Assessing the role of race in quantitative measures of skin pigmentation and clinical assessments of photosensitivity.
ABSTRACT Given the increasing demographic diversity in the United States, clarifying relationships between race, color, ethnicity, and disease processes is critical.
We sought to examine the correlation between objective measures of skin pigmentation, racial identification, and physician-diagnosed and self-reported skin phototypes.
A total of 558 participants (76 nonwhite) were evaluated. A subset underwent spectrometric readings and digital photography of the upper aspect of the inner arm. Self-identified race was compared with 7 measures of pigmentation.
Race correlates best with physician-diagnosed skin phototype (r = 0.55, P < .01), whereas self-reported skin phototype, spectrometry, and colorimetry correlate poorly with race (r = 0.28, < 0.40, and r > -0.31, respectively, P < .01). Associations between race and subjective measures strengthen among patients with darker skin.
Objective measures of pigmentation fail to correlate well with race, whereas race correlates moderately with physician-diagnosed skin phototype. Including objective methods of analyzing skin color may reduce subjective influences of race in assessing photosensitivity and potential risk for skin cancer.
- [show abstract] [hide abstract]
ABSTRACT: We have examined the quantity and composition of melanin in both photoprotected (volar upper arm) and chronically photoexposed (dorsal forearm) skin from a range of different ethnic skin types including African, Indian, Mexican, Chinese and European. The most lightly pigmented (European, Chinese and Mexican) skin types have approximately half as much epidermal melanin as the most darkly pigmented (African and Indian) skin types. However, the composition of melanin in these lighter skin types is comparatively more enriched with lightly coloured, alkali-soluble melanin components (up to three-fold). Regardless of ethnicity, epidermal melanin content is significantly greater in chronically photoexposed skin than it is in corresponding photoprotected skin (up to two-fold). However, by comparison there is only a modest enrichment of lightly coloured, alkali soluble melanin components in photoprotected skin (up to 1.3-fold). Analysis of melanosomes extracted from the epidermis in these subjects indicates that the proportion of spheroidal melanosomes is low in all skin types examined (<10%). This suggests that in human skin, pheomelanin is a very minor component of epidermal melanin, even in the lightest (European) skin types. Analysis of melanosome size revealed a significant and progressive variation in size with ethnicity: African skin having the largest melanosomes followed in turn by Indian, Mexican, Chinese and European. On the basis of these findings, we propose that variation in skin pigmentation is strongly influenced by both the amount and the composition (or colour) of the melanin in the epidermis. Variation in melanosome size may also play a significant role. However, the data also suggest that in human skin there are subtle differences in the mechanisms associated with the maintenance of constitutive pigmentation and facultative hyperpigmentation, respectively.Pigment Cell Research 04/2002; 15(2):112-8. · 4.29 Impact Factor
Article: Race and genomics.New England Journal of Medicine 07/2003; 348(25):2581-2; author reply 2581-2. · 51.66 Impact Factor
- Archives of Dermatology 06/2002; 138(5):673-4. · 4.79 Impact Factor