Department of Pediatric Dermatovenerology, Comenius University, Bratislava, Slovak Republic.
Skin Res Technol. 2014 Feb;20(1):108-15. doi: 10.1111/srt.12092. Epub 2013 Jun 25.
Visual clinical methods of skin color evaluation for diagnostic purposes are so far mostly subjective and thus inaccurate. We present a modified method of melanin amount measurement based on diffuse reflectance spectroscopy (DRS). This method is non-invasive and objective, and allows easy quantification and comparison of melanin levels.
Skin pigmentation was measured by DRS method in 0-18 year old patients at the Department of Pediatric Dermatovenerology, School of Medicine Comenius University Bratislava. Patients were treated for their vitiligo by Balneo PUVA treatment twice weekly. Each patient had measured his remittance spectra from the treated vitiliginous skin before the treatment was started, after 10 irradiations of Balneo PUVA and at the end of the treatment after 25 irradiations of Balneo PUVA. In our study as a reference skin for spectroscopic assessment of melanin in vivo was used the averaged remittance spectra (measured on the inner arm) from the sample of 10 albino patients. The remittance spectra obtained from the vitiligo patients were ratioed against the newly described remittance reference albino skin. We exploited the linear behavior of the spectral curve in the 620-720 nm interval (significant for melanin absorption) and used the slope of the regression line to compute the quantification index α.
By clinical examination before the Balneo PUVA therapy, after the 10th dose of Balneo PUVA therapy as well as at the end of the complete course of Balneo PUVA therapy (after 25 irradiations) we recorded a marked increase of pigmentation in all treated patients for their vitiligo. In each patient the values of melanin quantification angle α were calculated. Statistically we found a significant difference between the melanin quantification angle α in vitiliginous skin before, during the 10th dose of treatment and after the treatment. Similar significant difference was also observed between treated and non-involved skin. We could confirm a clear association between clinical visual examination of treated vitiligo lesions, objective data collected by DRS and melanin quantification angle α.
By using a new standard for the reference skin (albino skin) we could more exactly compare melanin levels in different subjects. Our proposed melanin quantification angle α expresses the extent of the difference in melanin levels between the examined skin lesions. We successfully used this index to quantify the variations of melanin (progress of repigmentation) throughout different stages of treatment of the same lesion and also to objectively evaluate the final effect of the therapy. In the present study, we showed that the diffuse reflectance spectroscopy (DRS) may be suitable method to measure skin colour and the content of human skin melanin in vivo.
目前，用于诊断目的的皮肤颜色评估的视觉临床方法大多是主观的，因此不够准确。我们提出了一种基于漫反射光谱（DRS）的黑素含量测量的改良方法。该方法是非侵入性和客观的，允许轻松量化和比较黑素水平。
在布拉迪斯拉发科米纽斯大学医学院儿科皮肤病学系，对 0-18 岁的患者进行了 DRS 方法的皮肤色素沉着测量。接受 Balneo PUVA 治疗的患者每周两次接受治疗。每位患者在开始治疗前、Balneo PUVA 治疗 10 次后和治疗结束时（Balneo PUVA 治疗 25 次后）测量了他的反射光谱。在我们的研究中，作为体内黑素光谱评估的参考皮肤，使用了 10 名白化病患者的平均反射光谱（测量于内臂）。从白癜风患者获得的反射光谱与新描述的反射参考白化病皮肤进行比较。我们利用光谱曲线在 620-720nm 区间内的线性行为（对黑素吸收有重要意义），并使用回归线的斜率来计算量化指数α。
通过 Balneo PUVA 治疗前的临床检查、Balneo PUVA 治疗 10 次后的检查以及 Balneo PUVA 治疗结束后的检查（治疗 25 次后），我们记录了所有接受治疗的白癜风患者的色素沉着明显增加。在每位患者中，计算了黑素量化角α的值。统计上，我们发现白癜风患者在治疗前、治疗 10 次时和治疗后，黑素量化角α之间存在显著差异。在治疗和非受累皮肤之间也观察到类似的显著差异。我们可以证实，对白癜风病变的临床视觉检查、DRS 收集的客观数据和黑素量化角α之间存在明确的关联。
通过使用新的参考皮肤标准（白化病皮肤），我们可以更准确地比较不同个体的黑素水平。我们提出的黑素量化角α表达了检查皮肤病变之间黑素水平差异的程度。我们成功地使用该指数来量化同一病变不同治疗阶段的黑素变化（复色进展），并客观评估治疗的最终效果。在本研究中，我们表明漫反射光谱（DRS）可能是测量皮肤颜色和人体皮肤黑素含量的合适方法。
