Abstract: HUANG Chun-yun, YAN Shu-xian, XIANG Lei-hong, MA Li, HU Yue, XU Yu. Department of Dermatology, Huashan Hospital; Department of Dermatology and Venereology, Shanghai Medical College, Fudan University, Shanghai 200040, China Corresponding author: YAN Shu-xian, Email: shuxianyan@yahoo.com.cn 【Abstract】 Objective To estimate the effect of sun protection education on the severity and treatment of polymorphous light eruption （PLE）. Methods Sixty-two patients with PLE were enrolled in this study, and randomly assigned into the control group （n = 31） and intervention group （n = 31） by using a random number table. Routine therapy was provided to all the subjects at their visits. The intervention group attended two lectures on sun protection at the beginning of spring and summer, and was given an education manual after each lecture. All the subjects completed a face to face interview and a questionnaire on the severity and therapy of PLE at the baseline and 12 months after enrollment. SPSS 11.5 software was used for data processing. Rank sum test, t test and chi-square test were carried out to assess the differences in the severity and treatment of PLE between the control group and intervention group as well as between pre- and post-intervention. Results The patients receiving sun protection education showed a significant decrease in the severity of PLE, including the number of months affected by PLE （t = 4.611, P < 0.01）, number of PLE episodes （t = 3.569, P < 0.01）, frequency of facial involvement （Z = 2.369, P < 0.05） and the time taken for lesions to appear after sun exposure （Z = 2.650, P < 0.01） in the year after enrollment compared with that before enrollment. Significant differences were also observed between the intervention group and control group in the number of months affected by PLE （t = 3.679, P < 0.01）, number of PLE episodes （t = 2.995, P < 0.05）, frequency of facial involvement （Z = 2.169, P < 0.05）, the time taken for lesions to appear after sun exposure （Z = 2.169, P < 0.05） in the year after enrollment. The percentage of patients applying highly potent topical glucocorticosteroids （χ2 = 10.928, P < 0.01）and administrating antihistamines （χ2 = 18.723, P < 0.01） as well as the cumulative time of treatment with oral antihistamines （Z = 2.656，P < 0.01） were significantly reduced in the intervention group in the year after enrollment than in that before enrollment. Further more, a marked decrease was found in the percentage of patients applying topical highly potent glucocorticosteroids （χ2 = 4.521, P < 0.05） and administrating antihistamines（χ2 = 10.949, P < 0.01） as well as the cumulative time of treatment with oral antihistamines （Z = 3.353, P < 0.01）. Conclusions Sun protection education through lectures and manuals appears to be an efficient adjuvant for the relief of PLE severity as well as for the reduction in the use of antihistamines and glucocorticosteroids, suggesting that dermatologists should pay more attention to sun protection education in the treatment of photosensitive diseases. 【Key words】 Ultraviolet rays; Patient education; Photosensitivity disorders