Duteil L, Ortonne J P
Centre de Pharmacologie Clinique Appliquée à la Dermatologie, Nice, France.
Photodermatol Photoimmunol Photomed. 1992 Apr;9(2):67-71.
A 20% azelaic acid (AZA) cream is currently used as a therapeutic agent in the treatment of acne vulgaris. Therefore, this product is intended to be applied on frequently or continuously sun-exposed skin. In certain disorders of hyperpigmentation, AZA has been reported to have a depigmenting effect as well, while showing no significant activity on normal skin. It has been suggested that AZA selectively inhibits hyperactive or malignant melanocytes. Knowing that light-stimulated melanocytes are in a state of hyperactivity, it seemed worthwhile to investigate AZA activity on light-induced skin pigmentation. This study aimed to assess the activity of 20% AZA cream on light-induced skin pigmentation in 10 subjects. There were 5 test zones, all located on the middle of the back: 2 were treated with AZA cream, 2 others with the vehicle and 1 was left untreated. Each product was applied twice daily, 5 days a week, for 4 weeks on one zone, and for 5 weeks on the other. In the middle of the fourth week, the tested zones were exposed to ultraviolet B (UVB) + UVA + visible light, with a total of 3 times the minimal erythema dose distributed progressively over 3 consecutive days. Seven and 10 days after the last irradiation, the induced photopigmentation was assessed by colorimetric and visual means. Compared with its vehicle, the AZA cream had neither a depigmenting effect nor a preventive effect on the light-acquired skin pigmentation. Moreover, interrupting or continuing the AZA treatment after skin irradiation had no influence on the resulting pigmentation.
20%壬二酸（AZA）乳膏目前被用作治疗寻常痤疮的药物。因此，该产品旨在用于经常或持续暴露于阳光下的皮肤。在某些色素沉着过度的病症中，据报道AZA也具有脱色作用，而对正常皮肤无明显活性。有人提出AZA可选择性抑制过度活跃或恶性的黑素细胞。鉴于光刺激的黑素细胞处于活跃状态，研究AZA对光诱导的皮肤色素沉着的活性似乎是值得的。本研究旨在评估20% AZA乳膏对10名受试者光诱导的皮肤色素沉着的活性。有5个测试区域，均位于背部中部：2个区域用AZA乳膏治疗，另外2个区域用赋形剂治疗，1个区域不进行治疗。每种产品每天涂抹两次，每周5天，在一个区域涂抹4周，在另一个区域涂抹5周。在第四周中旬，将测试区域暴露于紫外线B（UVB）+紫外线A（UVA）+可见光下，总共3倍的最小红斑剂量在连续3天内逐渐分布。在最后一次照射后7天和10天，通过比色法和视觉方法评估诱导的光色素沉着。与赋形剂相比，AZA乳膏对光诱导的皮肤色素沉着既没有脱色作用也没有预防作用。此外，皮肤照射后中断或继续使用AZA治疗对最终的色素沉着没有影响。
