In a recent article published in the Dermatology Times, Zoe Diana Draelos, MD, addressed some of the complex issues surrounding the physiologic differences in skin across various ethnic groups. Dr. Draelos, who serves as a consulting professor of dermatology at Duke University School of Medicine in Durham, North Carolina, focused on White, African American, and Hispanic individuals, and delved into the most common questions and controversies surrounding this subject.
The below question and answer section is taken directly from the above-mentioned article.
Are there differences in the skin barrier between ethnicities?
The difference in skin barrier between ethnicities is somewhat controversial because there is a great deal of interindividual variation regardless of ethnicity. Most people possess a more robust skin barrier in more temperate climates and a less robust skin barrier in cold and low-humidity environments. Ambient humidity is the most important variable to control when examining ethnic skin differences. Usually, transepidermal water loss measurements are used as the best indicator of skin barrier condition; however, acclimating to the environment in which the measurements are taken is key to accuracy. Most reports hold that skin of African American individuals possesses higher transepidermal water loss than skin of White individuals, although the opposite has also been reported (but less frequently). Higher transepidermal water loss is an indicator of poorer barrier function in African American individuals than in White individuals.
Do differences exist in skin moisturization between ethnicities?
Skin moisturization is usually measured through a technique known as corneometry. Corneometry is an indirect measurement of the water content of the skin through skin conductance. Skin conductance has been reported to be higher in African American and Hispanic individuals than White individuals. This means that skin of African American and Hispanic individuals is naturally better moisturized than skin of White individuals.
What are the physiologic differences in skin lipid content?
Skin lipids are an important component of skin barrier function and are found in the intercellular space between the corneocytes. Absent and/or defective intercellular lipids are found in xerotic eczema and atopic dermatitis but may be induced by excessive surfactant and water exposure. Lipid content is higher in skin of African American individuals than skin of White individuals. In addition, the ratio of ceramides, cholesterol, and free fatty acids is also different.
Do ceramide levels vary between ethnicities?
Ceramides are the first substance synthesized when the skin barrier has been damaged; thus, they are essential to barrier repair. Ceramide levels are 50% lower in skin of African American individuals compared with skin of White individuals. This could explain why African American individuals report a higher incidence of sensitive skin than White individuals. It could also explain why eczema and atopic dermatitis are more prevalent in African American individuals than White individuals.
Does stratum corneum desquamation vary between ethnicities?
Stratum corneum desquamation does vary between ethnicities. Desquamation in skin of African American individuals is 2.5 times greater than desquamation in skin of White individuals. It is often said that skin of African American individuals appears ashier than skin of White individuals. This observation could be due to increased desquamation but also due to the pigment in the desquamating skin scale. Desquamated skin in African American individuals appears brown, but when an air interface is introduced between the skin and the skin scale, the skin scale appears gray and thus resembles ash. This makes the desquamating scale more visible compared with skin scale of White individuals where the white scale is cast against a white background. This makes emollience more important in skin of African American individuals, as emollients are oily substances able to intercalate between the desquamating corneocytes and smooth down the skin scale temporarily until sloughing occurs.
What are the skin structural differences between different ethnicities?
There are other structural differences in skin between African American and White individuals. The stratum corneum is more compact in skin of African American individuals than in skin of White individuals, and the dermis has more closely stacked smaller collagen fiber bundles with surrounding ground substance in skin of African American individuals.
Concluding Thoughts
Dr. Draelo’s examination of the physiologic differences in skin among White, African American, and Hispanic individuals provides crucial insights for dermatologists. The article highlights the importance of tailoring treatment and skincare recommendations to the specific needs of each individual. Taking this approach enhances the effectiveness of dermatologic care while also helping to promote cultural competence in dermatologic settings, leading to better outcomes for all patients.
If you are interested in deepening your understanding of this important topic, we encourage you to explore our Diversity in Derm Digital Education Hub, where you can access a wealth of information on cultural competence and the unique needs of diverse patient populations.
Source:
- Draelos, Z. D., MD. (2024, July 2). The diversity of skin characteristics. Dermatology Times. https://www.dermatologytimes.com/view/the-diversity-of-skin-characteristics
