Racial/Ethnic Variations in Skin Barrier: Implications for Skin Care Recommendations in Skin of Color

Background: Genetic and environmental factors influence stratum corneum (SC) barrier properties and function. Researchers increasingly focus on biophysical studies that may help clinicians provide their patients with an informed choice on tailormade skincare. This literature review on skin barrier properties comparing different ethnic populations aims to offer insights into the information's clinical relevance. Methods: A literature review followed by panel discussions and an online review process aimed to answer the questions: Are there racial/ethnic differences in the SC barrier structure and healthy skin barrier function? Is there a need for specific cleansers and moisturizers? Results: Ethnic categories based on race and ethnicity are often not well defined and inconsistent across different studies. Studies comparing ethnic groups' physical and biochemical skin barrier properties have reported differences in transepidermal water loss (TEWL), skin lipid levels, pH, and mast cell granule size. However, these studies frequently had methodological flaws, mainly were small, and demonstrated conflicting results. The literature suggests racial/ethnic variations in ceramide content, SC structure, and filaggrin mutations. Furthermore, studies have shown a greater burden of pruritus and atopic dermatitis among Black populations. Data on barrier properties in Hispanic/LatinX and South Asian populations are lacking. Conclusion: Robust comparative studies are needed to understand these basic concepts to help tailor skincare and skin of color patients' education.