected by main inflammatory and autoimmune diseases, defining the correlation of dermoscopic, RCM or OCT with histopathologic criteria, were included in the review. Five groups of diseases were identified and described: psoriasiform, spongiotic and interface dermatitis, bullous diseases and scleroderma. Results: Psoriasiform dermatitis was typified by white scales, corresponding to hyperkeratosis, and vessels, observed with RCM and OCT. Spongiosis, corresponding to dark areas within the epidermis with RCM and OCT, was the main feature of spongiotic dermatitis. Interface dermatitis was characterised by dermoepidermal junction obscuration. Blisters, typical of bullous diseases, were visualised as dark areas with RCM and OCT while scleroderma lesions were characterised by dermoscopic fibrotic beams, related to dermal thickness variations, with specific OCT and histopathologic correlations. Conclusions: Although the role of RCM and OCT has yet to be defined in clinical practice, non-invasive skin imaging shows promising results on inflammatory and autoimmune skin diseases, due to the correlation with histopathologic features.