UVB 조사량에 따른 최소홍반 유도와 피부색 변화의 관찰

The purpose of this study was to examine Korean women`s minimum erythema dose (MED) and changes in skin color index such as erythema and melanin after UVB irradiation. 14 Healthy women as subjects were irradiated to the external part of the women`s upper arms in four different stages (50, 75, 100 and 125 mJ/cm2), their skin was observed with the naked eye and measurement of erythema index (EI) and melanin index (MI) 24 hours later and then for eight weeks. Besides, a survey was conducted on the women to classify their skin type according to Fitzpatrick`s classification of skin types. As a result, the skin of the four women belonged to skin type II; six to skin type III; and four to skin type IV. But there were differences in MED and the degree of skin darkness even among the women. When the higher amount of UVB was irradiated, EI became higher, and MI became lower. Before UVB irradiation, EI had a significant correlation with MI but a very week correlation after UVB irradiation. In conclusion, the amount of UVB irradiation should be between 50 mJ/cm2 and 75 mJ/cm2 for sunscreen effect test and that it should be regulated within the range depending on their skin type. The amount of UVB that generated erythema and made skin color dark was between 75 mJ/cm2 and 100 mJ/cm2.