Farr P M, Diffey B L, Higgins E M, Matthews J N
Department of Dermatology, Royal Victoria Infirmary, Newcastle upon Tyne, U.K.
Br J Dermatol. 1991 May;124(5):443-8. doi: 10.1111/j.1365-2133.1991.tb00623.x.
We have compared the effectiveness of oral 8-methoxypsoralen photochemotherapy (PUVA) using ultraviolet fluorescent lamps with peak emission at either 325, 352 or 370 nm in the treatment of 24 patients with psoriasis. The forearms of each patient were treated three times weekly with two of the three lamps. The erythemal sensitivity of each patient was tested before the first treatment to ensure that equally erythemal doses of radiation were given from each of the lamps. A side-to-side comparison was used to assess response to treatment at weekly intervals for the 6 weeks of the trial. The lamp with peak emission at 325 nm was shown to be significantly superior to either of the other lamps in terms of response assessed at weekly intervals, and time to clearance of psoriasis. An action spectrum, constructed from the median doses required for clearance of psoriasis using each of the lamps, showed that the effectiveness of the radiation decreased exponentially with increasing wavelength throughout the UVA waveband, such that radiation at 320 nm was an order of magnitude more effective than at 360 nm. This suggests that lamps with peak emission around 325 nm will be more effective than those conventionally used in PUVA units with a peak emission at 352 nm. Lamps with peak emission around 325 nm are also highly effective in the treatment of psoriasis with phototherapy alone. Thus a single treatment unit containing these lamps could be used either for PUVA or ultraviolet phototherapy of psoriasis, avoiding duplication or irradiation equipment.
我们比较了使用峰值发射波长分别为325、352或370nm的紫外线荧光灯进行口服8-甲氧基补骨脂素光化学疗法（PUVA）治疗24例银屑病患者的疗效。每位患者的前臂每周用这三种灯中的两种照射三次。在首次治疗前测试每位患者的红斑敏感性，以确保每种灯给予同等红斑剂量的辐射。在试验的6周内，每周进行一次左右对比，以评估治疗反应。就每周评估的反应以及银屑病清除时间而言，峰值发射波长为325nm的灯显著优于其他两种灯。根据使用每种灯清除银屑病所需的中位剂量构建的作用光谱显示，在整个UVA波段，辐射的有效性随波长增加呈指数下降，因此320nm处的辐射比360nm处的辐射有效性高一个数量级。这表明，峰值发射波长在325nm左右的灯比PUVA设备中传统使用的峰值发射波长为352nm的灯更有效。峰值发射波长在325nm左右的灯单独用于光疗治疗银屑病时也非常有效。因此，一个包含这些灯的单一治疗单元可用于银屑病的PUVA或紫外线光疗，避免设备重复或照射。
