Diffuse Reflectance Spectroscopy Versus Mexameter(®) MX18 Measurements of Melanin and Erythema in an African Population.
Melanin provides protection against excess exposure to solar ultraviolet radiation (UVR) and related adverse health effects. Diffuse reflectance spectroscopy (DRS) can be used to calculate cutaneous melanin and erythema, but this is complex and has been mostly used for light-to-medium pigmented skin. Handheld reflectance spectrophotometers, such as the Mexameter(®) MX18, can also be used. We compared DRS-calculated melanin and erythema values with Mexameter melanin and erythema index values to understand how these techniques/measurements correlate in an African population of predominantly deeply pigmented skin. Five hundred and three participants comprised 68.5% self-identified Black African, 9.9% Indian/Asian, 18.4% White and 2.9% Colored. The majority of Black African (45%), Indian/Asian (34%) and Colored (53%) participants self-identified their skin as being "brown." Measured melanin levels increased with darker self-reported skin color. DRS-calculated and Mexameter melanin values demonstrated a positive correlation (Spearman rho = 0.87, P < 0.001). The results from both instruments showed erythema values were strongly correlated with their own melanin values. This finding is considered spurious and may result from the complexity of separating brown and red pigment when using narrowband reflectance techniques. Further work is needed to understand melanin, erythema and color in Black skin given sun-related health risks in vulnerable groups in Africa.
Environment and Health Research Unit, South African Medical Research Council, Pretoria, South Africa.|Department of Geography, Geoinformatics and Meteorology, University of Pretoria, Pretoria, South Africa.
Caradee Y
0000-0001-9608-818X
CY
Wright
National Metrology Institute of South Africa, Pretoria, South Africa.
Aletta E
AE
Karsten
Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY.
Marcus
M
Wilkes
National Laser Centre, Council for Scientific and Industrial Research, Pretoria, South Africa.
Ann
A
Singh
Occupational Hygiene and Health Research Initiative, North-West University, Potchefstroom, South Africa.
Johan
J
du Plessis
Environment and Health Research Unit, South African Medical Research Council, Pretoria, South Africa.
Patricia N
PN
Albers
Ballistics Research Group, Denel Land Systems, Pretoria, South Africa.
Petrus A
PA
Karsten
D000293:Adolescent; D000328:Adult; D000368:Aged; D044466:Asian People; D044383:Black People; D003124:Colorimetry; D004890:Erythema / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008543:Melanins / Q000378:metabolism*; D008875:Middle Aged; D010860:Pigments, Biological / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012880:Skin Pigmentation; D013057:Spectrum Analysis / Q000379:methods*; D044465:White People; D055815:Young Adult
D008543:Melanins; D010860:Pigments, Biological