The importance of using a diverse range of skin in aesthetic dermatology testing

In aesthetic dermatology, ensuring that products are safe and effective for all skin types is paramount. This inclusivity is not a matter of ethics but is a scientific necessity. At Ten Bio, we leverage our TenSkin™ technology to provide comprehensive testing across all Fitzpatrick skin types, from very fair (Type I) to very dark (Type VI), ensuring that the results we achieve for our clients can be universally applicable and relevant. Each skin type has unique characteristics and responses to treatments, necessitating tailored approaches in dermatological testing and product development.

Understanding variations in skin

Biological differences in skin across different ethnicities are primarily influenced by genetic factors that affect skin structure, pigmentation, and response to environmental conditions. Here is a summary of the key differences:

Melanin content  Melanin is the primary determinant of skin color, with higher melanin levels leading to darker skin tones. Ethnicities with darker skin have more eumelanin, which provides greater protection against UV radiation, reducing the risk of sunburn and skin cancerThese darker skin types can, however, have much higher incidences of post-inflammatory hyperpigmentation (PIH). Lighter-skinned individuals, typically from northern latitudes, have less melanin, making them more susceptible to UV damage, but allowing better synthesis of vitamin D in low-light conditions [1, 2]. 

 

Skin structure and function – The stratum corneum, the outermost layer of the skin, can vary in thickness and structure between ethnicities. Individuals with darker skin tend to have more densely packed layers in the stratum corneum, which can lead to greater resistance to mechanical stress and a lower incidence of irritant dermatitis. Conversely, lighter skin types may have a thinner stratum corneum, which can make them more prone to irritant dermatitis [3]. Studies have also shown that skin penetration following topical application can vary based on these differences.

Response to injury and healing Key differences in response can be observed between different skin tones. While lighter skin may show more rapid and pronounced erythema (redness), darker skin is prone to post-inflammation hyperpigmentation and keloid scarring [4].

Aging process – Aging is universally inevitable and typically signified by changes in skin elasticity and an increase in uneven skin color. However, the timing and degree to which these effects become evident can vary significantly across different skin types. While darker pigmentation, a result of higher melanin concentrations, can protect against or delay photoaging effects, it can make a person more susceptible to dyspigmentation. Lighter skin generally shows aging signs earlier, with fine lines and wrinkles becoming more evident due to a loss in volume, while darker skin maintains elasticity longer due to an inherently thicker and more densely packed dermis [5, 6].

Inclusivity in testing matters

Enhanced understanding of skin physiology. Testing on a broad range of skin types allows for a more comprehensive understanding of skin physiology. At Ten Bio, our use of full-thickness human skin explants from a variety of donors, including those with different ethnic backgrounds, helps us study these differences in detail. This approach ensures that we can evaluate not only how diverse skin types respond to certain stimuli (e.g., wounding, pollution exposure, solar radiation, etc.), we can test the efficacy and safety of products in a way that is representative of the target population.

Improved product development. By incorporating a range of Fitzpatrick types in our skin testing services, we can predict product performance more accurately across different skin tones to ensure our clients are in receipt of the most robust data which can be applied to their future product development planning. This inclusivity leads to the development of treatments that can be effective for everyone or equally target those specific issues that are more prevalent in certain skin types, reducing the risk of adverse reactions and enhancing overall patient satisfaction.

The role of TenSkin™ in skin testing

Our TenSkin™ model is designed to maintain skin’s natural physiological tension, which helps to preserve its structural integrity and normal homeostasis. This innovative approach enables us to conduct long-term studies that mimic in vivo conditions more closely than traditional models. As a result, we can investigate complex skin responses with a high degree of accuracy and predictability as to what researchers will see in the clinic.

We have established a network of surgical partners to source ethically consented surplus surgical tissue from a wide range of donors. This access to various skin types allows us to explore how different phototypes respond to treatments, leading to more robust and applicable data to the very significant benefit of our clients’ future product planning.

 

 

Scientific insights and future directions

Incorporating all Fitzpatrick types in aesthetic dermatology testing is not just a best practice—it is a scientific imperative. Indeed, a recent review highlighting the potential for AI use in dermatology noted the potential for significant bias in these models due to a lack of training data in different skin types [7]. At Ten Bio, we are committed to leading the way in testing, ensuring that we deliver optimal results for all skin types. Visit Ten Bio to learn more about our innovative solutions that can be readily applied to the benefit of your ongoing research programs.

References

  1. Tadokoro, T., Yamaguchi, Y., Batzer, J., Coelho, S. G., Zmudzka, B. Z., Miller, S. A., Wolber, R., Beer, J. Z., & Hearing, V. J. (2005). Mechanisms of skin tanning in different racial/ethnic groups in response to ultraviolet radiation. Journal of Investigative Dermatology, 124(6), 1326–1332. https://doi.org/10.1111/j.0022-202X.2005.23760.x
  2. Elbuluk N, Grimes P, Chien A, Hamzavi I, Alexis A, Taylor S, Gonzalez N, Weiss J, Desai SR, Kang S. The Pathogenesis and Management of Acne-Induced Post-inflammatory Hyperpigmentation. Am J Clin Dermatol. 2021 Nov;22(6):829-836. doi: 10.1007/s40257-021-00633-4.
  3. Agarwal, S. (2023, May 1). Histology, skin. StatPearls [Internet]. https://www.ncbi.nlm.nih.gov/books/NBK537325/#article-32669.s1
  4. Brown, J. J., & Bayat, A. (2009, July 1). Genetic susceptibility to raised dermal scarring. OUP Academic. https://doi.org/10.1111/j.1365-2133.2009.09258.x
  5. NA;, V. S. M. (2019, April 1). Aging in skin of color. Clinics in dermatology. https://doi.org/10.1016/j.clindermatol.2019.04.010
  6. Ethnicity affects how our skin ages, here’s why. Cosmetics Business. (2024, June 10). https://cosmeticsbusiness.com/ethnicity-affects-skin-ages-170912
  7. Venkatesh, K.P., Raza, M.M., Nickel, G. et al.Deep learning models across the range of skin disease. npj Digit. Med. 7, 32 (2024). https://doi.org/10.1038/s41746-024-01033-8

Ten Bio team, Aug 2024