Otman S G H, Edwards C, Pearse A D, Gambles B J, Anstey A V
Department of Dermatology, Royal Gwent Hospital, Newport, Gwent, and Department of Dermatology, Cardiff University, College of Medicine, UK.
Br J Dermatol. 2006 May;154(5):963-8. doi: 10.1111/j.1365-2133.2006.07171.x.
Patients with psoriasis undergoing or about to undergo ultraviolet (UV) phototherapy and photochemotherapy often have thick scale on their plaques which can prevent the penetration of UV radiation. Emollients are used to moisturize the skin and to prevent or reduce some of the milder side-effects ('dryness', itching) sometimes experienced during UV therapy. However, emollients can alter the UV transmission of skin and thus may alter the clinical effects of phototherapy and photochemotherapy.
We tested 30 of the topical emollients in the British National Formulary (BNF) using a standard in vitro technique used to test sunscreens. We also surveyed U.K. phototherapy units to establish routine practice for emollient use in phototherapy and photochemotherapy.
We used a standard in vitro technique to measure the monochromatic protection factors (MPFs) of 30 non-bath emollients from the BNF. An application rate of 2 mg cm-2 was used. For the assessment of effects during narrowband UVB (TL-01) phototherapy, the mean of the protection factors at 310 and 315 nm was calculated; for psoralen plus UVA photochemotherapy the mean UVA protection factor was used. A questionnaire survey was used to assess routine practice concerning emollient use prior to phototherapies in phototherapy units throughout the U.K.
In the UVA range, 17 of the 30 emollients gave protection factors of 1.2 or above. In the UVB range, 23 of 30 had an MPF of 1.2 or above. Yellow soft paraffin had the highest protection factor in the UVB range. Of 78 centres surveyed, 57 returned completed questionnaires (73%). Seventeen of 57 (30%) centres routinely used emollients immediately prior to administering phototherapy treatments. The remaining 40 of 57 (70%) did not. Forty-five (79%) responding centres recommended the use of emollients after phototherapy.
This study has revealed considerable variability in the practice of emollient use before phototherapy treatments. Although the majority of centres included in this study did not routinely use emollients, almost one third did. Our in vitro measurement of 30 emollients revealed marked variation in UV transmission, with many emollients blocking sufficient UV to affect the response to therapy.
正在接受或即将接受紫外线（UV）光疗和光化学疗法的银屑病患者，其斑块上通常有厚厚的鳞屑，这会阻碍紫外线辐射的穿透。润肤剂用于滋润皮肤，并预防或减轻紫外线治疗期间有时会出现的一些较轻微的副作用（“干燥”、瘙痒）。然而，润肤剂会改变皮肤的紫外线透射率，从而可能改变光疗和光化学疗法的临床效果。
我们使用一种用于测试防晒霜的标准体外技术，对英国国家处方集（BNF）中的30种外用润肤剂进行了测试。我们还对英国的光疗单位进行了调查，以确定在光疗和光化学疗法中使用润肤剂的常规做法。
我们使用标准体外技术测量了BNF中30种非沐浴用润肤剂的单色防护因子（MPF）。使用的涂抹率为2mg/cm²。为了评估窄带UVB（TL-01）光疗期间的效果，计算了310和315nm处防护因子的平均值；对于补骨脂素加UVA光化学疗法，则使用平均UVA防护因子。通过问卷调查来评估英国各地光疗单位在光疗前使用润肤剂的常规做法。
在UVA范围内，30种润肤剂中有17种的防护因子为1.2或更高。在UVB范围内，30种中有23种的MPF为1.2或更高。黄软石蜡在UVB范围内的防护因子最高。在接受调查的78个中心中，57个返回了完整的问卷（73%）。57个中心中有17个（30%）在进行光疗前常规使用润肤剂。其余57个中心中的40个（70%）没有。45个（79%）回复的中心建议在光疗后使用润肤剂。
本研究揭示了光疗前使用润肤剂的做法存在很大差异。尽管本研究中的大多数中心没有常规使用润肤剂，但几乎三分之一的中心这样做了。我们对30种润肤剂的体外测量显示，紫外线透射率存在显著差异，许多润肤剂阻挡了足够的紫外线，从而影响治疗反应。
