Erythema and Melanin Index According to UVB Radiation Doses by Use of a Reflectance Spectrophotometer in Korean Young Adults

Park, Seok Beom; Kim, Byoung Kook; Eun, Hee Chul; Youn, Jai Il

Abstract

BACKGROUND: Methods of estimating the erythema and pigmentation reactions, such as MPE (Minimal Perceptible Erythema), ME(Minimal Erythema Dose) and MMD(Minimal Melanogenic Dose), are vulnerable to the variations of subjective visual measurements.
OBJECTIVE
By using objective and quantitative methods, the erythema and pigmentaton responses were investigated.
METHODS
A sunlight, fluorescent lamp(Waldmann UV 800) was used as a UVB light source. Multiple sites of the lower back were irradiated with an increasing dose by a constant amount, With a reflectance spectrophotometer (DermaSpectrometer(R)), erythema and melanin indices at control, MPE, MED, MMD sites were assessed. The dose-response angle of erythema and pigmentation were calculated.
RESULTS
The erythema and pigmetation indices at the control, MPE, MED and MMD sites were 8.7+/-2.0AU/30.5+/-2.6AU, 10.5+/-2.7AU/32.6+/-3.6AU, 13.2+/-3.5AU/32.6+/-3.3AU, and 10.4+/-3.0AU/ 33.5+/-2.7AU, respectively. The calculated dose-response angle accurately measured the response of skin to UVB irradiation.
CONCLUSION
In this study, use of a reflectance spectrophotometer appeared to be a more sensitive and effective method than visual assessment, in addition, dose-response angles may be an objective index for determination of skin responses to UVB irradiation.