Department of Dermatology, Hospital Central 'Dr. Ignacio Morones Prieto, Universidad Autónoma de San Luis Potosí, San Luis Potosi, Mexico.
Photodermatol Photoimmunol Photomed. 2014 Feb;30(1):35-42. doi: 10.1111/phpp.12086. Epub 2013 Dec 3.
Melasma is an acquired hyperpigmentation on sun-exposed areas. Multiple approaches are used to treat it, but all include broad ultraviolet (UV)-spectrum sunscreens. Visible light (VL) can induce pigmentary changes similar to those caused by UV radiation on darker-skinned patients.
To assess the efficacy of sunscreen with broad-spectrum UV protection that contains iron oxide as a VL-absorbing pigment (UV-VL) compared with a regular UV-only broad-spectrum sunscreen for melasma patients exposed to intense solar conditions.
Sixty-eight patients with melasma were randomized in two groups to receive either UV-VL sunscreen or UV-only sunscreen, both with sun protection factor ≥ 50, over 8 weeks. All patients received 4% hydroquinone as a depigmenting treatment. At onset and at conclusion of the study, they were assessed by the Melasma Activity and Severity Index (MASI; a subjective scale), colorimetry (L*) and histological analysis of melanin.
Sixty-one patients concluded the study. At 8 weeks, the UV-VL group showed 15%, 28% and 4% greater improvements than the UV-only group in MASI scores, colorimetric values and melanin assessments, respectively.
UV-VL sunscreen enhances the depigmenting efficacy of hydroquinone compared with UV-only sunscreen in treatment of melasma. These findings suggest a role for VL in melasma pathogenesis.
黄褐斑是一种发生于日晒部位的获得性色素沉着。有多种方法可用于治疗黄褐斑，但都包括广谱紫外线（UV）防晒霜。可见光（VL）可诱导色素变化，类似于在深色皮肤患者中由 UV 辐射引起的变化。
评估含有氧化铁作为 VL 吸收颜料的广谱 UV 保护防晒霜（UV-VL）与仅含 UV 的常规广谱防晒霜相比，在暴露于强烈阳光条件下的黄褐斑患者中的疗效。
将 68 例黄褐斑患者随机分为两组，分别接受 UV-VL 防晒霜或仅含 UV 的广谱防晒霜（均具有防晒系数≥50），共 8 周。所有患者均接受 4%氢醌作为脱色治疗。在研究开始和结束时，通过黄褐斑活动和严重程度指数（MASI；主观量表）、比色法（L*）和黑色素组织学分析对患者进行评估。
61 例患者完成了研究。8 周时，UV-VL 组在 MASI 评分、比色值和黑色素评估方面的改善程度分别比 UV 组高 15%、28%和 4%。
与仅含 UV 的防晒霜相比，UV-VL 防晒霜增强了氢醌的脱色效果，这提示 VL 在黄褐斑发病机制中起作用。
