Relationship between constitutive skin color and ultraviolet light sensitivity in Koreans

The assessment of skin sensitivity to ultraviolet (UV) radiation is important in treating a variety of skin diseases and preventing the deleterious effects of UV. Although there are many ways to predict the sensitivity to UVR, controversies exist over their objectivity, correlation, and applicability in various races. For the purpose of evaluating the relationship of skin color and UV responsiveness, this study was performed to assess the validity of constitutive skin color for an individual's UV sensitivity in 80 healthy Korean volunteers. The subjects were divided into two groups: a young-aged group with 40 subjects aged 20-39 years and an old-aged group with 40 subjects aged 43-63 years. A minimal erythema dose (MED) of UVB and minimal immediate pigment darkening dose (MIPDD) of UVA were assessed using a fluorescent lamp (Panasol II, National Biologic Co., Twinberg, USA) and a metal-halide lamp (Dermalight 2001, Mutzhas, Munich, Germany), respectively. The constitutive skin color of buttock was measured with a Minolta Chroma Meter CR-300 (Osaka, Japan), using the CIE (Commission International de l'Eclairege) L*a*b* system. Of the three L*a*b*, we used the L* value to estimate the skin color. For the MED and L* values, the values were inversely proportionate (P<0.05) in the young-aged group; however, no correlation existed in the old-aged group. No relationships existed among Fitzpatrick skin type and MED, skin type and MIPDD. The results of this study indicated that the constitutive skin colors in the young-aged group can be an objective and adequate predictor of cutaneous UV sensitivity.