Build a solid foundation in science, formulation and product development—find out more!
Most Popular in:
Variations in Pigmentation and Ultrastructural Skin Differences Among Ethnic Groups
By: Rupa Pugashetti, MD, Santa Clara Valley Medical Center, and Howard I. Maibach, MD, University of California School of Medicine
Posted: September 1, 2010, from the September 2010 issue of Cosmetics & Toiletries.
page 6 of 6
Tristimulus colorimeter: Alaluf et al. examined the impact of epidermal melanin in different ethnic skin types on the objective measurements of human skin color22 taken by a tristimulus chromameter. L*, a*, b* measurements were made in European, Mexican, Chinese, Indian and African subjects. Overall, darker skin types tended to have lower L* values, higher a* values and higher b* values, compared with constitutively lighter skin types. Results demonstrated that total epidermal melanin is the primary determinant of L* values. Melanosome size also had a significant influence on L* values, and larger melanosomes are associated with a darker skin color, as previously discussed. Based on the strength of correlations observed in this study, epidermal melanin content still appears to play a greater role in determining skin color than melanosome size.
Many advances have been made in understanding the genetic, molecular and cellular differences underlying normal variation in human skin pigmentation. However, further studies must be carried out to investigate the genetic pathway underlying melanin synthesis, the role of genetic variation in epidermal pigmentation, and to elucidate differences in skin pathophysiology among humans from different ethnic backgrounds. Understanding the differences in pigmentation and skin structure and function among varying ethnic types can assist chemists and formulators in developing products to target the different needs of diverse skin types. Reproduction of the article without expressed consent is strictly prohibited.
Send e-mail to email@example.com.
1. US Census Bureau, Interim projections by age, sex, race, and Hispanic origin, 2004, http://www.census.gov/population/www/projections/usinterimproj/ (Accessed Jul 14, 2010)
2. W Montagna and K Carlisle, The architecture of black and white facial skin, J Am Acad Dermatol 24 929–937 (1991)
3. G Szabo, AB Gerald and MA Pathak, Racial differences in human pigmentation on the ultrastructural level, J Cell Biol 39 132a–133a (1968)
4. K Toda, MA Pathak, JA Parrish, TB Fitzpatrick and WC Quevedo Jr, Alteration of racial differences in melanosome distribution in human epidermis after exposure to ultraviolet light, Nat New Biol 236 143–145 (1972)
5. G Szabo, The number of melanocytes in human epidermis, Br Med J 1 1016–1017 (1954)
6. AJ Thody and SA Burchill, Epidermal eumelanin and phaeomelanin concentrations in different skin types and in response to PUVA, Br J Dermatol 123 842–845 (1990)
7. HY Thong, SH Jee, CC Sun and RE Boissy, The patterns of melanosome distribution in keratinocytes of human skin as one determining factor of skin color, Br J Dermatol 149 498–505 (2003)
8. L Minwalla, Y Zhao, IC Le Poole, RR Wickett, RE Boissy, Keratinocytes play a role in regulating distribution patterns of recipient melanosomes in vitro, J Invest Dermatol 117 341–347 (2001)
9. S Alaluf, D Atkins, K Barrett, M Blount, N Carter and A Heath, Ethnic variation in melanin content and composition in photoexposed and photoprotected human skin, Pigment Cell Res 15 112–118 (2002)
10. KM Halprin and A Ohkawara, Glutathione and human pigmentation, Arch Derm 94 355–357 (1966)
11. W Westerhof, Evolutionary, biologic, and social aspects of skin color, Dermatol Clin 25 293–302 (2007)
12. K Makova K and H Norton, Worldwide polymorphism at the MC1R locus and normal pigmentation variation in humans, Peptides 26 1901–1908 (2005)
13. MD Shriver et al, Skin pigmentation, biogeographical ancestry and admixture mapping, Hum Genet 112 387–399 (2003)
14. RL Lamason et al, SLC24A5, a putative cation exchanger, affects pigmentation in zebrafish and humans, Science 310 1782–1786 (2005)
15. HL Norton, et al, Genetic evidence for the convergent evolution of light skin in Europeans and East Asians, Mol Biol Evol 24 710–722 (2007)
16. A Gibbons, American Association of Physical Anthropologists meeting, European skin turned pale only recently, gene suggests, Science 316 364 (2007)
17. T Tadokoro et al, Mechanisms of skin tanning in different racial/ethnic groups in response to ultraviolet radiation, J Invest Dermatol 124 1326–1332 (2005)
18. RL Olson, J Gaylor and MA Everett, Skin color, melanin and erythema, Arch Dermatol 108 541–544 (1973)
19. RL Olson, J Nordquist and MA Everett, The role of lysosomes in melanin physiology, Br J Dermatol 83 189–199 (1970)
20. JA Lee, S Osmanovic , MAG Viana, R Kapur, B Meghpara and DP Edward, Objective measurement of periocular pigmentation, Photodermatol Photoimmunol Photomed 24 285–290 (2008)
21. MD Shriver and EJ Parra, Comparison of narrow-band reflectance spectroscopy and tristimulus colorimetry for measurements of skin and hair color in persons of different biological ancestry, Am J Phys Anthropol 112 17–27 (2000)
22. S Alaluf, D Atkins, K Barrett, M Blount, N Carter and A Heath, The impact of epidermal melanin on objective measurements of human skin color, Pigment Cell Res 15 119–126 (2002)
*Revised with permission from: R Pugashetti and H Maibach, Pigmentation in Ethnic Groups, ch 52 in Aging Skin, MA Farage, KW Miller and HI Maibach, eds, New York: Springer (2010) pp 503–508