Department of Dermatology, Venereology and Andrology, Faculty of Medicine, Benha University, Benha, Egypt.
Pathology Department, Faculty of Medicine, Benha University, Benha, Egypt.
J Cosmet Dermatol. 2019 Jun;18(3):929-935. doi: 10.1111/jocd.12752. Epub 2018 Aug 19.
Chemical hair straightening becomes popular for managing frizzy hair. Keratin in hair care products can penetrate the cortex of the hair fiber improving the mechanical properties of damaged fibers and promote a surface coating that prevents or decreases water diffusion through the hair fibers. This may have beneficial effects on the hair structure; however, the side effects and safety of this treatment have not yet been completely evaluated.
To evaluate the efficacy and safety of chemical hair straightening application on the hair shaft.
Thirty female subjects older than 15 years with hair curl types III-V were included. They were subjected to full history taking and dermatologic examination of hair and scalp prior to and after application of chemical hair straightener. To detect the presence of transverse fissures, split ends, or possible side effects, the distal 3-5 cm of hair fibers were cut before and after the last step of chemical hair straightener application for light microscopy examination. Three randomly selected samples were examined by transmission electron microscope.
Chemical hair straightening led to significant decrease in the degree of hair curl and increased hair smoothness and shine. The treated hair fibers showed significant repair of the broken cuticle (P < 0.001), while no significant improvement was observed regarding transverse fissures or split ends (P 0.60 and 0.74, respectively).
Although chemical hair straightening application has a beneficial effect on hair shafts, some side effects may occur after. Hence, it is necessary to develop a more safe tool.
化学拉直头发因其能够打理卷发而受到欢迎。头发护理产品中的角蛋白可以渗透到头发纤维的皮质中，改善受损纤维的机械性能，并促进表面涂层的形成，防止或减少水分通过头发纤维扩散。这可能对头发结构有有益的影响；然而，这种治疗的副作用和安全性尚未得到完全评估。
评估化学拉直剂在头发上的应用效果和安全性。
纳入 30 名年龄在 15 岁以上、头发卷曲类型为 III-V 的女性受试者。在使用化学拉直剂之前和之后，对她们进行了完整的病史采集和头皮毛发检查。为了检测横向裂缝、发梢分叉或可能的副作用，在化学拉直剂最后一步应用前后，剪取头发纤维的远端 3-5 厘米进行光镜检查。随机选择 3 个样本进行透射电镜检查。
化学拉直导致头发卷曲程度显著降低，头发更加光滑有光泽。处理后的头发纤维显示出明显的修复（P < 0.001），而横向裂缝或发梢分叉则没有明显改善（P 值分别为 0.60 和 0.74）。
尽管化学拉直剂的应用对头发有有益的效果，但也可能会出现一些副作用。因此，有必要开发一种更安全的工具。
