Skin from various ethnic origins and aging: an in vivo cross‐sectional multimodality imaging study

Abstract

Background: Ethnic differences in skin structural features have not been thoroughly investigated, and the few reported studies are contradictory. Thus, we have carried out a set of in vivo measurements on the skin of about 400 volunteers from various ethnic origins living in the same environment. Methods: Female subjects were distributed into four ethnic groups: African Americans, Mexicans, Caucasians, and Chinese. Inter‐ and intra‐ethnic skin structural differences, according to age and anatomic site, were investigated using three non‐invasive skin‐imaging methods: ultrasound (US) at 25 and 150 MHz, and optical coherence tomography (OCT). Results: The thickness of the skin is higher on the cheek compared with the dorsal and ventral forearm, with no ethnic or age‐related specificity. We confirm that the sub‐epidermal non‐echogenic band is a sensitive marker of skin aging, and reveal for the first time that it is less pronounced in African Americans. From OCT images, we bring out evidence that the thickness of the dermal–epidermal junction (DEJ) decreased with age, and was higher in African Americans than in Caucasians. Finally, by comparing US images at 150 MHz with OCT images, we show that papillary dermis thickness can be measured and appears to be quite constant irrespective of age or ethnic group. Conclusion: Our study confirms that skin imaging is very attractive to further our knowledge of the morphology of skin from various ethnic origins. Regarding age effects, quantitative parameters have shown that they would be delayed in African Americans compared with all other ethnic populations.

Effects of Short-Term Moisturizer Application in Different Ethnic Skin Types: Noninvasive Assessment with Optical Coherence Tomography and Reflectance Confocal Microscopy

“…However, unlike other investigations [19, 20], epidermal thickness significantly differed among the three ethnic groups with the following decreasing order: Blacks > Asians > Caucasians. Querleux et al [19] measured the skin thickness in different ethnic groups using ultrasound and reported that the skin (epidermis + dermis) and subepidermal nonechogenic band representing dermis were thicker on the cheek in all groups comparing to the arm. When the measurements of this study are evaluated, a thicker epidermal layer on the cheek is detectable as compared to the epidermal thickness of the volar arm [19].…”

“…Noninvasive in vivo imaging methods such as OCT and RCM provide real time, painless and repeated monitoring and quantification of the tissues. Few studies have been performed regarding the assessment of skin morphology in different ethnic groups with noninvasive imaging methods [19, 20]. However, to the best of our knowledge, interethnic comparison of noninvasive treatment follow-up has not been performed to date.…”

“…Querleux et al [19] measured the skin thickness in different ethnic groups using ultrasound and reported that the skin (epidermis + dermis) and subepidermal nonechogenic band representing dermis were thicker on the cheek in all groups comparing to the arm. When the measurements of this study are evaluated, a thicker epidermal layer on the cheek is detectable as compared to the epidermal thickness of the volar arm [19]. Our results, however, showed a thicker epidermis on the arm than on the cheek, which is in accordance with the information in textbooks of Dermatology [28].…”

“…Few studies have been performed regarding the assessment of skin morphology in different races with skin imaging methods [19, 20]; however, interethnic comparison of noninvasive treatment follow-up has not been performed yet. In this study, we aimed to assess the skin morphology in light- and dark-skinned females of different ethnic groups and compare the effects of short-term moisturizer application using OCT and RCM.…”

In Vivo, In Situ Imaging of Microneedle Insertion into the Skin of Human Volunteers Using Optical Coherence Tomography

“…OCT is a non-invasive interferometric technique that is capable of resolving skin architecture, in vivo and in real time, at micrometer scale and up to a depth of 1-2 mm, solely based on local optical backscatter (31,32). The principles of OCT are often likened to ultrasound, and the technology has been used to characterise structural and biomechanical features of both 'normal' and diseased human skin (33)(34)(35)(36)(37)(38)(39). Whilst OCT is establishing itself as a routine imaging method in ophthalmology, the evaluation of skin is at a more developmental stage.…”