不同波长紫外线照射后皮肤颜色的变化  

Changes of skin complexion after ultraviolet A （UVA） and ultraviolet B （UVB） exposure

作　　者：袁超[1] 王学民[1] 谈益妹[1] 杨丽洁[1] 李宁[1] 

机构地区：[1]上海市皮肤病性病医院皮肤与化妆品研究室,200050

出　　处：《中华皮肤科杂志》2010年第2期88-90,共3页Chinese Journal of Dermatology

摘　　要：目的观察不同波长紫外线照射皮肤后，颜色变化的过程。方法用双倍剂量最小持续性黑化量和最小红斑量对10例Ⅲ型受试者皮肤进行照射，通过临床评分、扫描反射比分光光度仪和窄谱反射分光光度计三种方法对照射后的皮肤进行14天的评价和测定。结果UVB照射后，a＊值和红斑指数（EI值）在照射后6h急剧增加，照射后2天达到高峰；L丰值在照射后1天出现急剧降低；ITA°在第7天显著降低；黑素指数（MI值）在照射后2天内有逆向的降低趋势，直到照射后7天才有显著增高。在UVA照射下，a＊值和EI值改变不明显；p值在照射后6h出现显著降低；ITA°在第14天达到最低值；MI值仅照射后1天有显著增高。结论UVA和UVB照射后的皮肤颜色改变在时间动力学和反应程度方面有明显区别。a＊值和EI值是评价照射后日晒伤较为敏感而准确的参数，而ITA°和MI值是评价晒斑较好的参数。Objective To observe the alteration of skin complexion ＂after UVA and UVB exposure. Methods The back skin of ten females with skin type Ⅲ was subjected to single exposure to solar-simulated UVA of double minimal persistent pigment darkening （MPPD） or UVB of double minimal erythema close （MED）. Skin reflectance was assessed with clinical grading, spectcolometer and Mexameter MX 18 before irradiation, 6 hours, 1, 7 and 14 days after the irradiation. Results After UVB irradiation, a＊ value and erythema index （EI） abruptly increased at 6 hours and peaked on clay 2; L＊ value sharply declined on clay 1; ITA° markedly decreased on clay 7; melanin index （MI） declined within the first 2 days, hut notably increased on clay 7. After UVA irradiation, a＊ and El value experienced no apparent changes; L＊ value obviously declined at 6 hours; ITA° reached its lowest value on clay 14; MI increased only on day 1. Conclusions There is a significant difference in the kinetics and extent of skin complexion changes after UVA and UVB irradiation. EI and a＊ value are sensitive and accurate indices for evaluating sunburn, and MI and ITA° for analyzing tanning.

关 键 词：紫外线 皮肤颜色 L＊值 a＊值 MI值 EI值 

分 类 号：R751[医药卫生—皮肤病学与性病学]