Effects of short-term moisturizer application in different ethnic skin types non-invasive assessment with optical coherence tomography and reflectance confocal microscopy

Background/Aims: Ethnic skin types are known to differ in their morphological and physiological features. Thus, treatment responses may vary among different races. We aimed to assess skin morphology of different ethnicities and to compare the effect of short-term moisturizer application using optical coherence tomography (OCT) and reflectance confocal microscopy (RCM). Methods: Thirty healthy female subjects of European, Asian and Black ethnicity at 30-45 years of age were included in the study. OCT and RCM imaging was performed on the cheek to compare morphology. Following the 2-week application of a moisturizer cream (Sebamed (R) lotion) on one forearm, imaging was performed on both forearms to assess and compare treatment responses. Results: Epidermal thickness and morphology of pores varied between the three ethnic groups, with Black subjects displaying the thickest epidermis and largest skin pores. On the treated forearm, OCT measurements revealed a significantly thicker epidermis in all groups as compared to the untreated forearm. Width of skin folds on the treated forearm was measured by RCM to be significantly lower in all ethnic groups as compared to the untreated forearm. Conclusion: Different ethnic skin types showed variations in skin morphology and treatment response to short-term moisturizer application. OCT and RCM were useful methods for noninvasive, real-time, repeated assessment of ethnic skin.