People with Fitzpatrick phototypes (IV-VI) appear to be vulnerable to sun-exposure-driven premature aging, though the damage appears later than in lighter skin.
These findings come from researchers at the University of Manchester, U.K., and Johns Hopkins University School of Medicine in Baltimore, who report in a press release that the findings dispel the myth that people with black skin are largely protected from sun damage because of the high pigment content of their skin.
The study included 21 people in their early 20s and 18 people in their 60s and 70s, and is the first to analyze how skin structure and elasticity changes with age in people with Fitzpatrick IV-VI skin types.
“We know repeated exposure to the sun can age white skin, but very little research has been carried out on black people,” lead researcher Dr. Abigail Langton from The University of Manchester said in the release.
“This research shows that black skin is indeed affected by the sun, though it takes far longer for that effect to be felt.”
The team analyzed two skin sites: the buttock, and the forearm. This allowed them to compare skin in a region typically protected from sun damage to that in an area which receives regular exposure to the sun. Skin elasticity, as well as levels of fibrillin and collagen, were measured.
Protected black buttock skin performed similarly in both young and old subjects: the older cohort showed only small differences in elasticity. However, the sun-exposed forearm skin showed significant changes in older black volunteers: it was much less elastic, and fibrillin and collagen were reduced.
The study is published online ahead of print in the Journal of Investigative Dermatology (Nov. 4, 2018).
Professor Rachel Watson, from The University of Manchester, said: “Our previous work has shown that there are differences in how skin is organized in black and white skin; clinicians are often unaware of this difference. There is certainly a need to take this into account when considering treatment options for all patients."
Dr. Watson said that most dermatological research is conducted in parts of the world where there are fewer people with darker skin types and ethnic backgrounds, which could explain the lack of data on dark skin.
There is a growing interest in differences in skin function in different population groups and Fitzpatrick skin types. In Canada, the annual Skin Spectrum Summit professional meeting brings the newest science in this field to an audience of medical professionals with an interest in skin of colour.