BACKGROUND: Androgenetic alopecia (AGA) is one of the most common alopecia among men and women worldwide. It is a nonscarring alopecia that has a characterized pattern. In female pattern AGA, the hairline is stable but general thinning occurs most notably in the frontal region. In male-pattern AGA, the hairline is receding and the thinning is most notable in the frontotemporal region. AGA has a complex pathogenesis and relation of subcutaneous fat in the scalp region and the miniaturization of terminal hair follicles is vague. In this study, subcutaneous fat in the frontal scalp an important region for AGA is compared to the occipital scalp that is spared in AGA.
METHODS: Our study is a cross-sectional study that has four groups. Male patient, female patient, male control, female control. Every group has 15 individuals. All of the people in the study are those referred to Rasoul Akram\'s dermatology clinic. The severity of alopecia is classified by Norwood scaling for male pattern AGA and Ludwig scaling for female pattern AGA. Subcutaneous tissue in the frontal and occipital regions is measured by ultrasonography. For evaluating the effect of aging on subcutaneous fat thickness, we subdivided any group into more than 40 years old and between 20 and 40 years old and compared these two subgroups.
RESULTS: The mean age of the three groups of male patient, female patient, and female control is 40 y/o and the mean age of male control is 41 y/o. The mean subcutaneous fat layer thickness in frontal region in male patients group is 6.0 mm (more than 40 y/o = 6.6 mm, between 20 and 40 y/o = 5.5 mm), in female patients group 5.1 mm (more than 40 y/o = 5.7 mm, between 20 and 40 y/o = 4.6 mm), in the male control group is 4.4 mm (more than 40 y/o = 4.7 mm, between 20 and 40 y/o = 4 mm) and in the female control group is 4.1 mm (more than 40 y/o = 4.5 mm, between 20 and 40 y/o = 3.6 mm). The mean subcutaneous fat layer thickness in the occipital region in the male patient\'s group is 6.4 mm (more than 40 y/o = 6.7 mm, between 20 and 40 y/o = 6 mm), in the female patient\'s group 6.1 mm (more than 40 y/o = 6.5 mm, between 20 and 40 y/o = 5.7 mm), in the male control group is 6.3 mm (more than 40 y/o = 6.8 mm, between 20 and 40 y/o = 5.7 mm) and in the female control group is 6.2 mm (more than 40 y/o = 6.6 mm, between 20 and 40 y/o = 5.8 mm).
CONCLUSIONS: This study demonstrates that the subcutaneous fat layer in the frontal region in both males and females is thicker in AGA patients than healthy group and the more severe the AGA, the thicker is subcutaneous layer in the frontal region. In the male patients group, the subcutaneous fat layer in the frontal region is thicker than in the female patients group but in the male and female control groups is not so different. The subcutaneous fat layer in the occipital region is thicker in older individuals in both patients and control groups but is not different when compared to AGA patients and control individuals.

BACKGROUND: Limited epidemiologic data has suggested direct associations between hair pigment, race, and incidence of alopecia areata (AA). Here, we examine the relationship between natural hair color, race, and the lifetime risk alopecia.
METHODS: In this case-control study, we included UK Biobank patients of all races and self-reported hair color with diagnoses of AA, androgenetic alopecia (AGA), or scarring alopecia (SA). Multivariable logistic regression was used to detect differences in lifetime risk.
RESULTS: Findings reveal a significantly increased risk of AA among individuals with black hair compared to dark brown hair (OR 1.71 [95% CI 1.22-2.38], p < 0.001). Those with red or blonde hair showed a decreased risk of AA (0.74 [0.56-0.97]; 0.62 [0.41-0.95], p < 0.05). No racial differences in AA prevalence were observed among individuals with black hair.
CONCLUSIONS: Darker hair colors may be associated with a higher risk of AA, lighter hair colors with a lower risk, and differences in hair color could contribute to previously noted racial variations in AA incidence, potentially influencing dermatologists\' perspectives on the disease\'s epidemiology.

Vitamin D is a crucial vitamin that participates in various biological processes through the Vitamin D Receptor (VDR). While there are studies suggesting that VDR might regulate hair growth through ligand-independent mechanisms, the efficacy of Vitamin D in treating hair loss disorders has also been reported. Here, through in vivo experiments in mice, in vitro organ culture of hair follicles, and cellular-level investigations, we demonstrate that 1,25-(OH)2D3 promotes mouse hair regeneration, prolongs the hair follicle anagen, and enhances the proliferation and migration capabilities of dermal papilla cells and outer root sheath keratinocytes in a VDR-dependent manner. Transcriptome analysis of VDR-knockout mouse skin reveals the involvement of HIF-1α, NLRP3, and IL-1β in these processes. Finally, we confirm that 1,25-(OH)2D3 can counteract the inhibitory effects of DHT on hair growth. These findings suggest that 1,25-(OH)2D3 has a positive impact on hair growth and may serve as a potential therapeutic agent for androgenetic alopecia (AGA).

OBJECTIVE: To investigate the relationship between homocysteine (HCY) and androgenetic alopecia (AGA).
METHODS: A case control study and two observational experiments on mice were conducted. In the first part, a total of 528 Chinese AGA patients and 500 age-matched healthy controls were included. Serum HCY levels of AGA and controls were compared. In the second part, eight mice were divided into two groups. Both groups of mice had their hair removed. AGA group received a DHT injection, and the other as control group. HCY levels in hair follicles (HFs) were detected by ELISA and compared. In the third part, twelve mice were divided into three groups and fed with different concentrations of methionine. After 4 weeks, serum HCY levels, parameters related to hair growth through observation and HE staining, and expression of immunohistochemistry (IHC) hair-growth-related markers Ki67, VEGF, IGF-1, Krt27, FGF9, and TGF-β1 were compared among the three groups.
RESULTS: In the first part, HCY levels were higher in AGA than the controls of both genders. However, there was no difference in HCY levels between groups with varying severity. Rates of hyperhomocysteinemia was higher in AGA patients than the controls. Logistic regression analysis showed serum HCY levels was positively correlated with the incidence of AGA. In the second part, HCY of the HFs in the AGA group was significantly higher than that in the control group. The third part showed that the increase in serum HCY levels inhibited the growth of mice hair, with the less expressed stimulative markers Ki67, VEGF, IGF-1, Krt27, and FGF9, while there was no difference in the expression of inhibitory markers TGF-β1.
CONCLUSIONS: There is a potential relationship between HCY and AGA. HCY had an inhibitory effect on hair growth. Further studies are necessary to explore the specific mechanism.

BACKGROUND: Ultraviolet (UV)-induced fluorescence technology is widely used in dermatology to identify microbial infections. Our clinical observations under an ultraviolet-induced fluorescent dermatoscope (UVFD) showed red fluorescence on the scalps of androgenetic alopecia (AGA) patients. In this study, based on the hypothesis that microbes are induced to emit red fluorescence under UV light, we aimed to explore the microbial disparities between the AGA fluorescent area (AF group) and AGA non-fluorescent area (ANF group).
METHODS: Scalp swab samples were collected from 36 AGA patients, including both fluorescent and non-fluorescent areas. The bacterial communities on the scalp were analyzed by 16S rRNA gene sequencing and bioinformatics analysis, as well as through microbial culture methods.
RESULTS: Significant variations were observed in microbial evenness, abundance composition, and functional predictions between fluorescent and non-fluorescent areas. Sequencing results highlighted significant differences in Cutibacterium abundance between these areas (34.06% and 21.36%, respectively; p < 0.05). Furthermore, cultured red fluorescent colonies primarily consisted of Cutibacterium spp., Cutibacterium acnes, Staphylococcus epidermidis, and Micrococcus spp.
CONCLUSIONS: This is the first study to investigate scalp red fluorescence, highlighting microbial composition variability across different scalp regions. These findings may provide novel insights into the microbiological mechanisms of AGA.

BACKGROUND: Hair transplant (HT) is the standard treatment for female pattern hair loss (FPHL), but scalp micropigmentation (SMP) is an alternative. Currently, there are no criteria to help choose between HT and SMP.
METHODS: Forty female patients with FPHL who had successfully undergone HT and SMP, were reviewed to identify factors that might help decide between treatments. Hair density (HD) and hair caliber were measured at the part line and mid-occipital region by a Folliscope. The sensitivity and specificity of HT and SMP were determined by area under the curve (AUC) and receiver operating characteristic curve.
RESULTS: Patients were divided into HT (n = 23) and SMP (n = 17) groups. The follicular unit density (FUD) (HT: 62.06 ± 4.8551/cm2; SMP: 66.59 ± 3.4971/cm2) and HD (HT: 96.16 ± 16.6954/cm2; SMP: 116.08 ± 17.0520/cm2) were significantly different (p < 0.01) between groups. The AUC for FUD was 77.6% with a cutoff value of 66.83 and 87.0% (1-0.412) sensitivity. The AUC for HD was 82.4% with a cutoff value of 96.17 and 69.6% (1-0.118) sensitivity.
CONCLUSIONS: HD was the most important factor when deciding between HT surgery and SMP. SMP is recommended when the HD is ≥104.6 hairs/cm2 and HT surgery is strongly recommended when the HD is ≤96.17 hairs/cm2.

The most common type of alopecia in women is female androgenetic alopecia (FAGA), characterized by progressive hair loss in a patterned distribution. Many oral therapies, including spironolactone (an aldosterone antagonist), androgen receptor blockers (e.g., flutamide/bicalutamide), 5-alpha-reductase inhibitors (e.g., finasteride/dutasteride), and oral contraceptives, target the mechanism of androgen conversion and binding to its respective receptor and therefore could be administered for the treatment of FAGA. Despite significant advances in the oral treatment of FAGA, its management in patients with a history of gynecological malignancies, the most common cancers in women worldwide, may still be a concern. In this review, we focus on the safety of antiandrogens for the treatment of FAGA patients. For this purpose, a targeted literature review was conducted on PubMed, utilizing the relevant search terms. To sum up, spironolactone seems to be safe for the systemic treatment of FAGA, even in high-risk populations. However, a general uncertainty remains regarding the safety of other medications in patients with a history of gynecologic malignancies, and further studies are needed to evaluate their long-term safety in patients with FAGA and risk factors to establish an optimal risk assessment and treatment selection protocol.

OBJECTIVE: The aim of this study is to systematically review randomized controlled clinical trials (RCTs) studying various types of regenerative medicine methods (such as platelet-rich plasma, stromal vascular fraction, cell therapy, conditioned media, etc.) in treating specific dermatologic diseases. Rejuvenation, scarring, wound healing, and other secondary conditions of skin damage were not investigated in this study.
METHODS: Major databases, including PubMed, Scopus, and Web of Science, were meticulously searched for RCTs up to January 2024, focusing on regenerative medicine interventions for specific dermatologic disorders (such as androgenetic alopecia, vitiligo, alopecia areata, etc.). Key data extracted encompassed participant characteristics and sample sizes, types of regenerative therapy, treatment efficacy, and adverse events.
RESULTS: In this systematic review, 64 studies involving a total of 2888 patients were examined. Women constituted 44.8% of the study population, while men made up 55.2% of the participants, with an average age of 27.64 years. The most frequently studied skin diseases were androgenetic alopecia (AGA) (45.3%) and vitiligo (31.2%). The most common regenerative methods investigated for these diseases were PRP and the transplantation of autologous epidermal melanocyte/keratinocyte cells, respectively. Studies reported up to 68.4% improvement in AGA and up to 71% improvement in vitiligo. Other diseases included in the review were alopecia areata, melasma, lichen sclerosus et atrophicus (LSA), inflammatory acne vulgaris, chronic telogen effluvium, erosive oral lichen planus, and dystrophic epidermolysis bullosa. Regenerative medicine was found to be an effective treatment option in all of these studies, along with other methods. The regenerative medicine techniques investigated in this study comprised the transplantation of autologous epidermal melanocyte/keratinocyte cells, isolated melanocyte transplantation, cell transplantation from hair follicle origins, melanocyte-keratinocyte suspension in PRP, conditioned media injection, a combination of PRP and basic fibroblast growth factor, intravenous injection of mesenchymal stem cells, concentrated growth factor, stromal vascular fraction (SVF), a combination of PRP and SVF, and preserving hair grafts in PRP.
CONCLUSIONS: Regenerative medicine holds promise as a treatment for specific dermatologic disorders. To validate our findings, it is recommended to conduct numerous clinical trials focusing on various skin conditions. In our study, we did not explore secondary skin lesions like scars or ulcers. Therefore, assessing the effectiveness of this treatment method for addressing these conditions would necessitate a separate study.

BACKGROUND: Oral finasteride and topical minoxidil formulations are the only FDA-approved drug therapies for androgenetic alopecia (AGA). Research into dutasteride, topical finasteride, and nontopical minoxidil (low-dose oral and sublingual) formulations in the treatment of AGA has spiked within recent years. Early findings show that these alternative drug therapies may have similar to improved efficacy and safety profiles relative to the conventional treatment options.
OBJECTIVE: Conducting a bibliometric analysis, compare trends in publications on these alternative drug therapies, identify key contributors, evaluate major findings from top-cited articles, and elucidate gaps in evidence.
METHODS: A search was conducted on the Web of Science database for publications on the use of alternative drug therapies in the treatment of AGA. A total of 95 publications, published between January 2003-March 2024, and their citation metadata were included in the analysis.
RESULTS: Dutasteride showed the greatest (n = 37) and longest (20+ years) history of publications, as well as the highest cumulative citations (n = 914); however, nontopical minoxidil showed a burst in research activity within the last 5 years (n = 33 publications since 2019). A relatively low number of randomized control trials (n = 3) for nontopical minoxidil suggests a need for higher-quality evidence.
CONCLUSIONS: Our analysis reveals major trends, contributors, and gaps in evidence for alternative drug therapies for AGA, which can help inform researchers on their future projects in this growing field of study. There is enthusiasm for exploring off-label formulations: nontopical forms of minoxidil (oral and sublingual), topical finasteride, and mesotherapy.

Androgenetic alopecia (AGA) is a prevalent cause of hair loss with complex pathophysiologic mechanisms that pose challenges for effective treatment. Despite various therapeutic approaches yielding only partial results, regenerative treatments, such as platelet-rich plasma (PRP), have gained popularity. However, the lack of standardized PRP practices, encompassing product preparation and application, has been a significant concern. This article aims to contribute to fill this gap by presenting a comprehensive overview of PRP practices at a large academic center. Through detailing our protocols, this work not only contributes to the understanding of AGA treatment but also emphasizes the crucial aspect of treatment standardization in the context of PRP therapy. By providing a practical representation of our institutional PRP practices, we aim to contribute to the ongoing discourse on refining and implementing standardized protocols, fostering reproducibility, and improving clinical outcomes in the management of AGA.