A single-blinded comparative study between the use of glycolic acid 70% peel and the use of topical nanosome vitamin C iontophoresis in the treatment of melasma

Background Melasma is a common pigmentary disorder. Despite the availability of a wide range of skin‐lightening treatments, melasma of skin remains a therapeutic challenge. Objective The aim of this study was to evaluate the efficacy and safety of nanosome vitamin C iontophoresis and to compare the therapeutic effects of nanosome vitamin C iontophoresis vs. glycolic acid peel 70% in the treatment of melasma in Egyptian women. Methods This study included 14 patients of melasma with skin type IV–V taken for a right–left comparison study of six sessions. Glycolic acid 70% peel was applied on the right side, whereas nanosome vitamin C was applied by iontophoresis on the other side. The results are evaluated using the melasma area and severity index score and with photographs at baseline and after six sessions. Also the photographs were evaluated by two single‐blinded physicians before and after sessions. Results Both sides were improved, but the side treated with nanosome vitamin C showed better results. Side effects were few and transient. Conclusion We concluded that nanosome vitamin C is a new, safe and effective, easy and painless method in the treatment of melasma.     

祛斑汤对小鼠皮肤黑素合成影响的研究

目的:观察祛斑汤对雌性C57BL/6J小鼠皮肤黑素合成的影响,为探索该方剂治疗黄褐斑机制提供实验依据。方法:将雌性C57BL/6J小鼠随机分成空白对照组、祛斑汤低(10 g/kg)、中(20 g/kg)、高剂量(40 g/kg)组、维生素C组。各组灌胃给药30 d后皮肤取材。采用免疫组化法观察小鼠皮肤黑素分布。结果:祛斑汤高、中剂量组黑素颗粒阳性反应的黑素细胞平均光密度低于空白对照组,差别有统计学意义(P0.01)。结论:祛斑汤能抑制雌性C57BL/6J小鼠皮肤中黑素合成、降低黑素分布。     

Intravenous vitamin C in the treatment of post‐laser hyperpigmentation for melasma: A short report

Melasma is difficult to treat. Vitamin C, topical and by iontophoresis, has been shown to be useful. When lasers are used, there is a significant incidence of post‐laser hyperpigmentation. There is no single established treatment for the latter. The case history of a 51‐year‐old Chinese woman is presented. Intravenous vitamin C appears to be useful in treating this complication.     

Intradermal tranexamic acid injections to prevent post-inflammatory hyperpigmentation after solar lentigo removal with a Q-switched 532-nm Nd:YAG laser

Introduction: Post-inflammatory hyperpigmentation (PIH) after solar lentigo removal using a Q-switched (QS) 532-nm Nd:YAG laser is a cause for concern. This study aimed to evaluate the efficacy and safety of intradermal injections of tranexamic acid (TA) at reducing the risk of PIH after QS 532-nm Nd:YAG laser treatment of solar lentigines. Methods: Twenty-five patients with 50 solar lentigines on forearms underwent QS 532-nm Nd:YAG laser treatment. Then, TA (50 mg/mL) was injected randomly into one lesion and 0.9% normal saline was injected intradermally into another lesion. Two blinded dermatologists and a Mexameter® evaluated photographs at baseline, and at weeks 2, 4, 8, and 12. Results: At the end of the study, the mean melanin index (MI) had decreased significantly in both groups. The TA group showed a significant reduction in the mean MI compared with that in the control group at week 4 (p = 0.025). The overall PIH rates were 16% and 28% in the TA and control groups, respectively. The side effects of TA were minimal and they were resolved within 1 h. Conclusion: Single dose of intradermal TA (50 mg/mL) injected can reduce the risk of developing PIH 4 weeks after 532-nm QS Nd:YAG laser treatment of solar lentigines.     

A case of ochronosis successfully treated with the picosecond laser

Exogenous ochronosis is a cutaneous condition characterized by blue‐black pigmentation resulting as a complication of long‐term application of skin‐lightening creams containing hydroquinone and other substances such as quinine, phenol and mercury derivatives. We report a case of a 55‐year‐old woman who developed exogenous ochronosis as a result of prolonged use of topical hydroquinone for 5 years, characterized by greyish hyperpigmented patches on the nose and cheeks. The diagnosis was confirmed histologically. Treatment with picosecond laser resulted in marked clinical improvement together with improvement in overall texture and quality of the skin.     

755 nm皮秒激光仪平光透镜与Focus蜂巢透镜联合应用治疗黄褐斑

目的：观察755 nm皮秒激光仪平光透镜与Focus蜂巢透镜联合应用治疗黄褐斑的临床疗效及不良反应。方法：对36例黄褐斑患者,联合应用755 nm皮秒激光仪平光透镜和Focus蜂巢透镜治疗,每4周治疗1次,6次为1个疗程。先用平光透镜对黄褐斑区域治疗1遍,能量密度0.4 J/cm2,光斑直径8 mm,频率5 Hz,后用Focus蜂巢透镜以同样参数再治疗1遍。治疗后随访12周。疗程结束后进行黄褐斑面积及严重程度指数（MASI）评分与患者自我满意度评价,记录不良反应,观察随访情况,并进行统计学分析。结果：治疗前、治疗6次后及治疗结束后12周MASI评分分别为（11.17±5.29）、 （4.63±3.05）、 （5.11±3.23）;治疗6次后MASI评分下降率为（64±7）%,治疗结束后12周为（61±6）%;治疗6次后与结束后12周的平均MASI评分均低于治疗前,差异有统计学意义（P＜0.05）;治疗结束后12周平均MASI评分比治疗6次后略有升高,但差异无统计学意义（P＞0.05）。Fitzpatrick III型皮肤患者MASI评分下降率为（68±8）%,高于IV型患者的（56±6）%,差异有统计学意义（P＜0.05）。治疗6次后患者满意率为94.4%,治疗结束后12周为88.9%。而且绝大多数患者皮肤肤质比治疗前更细腻紧致,细纹和毛孔粗大得到改善。所有患者均无明显不良反应发生。结论：755 nm皮秒激光仪平光透镜与Focus蜂巢透镜联合应用治疗黄褐斑起效快,不良反应少,复发率低,患者满意度高,是有效的治疗新方案。     

The Role of Stem Cell Factor in Hyperpigmented Skin Lesions

Background: Skin hyperpigmentation usually results from an increased number, or activity, of melanocytes. The degree of pigmentation of skin depends on the amount and type of melanin, degree of skin vascularity, presence of carotene, and thickness of the stratum corneum. Common causes of hyperpigmentation include post-inflammatory hyperpigmentation, melasma, solar lentigines, ephelides (freckles), and café-au-lait macules. Some skin tumors can be hyperpigmented as basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and malignant melanoma (MM). Stem cell factor (SCF) is a growth factor and its interaction with its receptor, c-kit, is well known to be critical to the survival of melanocytes. Methods: This study was carried out on 60 patients complaining of hyperpigmented skin lesions (20 melasma, 20 solar lentigines, and 20 freckles) and 36 patients with skin tumors (14 BCC, 12 SCC, and 10 MM). Punch skin biopsies were taken from the previous lesions. Immunohistochemical staining of these samples was done using the stem cell factor (SCF). Results: There was positive expression of SCF in all cases of melasma, solar lentigines and freckles with significant increase in the intensity of expression in the lesional areas than the non-lesional ones (P=0.004). There was also a statistically significant increase in the expression of SCF in BCC and melanoma tumor cells. Conclusion: SCF has a great role in skin hyperpigmented disorders and this can be used as a target for the developing of new antipigmentary lines of treatment by inhibiting SCF. SCF can also be involved in the emergence of some skin tumors.     

Treatment of hyperpigmentation

Hyperpigmentation is a common dermatologic condition that is seen in all skin types but is most prominent in skin of color. In skin of color, any inflammation or injury to skin can almost immediately be accompanied by alterations in pigmentation, either hyperpigmentation or hypopigmentation. Post-inflammatory hyperpigmentation can be observed in many skin conditions including acne, eczema, and contact dermatitis and treatment can be challenging. The goal is to reduce the hyperpigmentation without causing undesirable hypopigmentation or irritation in the surrounding area. This review will discuss current research on treatments for hyperpigmentation and approaches to treating this condition.     

黄褐斑动物模型的研究现状

黄褐斑作为一种黑色素沉着症,好发于中青年女性的面部,严重影响患者的身心健康。目前研究认为黄褐斑的发生与紫外线照射、体内性激素水平变化等多种因素有关,但其确切发病机制尚不清楚,其临床疗效多不理想,开展黄褐斑疾病相关的基础研究具有重要的临床意义和社会价值。其中,黄褐斑动物模型作为研究黄褐斑的重要工具,对于明确黄褐斑疾病发生、发展的病理生理学机制尤为重要,目前常用的造模方法有紫外线造模法、黄体酮造模法以及紫外线联合黄体酮造模法,但因黄褐斑动物模型在制备过程中的影响因素较多,且至今尚无较为完善且公认的模型制备方案,导致黄褐斑动物模型在实际应用过程中仍然存在一系列问题,降低了模型制备的成功率,在一定程度上影响和限制了模型的应用和推广。针对黄褐斑动物模型建立及应用过程中存在的关键性问题,通过查阅和整理近年来国内外的相关文献,从实验动物、建模方法、模型评价等方面综合概述该模型的研究现状,探讨不同造模方法以及动物品系、动物周龄等因素对黄褐斑动物模型的影响,以期为制备更科学合理、经济便捷的黄褐斑动物模型提供参考,为深入研究黄褐斑的发病机制、预防与治疗黄褐斑奠定基础,也为其他动物模型的研究提供借鉴和参考。