Relationship between UV-Induced Erythema and Pigmentation Dose-response Angles and The Predictors of Cutaneous Sensitivity to UV Light

Kim, Byoung Kook; Park, Seok Beom; Youn, Jai Il

Abstract

BACKGROUND: There are many predictors of sensitivity to UVR, but controversies exist about their objectivity, correlation between them, and applicability to various races.
OBJECTIVE
In 42 healthy volunteers, we assessed the validaty of dose response angle of erythe ma(DRAE) and delayed tanning(DRADT) after UVB irradiation, and also evaluated the correlation hetween dose-response angb s and other predictors of UV sensitivity.
METHODS
We measured erythema and melanin index using reflectance spectrophotometer aft,er irradiation of UVB on the back of 42 males. When the erythema index and melanin index were plotted against UV doses for each patient, a dose response curve was obtained. Linear regression analysis was used to calculate the slope of those curves for erythema and delayed tanning, which were called DRAE and DRADl respectively. Also we checked predictots of UV sensitivity such as skin type, MED, MMD, consiitutional and facultative skin color, then analyzed the relation be tween dose response angles and other predictors.
RESULTS
Statistically significa it linear regression lines were obtained from 41 subjects regarding to erythema and frorn 31 subjects regarding to delayed tanning. As for the relationship he tween the pvedictors of UV senitivity, only the MED correlated well with DRAE.
CONCLUSION
We found that dose response angles, especially DRAE, were an objective and adequate predictor of cutaneous LJV sensitivity, but could not find validity of skin type and skin color in Koreans. A more organized study with a larger number of subjects is needed to clarify the usefulness of the predictors.