Ultraviolet exposure may promote the development of androgenetic alopecia. On the one hand, ultraviolet irradiation can cause perifollicular inflammation through oxidative stress and microecological changes, and can also induce keratinocytes, melanocytes and mast cells to participate in the development of follicular microinflammation; on the other hand, ultraviolet irradiation can cause the aging of hair follicle stem cells, dermal papilla cells and dermal fibroblasts, as well as the increase of elastic fibers. This review summarizes relevant literature in recent years, in order to provide a theoretical basis for advocating protection of the hair and scalp against sunlight to prevent androgenetic alopecia.

The main pathological feature of androgenetic alopecia is the progressive miniaturization of hair follicles, which is closely related to vascular changes around hair follicles. Vascular endothelial growth factor interacts with dermal papilla cells and hair follicle stem cells to promote the formation of blood vessels around hair follicles, and to increase the nutrient supply to hair follicles, thereby promoting hair growth. This review summarizes research progress in the role of vascular endothelial growth factor in androgenetic alopecia.

Autophagy is the essential mechanism for cell adaptation and survival. Under normal physiological conditions, autophagy activates hair follicle stem cells, induces the transition of hair follicles from the telogen phase to the anagen phase, and maintains the hair growth cycle. Moreover, autophagy can protect dermal papilla cells from damage under pathological conditions. Intervention in autophagy can slow the progress of hair loss due to the existence of impaired autophagy in androgenetic alopecia and alopecia areata. The review summarizes the role of autophagy in hair cycle regulation, cell homeostasis maintenance, and hair regeneration, providing new insights into therapeutic options targeting follicular autophagy signaling pathways.

Vitiligo is a common acquired depigmentation skin disease involving the skin and hair, which is caused by the loss of function or reduction in the number of epidermal melanocytes and hair follicle melanocytes. The main principle of treatment is to control the disease progression, promote the repigmentation in lesional areas, and achieve morphological and functional repair. Skin and hair follicle melanocytes are the main source of vitiligo repigmentation, and thus transplantation of the whole tissues or tissue-derived cell suspensions to the vitiligo lesions is often used for the treatment of vitiligo. This review summarizes the progress in the application of hair follicle transplantation and follicular cell suspension transplantation in the surgical treatment of vitiligo.

Autophagy is the essential mechanism for cell adaptation and survival. Under normal physiological conditions, autophagy activates hair follicle stem cells, induces the transition of hair follicles from the telogen phase to the anagen phase, and maintains the hair growth cycle. Moreover, autophagy can protect dermal papilla cells from damage under pathological conditions. Intervention in autophagy can slow the progress of hair loss due to the existence of impaired autophagy in androgenetic alopecia and alopecia areata. The review summarizes the role of autophagy in hair cycle regulation, cell homeostasis maintenance, and hair regeneration, providing new insights into therapeutic options targeting follicular autophagy signaling pathways.

Vitiligo is a common acquired depigmentation skin disease involving the skin and hair, which is caused by the loss of function or reduction in the number of epidermal melanocytes and hair follicle melanocytes. The main principle of treatment is to control the disease progression, promote the repigmentation in lesional areas, and achieve morphological and functional repair. Skin and hair follicle melanocytes are the main source of vitiligo repigmentation, and thus transplantation of the whole tissues or tissue-derived cell suspensions to the vitiligo lesions is often used for the treatment of vitiligo. This review summarizes the progress in the application of hair follicle transplantation and follicular cell suspension transplantation in the surgical treatment of vitiligo.

Ultraviolet exposure may promote the development of androgenetic alopecia. On the one hand, ultraviolet irradiation can cause perifollicular inflammation through oxidative stress and microecological changes, and can also induce keratinocytes, melanocytes and mast cells to participate in the development of follicular microinflammation; on the other hand, ultraviolet irradiation can cause the aging of hair follicle stem cells, dermal papilla cells and dermal fibroblasts, as well as the increase of elastic fibers. This review summarizes relevant literature in recent years, in order to provide a theoretical basis for advocating protection of the hair and scalp against sunlight to prevent androgenetic alopecia.

The main pathological feature of androgenetic alopecia is the progressive miniaturization of hair follicles, which is closely related to vascular changes around hair follicles. Vascular endothelial growth factor interacts with dermal papilla cells and hair follicle stem cells to promote the formation of blood vessels around hair follicles, and to increase the nutrient supply to hair follicles, thereby promoting hair growth. This review summarizes research progress in the role of vascular endothelial growth factor in androgenetic alopecia.

Objective:To investigate the clinical efficacy of bilateral V-Y advancement island flaps on buttocks in repairing postoperative defects in patients with perianal Paget′s disease.Methods:From January 2009 to January 2021, a retrospective analysis was performed on clinical data collected from 13 patients with perianal Paget′s disease, whose perianal defects resulting from the tumor resection were reconstructed with bilateral V-Y advancement island flaps on the buttocks in the Department of Dermatology, Hangzhou Third People′s Hospital. The postoperative recovery of the buttocks and the effects on the defecation function were evaluated.Results:The areas of perianal defects in 13 cases ranged from 4.8 cm × 5.6 cm to 12.2 cm × 6.4 cm. All defects were successfully repaired by using the bilateral V-Y advancement island flaps, and all surgical wounds healed primarily. One case first received temporary ileostomy, and then received ileostomy closure 3 months later, resulting in the recovery of defecation function; in another 1 case of perianal Paget′s disease comorbid with rectal cancer, the permanent sigmoid colostomy was performed to divert feces, and the defecation function was lost. After the follow-up for 1 - 6 years, the buttocks were symmetrical in shape in all the 13 patients, and 12 with preserved anus had normal defecation function. No tumor recurrence was observed in 12 patients without other malignant tumors after the operation, while 3 patients experienced mild anal stenosis without anal mucosa eversion or wound dehiscence; 1 patient with perianal Paget′s disease complicated by anal canal adenocarcinoma developed bilateral inguinal lymph node and internal iliac lymph node metastasis 1 year after the operation, and died 6 months later.Conclusion:The bilateral V-Y advancement island flaps on the buttocks have the advantages of reliable blood supply and sufficient advancement mobility, and can be used to repair large skin defects around the anus.

Objective:To analyze the clinical efficacy of electrolysis of depigmented hair using a trichiasis electrolyzer combined with hair follicle transplantation in the treatment of vitiligo-associated leukotrichia.Methods:Clinical data were retrospectively collected from 25 patients with stable vitiligo-associated leukotrichia in the Department of Dermatologic Surgery, Hangzhou Third People′s Hospital from January 2019 to January 2021. All the patients received electrolysis of depigmented hair using a trichiasis electrolyzer combined with hair follicle transplantation. Outpatient follow-up visits were conducted in the first week, as well as the first, third and sixth months after surgery. The texture and growth status of transplanted hair were observed, and the survival rate of transplanted hair follicles and the proportion of newborn white hair in white hair in the original lesions were recorded.Results:Among the 25 patients with stable vitiligo, there were 14 males and 11 females, and their disease duration ranged from 2 to 15 years, with the average duration being 5.8 years. A total of 30 white patches accompanied by leukotrichia were included, including 9 on the scalp, 7 on the eyebrows and 14 on the eyelashes. One week after surgery, the transplanted hair survived well in all patients, without obvious shedding or local infection. Six months after surgery, repigmentation was observed in most hair in the original lesion area, and only a small amount of white hair grew out, without obvious scarring; the survival rate of transplanted hair follicles was 76.5% ± 10.0%, and the proportion of newborn white hair in white hair in the original lesions was 16.7% ± 7.8%.Conclusion:Electrolysis of depigmented hair using a trichiasis electrolyzer combined with hair follicle transplantation was effective in the treatment of vitiligo-associated leukotrichia, with a simple treatment process and few postoperative complications, which provided a reliable choice for the clinical treatment of vitiligo-associated leukotrichia.