Pigmentation in sun-exposed skin decreases with increasing age among blacks
Sun-exposed skin in older blacks lightened with age when compared with younger blacks, which was in contrast to findings among whites, according to recently published study results.
Researchers recruited 40 white and 43 black patients between March 2011 and August 2015 at the Johns Hopkins University Hospitals in Baltimore. Patients included men and women who were divided into one of four groups, with at least 20 patients in each group: Whites aged 18 to 30 years, whites aged 65 years and older, blacks aged 18 to 30 years, and blacks aged 65 years and older. Tristimulus colimetry readings were obtained from the buttock (sun-protected site) and back of forearm (sun-exposed site) of each patient.
A questionnaire on demographics and lifestyle factors was completed only by the black patients, since the white patients were being used as controls, according to the researchers.
The older black cohort had lighter forearm skin compared with the younger black cohort (P = .02); however, in a comparison of the two white cohorts, the forearm skin was darker in the older group (P = .03).
The buttock was darker than the forearm in the younger black cohort, while the buttock was lighter than the forearm in the white patients aged 18 to years (P < .001).
In the younger black cohort, supplement use and smoking were associated with a lighter forearm than buttock, and in the older cohort, less recreational sun exposure was associated with a lighter forearm.
“The changes in pigmentation with respect to age and sun exposure differ in [blacks] in comparison with [whites],” the researchers concluded. “In contrast to [whites], we observed decreasing pigmentation with increasing age and darker skin in sun-protected areas compared with sun-exposed areas. Thus, common contributors to skin aging and pigmentation in [whites] may not be applicable to [blacks].” – by Bruce Thiel
Disclosure: The researchers report no relevant financial disclosures.