Alopecia areata: Current understanding of the pathophysiology and update on therapeutic approaches, featuring the Japanese Dermatological Association guidelines

Type-2 immunity associated with type-1 related skin inflammatory diseases: friend or foe?

Chronic inflammatory skin diseases are multifactorial diseases that combine genetic predisposition, environmental triggers, and metabolic disturbances associated with abnormal immune responses. From an immunological perspective, the better understanding of their physiopathology has demonstrated a large complex network of immune cell subsets and related cytokines that interact with both epidermal and dermal cells. For example, in type-1-associated diseases such as alopecia areata, vitiligo, and localized scleroderma, recent evidence suggests the presence of a type-2 inflammation that is well known in atopic dermatitis. Whether this type-2 immune response has a protective or detrimental impact on the development and chronicity of these diseases remains to be fully elucidated, highlighting the need to better understand its involvement for the management of patients. This mini-review explores recent insights regarding the potential role of type-2-related immunity in alopecia areata, vitiligo, and localized scleroderma.

Reprofiling synthetic glucocorticoid-induced leucine zipper fusion peptide as a novel and effective hair growth promoter

Hair is a biofilament with unique multi-dimensional values. In human, in addition to physiologic impacts, hair loss and hair related disorders can affect characteristic features, emotions, and social behaviors. Despite significant advancement, there is a dire need to explore alternative novel therapies with higher efficacy, less side effects and lower cost to promote hair growth to treat hair deficiency. Glucocorticoid-induced leucine zipper (GILZ) is a protein rapidly induced by glucocorticoids. Studies from our group and many others have suggested that a synthetic form of GILZ, TAT-GILZ, a fusion peptide of trans-activator of transcription and GILZ, can function as a potent regulator of inflammatory responses, re-establishing and maintaining the homeostasis. In this study, we investigate whether TAT-GILZ could promote and contribute to hair growth. For our pre-clinical model, we used 9-12 week-old male BALB/c and nude (athymic, nu/J) mice. We applied TAT-GILZ and/or TAT (vehicle) intradermally to depilated/hairless mice. Direct observation, histological examination, and Immunofluorescence imaging were used to assess the effects and compare different treatments. In addition, we tested two current treatment for hair loss/growth, finasteride and minoxidil, for optimal evaluation of TAT-GILZ in a comparative fashion. Our results showed, for the first time, that synthetic TAT-GILZ peptide accelerated hair growth on depilated dorsal skin of BALB/c and induced hair on the skin of athymic mice where hair growth was not expected. In addition, TAT-GILZ was able to enhance hair follicle stem cells and re-established the homeostasis by increasing counter inflammatory signals including higher regulatory T cells and glucocorticoid receptors. In conclusion, our novel findings suggest that reprofiling synthetic TAT-GILZ peptide could promote hair growth by increasing hair follicle stem cells and re-establishing homeostasis.

Exploring the Role of Gut Microbiota in Patients with Alopecia Areata

Imbalances in gut microbiota reportedly contribute to the development of autoimmune diseases, but the association between the etiopathogenesis of alopecia areata (AA) and gut microbial dysbiosis remains unclear. This cross-sectional study was conducted to identify and compare the composition of the gut microbiome in patients affected by AA and those in a healthy control (HC) group, and to investigate possible bacterial biomarkers for the disease. Fecal samples were collected from 19 AA patients and 20 HCs to analyze the relationship with fecal bacteria. The three major genera constituting the gut microbiome of AA patients were Bacteroides, Blautia, and Faecalibacterium. The alpha diversity of the AA group was not statistically significant different from that of the HC group. However, bacterial community composition in the AA group was significantly different from that of HC group according to Jensen-Shannon dissimilarities. In patients with AA, we found an enriched presence of the genera Blautia and Eubacterium_g5 compared to the HC group (p < 0.05), whereas Bacteroides were less prevalent (p < 0.05). The gut microbiota of AA patients was distinct from those of the HC group. Our findings suggest a possible involvement of gut microbiota in in the as-yet-undefined pathogenesis of AA.

Patient-Reported Burden of Severe Alopecia Areata: First Results from the Multinational Alopecia Areata Unmet Need Survey

Purpose

Alopecia areata (AA) is an autoimmune disease characterized by hair loss that has significant psychosocial implications. This study aims to describe the patient-reported burden of severe AA, coping mechanism and information needs using data from the multinational AA Patient Satisfaction and Unmet Need Survey.

Patients and Methods

Participants with current or previous ≥50% scalp hair loss (n = 747) were recruited from 11 countries and completed a web-based survey that assessed demographics, clinical characteristics, disease burden and psychosocial impact. Data were stratified according to sex, current age, disease duration and current severity of scalp hair loss.

Results

The mean (SD) age of participants was 43.8 (7.1) years, 55.3% were women, and 63.5% reported AA symptoms within 6 months of diagnosis. Most participants had black or brown hair (88.4%), reported a disease duration of 2 years or more (75.6%) and had current scalp hair loss of ≥50% (87.4%). Severe hair loss also extended to eyebrow (46.9%), eyelash (48.7), beard (61.5%) and body hair (73.2%). Participants commonly reported comorbidities such as anxiety (26.1%), depression (18.1%) and sleep problems (28.1%). The Dermatology Life Quality Index revealed a severe impact on quality of life; 86.2% of participants scored >10. Mental health/mood was significantly affected; 55.8% of participants reported a substantial impact. Long-term effects included decreased self-esteem (32.9%), poor mental health (28.1%) and challenges in day-to-day activities (27.2%). Information needs were centered around treatment expectations, mental health, and available treatment options. More severe symptoms and a greater daily impact were reported by women and those with a longer disease duration.

Conclusion

The study emphasizes the substantial burden, including impaired quality of life and psychological well-being, of severe AA on the lives of surveyed participants. The findings highlight the importance of comprehensive disease management strategies that address both physical and psychosocial aspects of AA.

Baricitinib Therapy for Moderate to Severe Alopecia Areata: A Retrospective Review of 95 Japanese Patients

Abstract is missing (Short communication)

Degree of Alignment Between Japanese Patients and Physicians on Alopecia Areata Disease Severity and Treatment Satisfaction: A Real-World Survey

INTRODUCTION

Alopecia areata (AA) is characterized by non-scarring scalp and/or body hair loss and can negatively impact patient mental health. Data are limited on the alignment of patient and physician perceptions of AA severity with each other and with Japanese Dermatological Association (JDA) guideline criteria, and of patient-physician alignment on treatment satisfaction. Therefore, we performed analyses to compare JDA severity groupings with patient-physician alignment on disease severity and to explore treatment satisfaction in AA in Japan.

METHODS

Data were drawn from the Adelphi AA Disease Specific Programme (DSP)™, a real-world survey of physicians and patients with AA in Japan conducted January-March 2021. Patients and physicians reported patient AA severity as mild, moderate or severe based on their subjective judgement. Patients were then categorized into five hair loss severity groups according to JDA criteria (S1-5), and patient-physician pairs were matched to assess alignment on severity and treatment satisfaction.

RESULTS

Subjective patient- and physician-reported disease severity generally followed JDA severity groupings. The percentage of patient-physician alignment on severity recognition was 76.3% in the overall population. In misaligned pairs, 20.2%, 14.5%, 7.3%, 25.0% and 0.0% of physicians rated disease as more severe than patients in S1, S2, S3, S4 and S5, respectively. Regarding treatment satisfaction, patient-physician alignment was 57.6% in the overall population. In S5, 46.2% of physicians reported being less satisfied than patients. Both physicians and patients cited lack of efficacy as the main reason for dissatisfaction. Of 221 patients, 39.8% and 29.9% were categorized as borderline-abnormal cases for anxiety and depression, respectively.

CONCLUSIONS

This study highlights previously unreported patient-physician misalignment on disease severity, level of treatment dissatisfaction and unmet needs due to the lack of effective treatment. Further study on how improvement of the misalignment between physicians and patients could increase both patient and physician satisfaction with treatment and improve the quality of life for patients with AA.

Causal role of immune cells in alopecia areata: A two-sample Mendelian randomization study

BACKGROUND

Previous research has highlighted an association between alopecia areata (AA) and the collapse of hair follicle immune privilege, however, the causal linkage to specific immune cell traits remains to be elucidated. This study aimed to investigate the causal influence of immune cell traits on AA utilizing a two-sample Mendelian randomization (MR) approach.

METHODS

Leveraging GWAS summary statistics of 731 immunological traits (n = 3757) and AA data (n = 211,428), MR analyses were conducted employing inverse-variance weighted (IVW), weighted median, and MR-Egger regression methodologies. Sensitivity analyses were undertaken using Cochran's Q test, MR-Egger intercept test, and MR-PRESSO analysis. A reverse MR analysis was performed for immune cell traits identified in the initial MR analysis.

RESULTS

Our study unveiled multiple immune traits associated with AA. Protective associations were observed for CD62L- CD86+ myeloid dendritic cells (DCs), TD CD4+%CD4+ T cells, and others, with ORs ranging from 0.63 to 0.78. Conversely, traits like CD62L on CD62L+ plasmacytoid DCs, HLA-DR on CD14- CD16+ monocytes, HLA-DR on monocytes, and others, were determined to augment the risk of AA, with ORs ranging from 1.13 to 1.46. Reverse MR analysis signified a reduction in BAFF-R on IgD-CD24-B cells post-AA onset (OR: 0.97, 95% CI: 0.95-1.00), with no identified heterogeneity or horizontal pleiotropy among the instrumental variables (IVs).

CONCLUSIONS

Our findings suggests that CD62L on certain subpopulations of DCs and HLA-DR on monocytes may epitomize risk factors for AA, offering potential therapeutic targets for alleviating AA.

Treatments for Moderate-to-Severe Alopecia Areata: A Systematic Narrative Review

Treatments for alopecia areata (AA) have traditionally been prescribed off-label, and there has been no universal agreement on how to best manage the condition. Baricitinib is the first oral selective Janus kinase (JAK) inhibitor approved for the treatment of adults with severe AA. As a better understanding of the evidence supporting the management of AA in clinical practice is needed, we conducted a systematic literature review and subsequent narrative review to describe available evidence pertaining to the efficacy and tolerability of treatments currently recommended for adults with moderate-to-severe forms of AA. From 2557 identified records, a total of 53 records were retained for data extraction: 9 reported data from 7 randomized controlled trials (RCTs) versus placebo, and 44 reported data from unique RCTs with no placebo arm, non-randomized trials, or observational studies. Across drug classes, data were reported heterogeneously, with little consistency of data collection or clinical endpoints used. The most robust evidence was for the JAK inhibitor class, in particular the JAK1/JAK2 inhibitor baricitinib. Five RCTs (three for baricitinib) demonstrated a consistent benefit of JAK inhibitor therapy over placebo across various clinical outcomes in adult patients with at least 50% scalp hair loss. Overall, hair regrowth varied widely for the other drug classes and was generally low for patients with moderate-to-severe AA. Relapses were commonly observed during treatment and upon discontinuation. Adverse effects were generally consistent with the known safety profile of each intervention. The heterogeneity observed prevented the conduct of a network meta-analysis or an indirect comparison of different treatments. We found that the current management of patients with moderate-to-severe AA often relies on the use of treatments that have not been well evaluated in clinical trials. The most robust evidence identified supported the use of baricitinib, and other oral JAK inhibitors, in patients with severe AA.

Economic burden of alopecia areata: A study of direct and indirect cost in Japan using real-world data

Alopecia area (AA) is a common autoimmune disorder, characterized by hair loss. Although its impact on quality of life is fairly well understood, studies on the economic impact of AA are limited. The aim of this study was to quantify the personal and nationwide economic burden of AA in Japan. Data were drawn from the Adelphi AA Disease Specific Programme (DSP)™, a real-world, cross-sectional survey with retrospective data collection, of Japanese physicians and patients with AA. The study was conducted in 2021, before the approval of Janus kinase inhibitors for AA. Physicians and their consulting AA patients completed questionnaires regarding disease severity, treatment, and AA-related costs. The Work Productivity and Activity Impairment questionnaire was used to evaluate the impact of AA on patients' work and activity. Nationwide estimates of cost and productivity loss were extrapolated from collected patient data. A total of 50 physicians provided data on 235 patients; 58.7% were female, mean ± SD age was 41.1 ± 11.8 years, and mean physician-estimated scalp hair loss was 40.4% ± 30.2%. Prescription medication use was high (92.3% of patients), but the use of over-the-counter medication was low, at 8.7%. Mean cost to patients for medication was ¥ 4263 (US$ 32.42) per month. Productivity while at work (presenteeism) was significantly impaired (23.9% ± 25.7%), but absenteeism was low (0.9% ± 2.8%). The total nationwide cost of AA was estimated at 112.7 billion yen (US$ 857 million), of which 88.1 billion yen (78.2%) was due to productivity loss. Over 2 million days per year of activity time were estimated to be lost due to AA. Thus, despite not being a physically limiting disease, AA has a significant impact in terms of cost and time, both on a personal and national level. These data highlight the need for more targeted interventions to reduce the effects of AA on the Japanese economy.

Diagnosis and Management of Alopecia Areata: A Saudi Expert Consensus Statement (2023)

Alopecia areata (AA) is a complex autoimmune disease manifesting as a chronic inflammatory disease characterized by non-scarring patches of hair loss over the face, scalp, and body. Several treatments have been proposed for AA, but none are curative nor achieve a state of remission. The present consensus statement aims to present the evidence- and experience-based recommendations on the diagnosis and management of AA in Saudi Arabia. The Ministry of Health in Saudi Arabia has opted to initiate a meeting of a multidisciplinary group to discuss and concede on this topic. Eight dermatology experts and clinical pharmacists convened in eight consensus meetings. All content presented in this document was agreed upon by this working group, including diagnosis and severity assessment, prognostic indicators, and therapeutic options for AA. Special consideration was given to special patient populations including pediatric patients and patients with less frequent presentations of AA. Updates of the current recommendations will take place as new evidence evolves in the treatment of AA.

Clinical Findings, Response to Steroid Treatment, and Recurrence Rate in Alopecia Areata Patients with or without a Nonsynonymous Variant of Coiled-Coil Alpha-Helical Rod Protein 1

BACKGROUND

Alopecia areata (AA) is considered complex genetic and tissue-specific autoimmune disease. We recently discovered a nonsynonymous variant in the coiled-coil alpha-helical rod protein 1 (CCHCR1) gene within the AA risk haplotype. And a water avoidance stress test on CCHCR1 knockout mice induced AA-like lesions.

OBJECTIVE

To investigate the difference clinical findings of AA in patients with the CCHCR1 variant and without.

METHODS

We conducted a retrospective analysis of the data from 142 AA patients. Among these patients, 20 (14.1%) had a variant of CCHCR1. We evaluated the sex distribution of the patients, age at onset, distribution of the clinical types, prevalence of a positive family history of AA, prevalence of association of AA with atopic dermatitis, response to steroid therapy, and recurrence rate. We used multivariate logistic regression analysis and Fisher's exact test for statistical analysis. We also investigate electron microscopic observations of hair samples with the CCHCR1 variant and without.

RESULTS

The results showed a significant correlation between the CCHCR1 variant and the recurrence rate compared with the variant-negative group (p=0.0072). Electron microscopy revealed abnormalities in the hair shaft structure and hair cuticle in patients with the CCHCR1 variant (p=0.00174).

CONCLUSION

Our results suggest that AA with CCHCR1 variant is clinically characterized by a high recurrence rate and hair morphological abnormality.

IL-32 as a potential biomarker and therapeutic target in skin inflammation

IL-32 is a recently described cytokine that performs a variety of functions under inflammatory conditions. Serum IL-32 has been shown to be elevated in several diseases, including type 2 diabetes, cancer, systemic lupus erythematosus, HIV infection, and atopic diseases including atopic dermatitis. There are nine different isoforms of IL-32, with IL-32γ being the most biologically active one. The following review summarizes the different roles of the various IL-32 isoforms in the context of skin inflammation, with a focus on atopic dermatitis.

Clinical and Genetic Aspects of Alopecia Areata: A Cutting Edge Review

Alopecia areata (AA) is a chronic, non-scarring, immune-mediated skin disease that affects approximately 0.5-2% of the global population. The etiology of AA is complex and involves genetic and environmental factors, with significant advancements in genetic research occurring in recent years. In addition to well-known genes such as PTPN22, CTLA4, and IL2, which have been widely supported as being associated with AA, an increasing number of specific gene-related loci have been discovered through advances in genetic research. For instance, gene analysis of microRNAs can reveal the critical role of miRNAs in regulating gene expression, aiding in the understanding of cellular and organismal functional regulatory mechanisms. Furthermore, numerous studies have confirmed the existence of correlations between AA and other immune-related diseases. Examples include hyperthyroidism and rheumatoid arthritis. By understanding the interrelationships between AA and other immune diseases, we can further comprehend potential shared genetic foundations or pathogenic mechanisms among different diseases. Genetic research plays a crucial role in unraveling the pathogenesis of AA, as the identification of genetic variations associated with AA can assist in formulating more effective and targeted treatment strategies.

Trichoscopy pattern in alopecia areata: A systematic review and meta-analysis

BACKGROUND

The incidence of alopecia areata (AA) has increased over the last few decades. Trichoscopy is a noninvasive procedure performed in dermatology clinics and is a helpful tool in determining the correct diagnosis of hair loss presentations.

OBJECTIVE

Through mapping the researches that have been done to represent the spectrum of trichoscopic findings in AA and to identify the most characteristic patterns.

METHODS

Thirty-nine studies were eligible for the quantitative analysis. Meta-analysis and subgroup analysis were performed.

RESULTS

Thirty-nine studies (29 cross-sectional, five retrospective, two descriptive, one case series, one observational, and one cohort) with a total of 3204 patients were included. About 66.7% of the studies were from Asia, 25.6% from Europe, and 7.7% from Africa. The most characteristic trichoscopic findings of AA were as follows; yellow dots, black dots, broken hairs, short vellus hairs, and tapering hairs.

CONCLUSION

There is no single pathognomonic diagnostic trichoscopic finding in AA rather than a constellation of characteristic findings. The five most characteristic trichoscopic findings in AA are: yellow dots, black dots, broken hairs, short vellus hairs, and tapering hairs. Yellow dots and short vellus hairs considered the most sensitive clues for AA, while black dots and tapering hairs are the most specific ones. Furthermore, trichoscopy is a useful tool that allows monitoring of response during the treatment of AA. Treatment responded cases will show an increase in short vellus hairs, but loss of tapering hairs, broken hairs, and black dots, while yellow dots are the least responsive to the treatment.

Recent Advances in Understanding of the Etiopathogenesis, Diagnosis, and Management of Hair Loss Diseases

Hair-loss diseases comprise heterogenous conditions with respective pathophysiology and clinicopathological characteristics. Major breakthroughs in hair follicle biology and immunology have led to the elucidation of etiopathogenesis of non-scarring alopecia (e.g., alopecia areata, AA) and cicatricial alopecia (e.g., lichen planopilaris, LPP). High-throughput genetic analyses revealed molecular mechanism underlying the disease susceptibility of hair loss conditions, such as androgenetic alopecia (AGA) and female pattern hair loss (FPHL). Hair loss attracted public interest during the COVID-19 pandemic. The knowledge of hair loss diseases is robustly expanding and thus requires timely updates. In this review, the diagnostic and measurement methodologies applied to hair loss diseases are updated. Of note, novel criteria and classification/scoring systems published in the last decade are reviewed, highlighting their advantages over conventional ones. Emerging diagnostic techniques are itemized with clinical pearls enabling efficient utilization. Recent advances in understanding the etiopathogenesis and management for representative hair diseases, namely AGA, FPHL, AA, and major primary cicatricial alopecia, including LPP, are comprehensively summarized, focusing on causative factors, genetic predisposition, new disease entity, and novel therapeutic options. Lastly, the association between COVID-19 and hair loss is discussed to delineate telogen effluvium as the predominating pathomechanism accounting for this sequela.

Double mutation of claudin‐1 and claudin‐3 causes alopecia in infant mice

Hair follicles (HFs) undergo cyclic phases of growth, regression, and rest in association with hair shafts to maintain the hair coat. Nonsense mutations in the tight junction protein claudin (CLDN)-1 cause hair loss in humans. Therefore, we evaluated the roles of CLDNs in hair retention. Among the 27 CLDN family members, CLDN1, CLDN3, CLDN4, CLDN6, and CLDN7 were expressed in the inner bulge layer, isthmus, and sebaceous gland of murine HFs. Hair phenotypes were observed in Cldn1 weaker knockdown and Cldn3-knockout (Cldn1^Δ/Δ Cldn3^-/- ) mice. Although hair growth was normal, Cldn1^Δ/Δ Cldn3^-/- mice showed striking hair loss in the first telogen. Simultaneous deficiencies in CLDN1 and CLDN3 caused abnormalities in telogen HFs, such as an aberrantly layered architecture of epithelial cell sheets in bulges with multiple cell layers, mislocalization of bulges adjacent to sebaceous glands, and dilated hair canals. Along with the telogen HF abnormalities, which shortened the hair retention period, there was an enhanced proliferation of the epithelium surrounding HFs in Cldn1^Δ/Δ Cldn3^-/- mice, causing accelerated hair regrowth in adults. Our findings suggested that CLDN1 and CLDN3 may regulate hair retention in infant mice by maintaining the appropriate layered architecture of HFs, a deficiency of which can lead to alopecia.

Trichoscopy Pattern and Evaluation of Serum Vitamin D Status in Alopecia Areata

BACKGROUND

Vitamin D (VD) insufficiency has been linked to a number of autoimmune illnesses including, alopecia areata (AA). To distinguish between clinically common hair problems, trichoscopy is a beneficial non-invasive, rapid, and affordable procedure that is yet neglected.

OBJECTIVE

to evaluate trichoscopic patterns and severity in various clinical categories of AA considering vitamin D level (VDL). Also, focusing on specific patterns of trichoscopy in AA related to VDL.

SUBJECT AND METHODS

Severity of Alopecia Tool (SALT) was used to clinically assess patients with AA scores. Trichoscopic patterns were analyzed concerning VDL and disease severity. The VDL was estimated for 59 patients and 60 healthy controls.

RESULTS

VDL was higher in healthy controls than in AA patients. The most common trichoscopic findings seen in our study were yellow dots (77.97%), followed by black dots (67.8%), and broken hairs (59.32%). Short vellus hairs and yellow dots were the most common in remitting AA. In progressive AA, the most common findings were broken hairs, yellow dots, and tapering hairs. VDL was significantly higher in both mild and moderate AA.

CONCLUSIONS

VDL was significantly lower in severe AA and active progressive disease. Trichoscopic features could predict disease activity and VDL in patients with AA. Broken and tapering hairs will be more represented in patients with progressive disease. Short vellus hairs were seen more in stable or remitting disease. Furthermore, black dots and broken hairs were more prevalent in AA with deficient VDL.

Laser and light therapy combined with topical minoxidil for alopecia areata: a systematic review and meta-analysis of randomized controlled trials

We aim to evaluate the clinical efficacy and safety of using laser and light combined with topical minoxidil for alopecia areata. We searched PubMed, Embase, Web of Science, the Cochrane Library, China National Knowledge Infrastructure (CNKI), China Biomedical Literature Database (CBM), VIP database, and Wanfang Data from their inception to September 18, 2022. The risk of bias of the included RCTs was assessed by the Cochrane Collaboration tool. RevMan 5.3 software and Stata 14.0 software were used to perform the statistical analysis. The GRADE system assessed the quality of evidence. Ten studies were enrolled finally. The results of the meta-analysis showed that compared with topical minoxidil alone, the 308-nm excimer laser/light or He-Ne laser combined with topical minoxidil could reduce the SALT (Severity of Alopecia Tool) score (MD= -5.88, 95% CI [-9.79, -1.98], P=0.003). Whether fractional CO₂ laser (RR=1.29, 95% CI [1.14, 1.46], P<0.0001), 308-nm excimer laser/light (RR=1.32, 95% CI [1.12, 1.55], P=0.001), He-Ne laser (RR=1.69, 95% CI [1.07, 2.69], P=0.03), or NB-UVB (RR=1.35, 95% CI [1.07,1.70], P=0.01) combined with topical minoxidil may improve the treatment response rate, comparing with topical minoxidil only. The recurrence rate of laser and light combined with topical minoxidil was lower than that of the minoxidil alone group (RR=0.54, 95% CI [0.31, 0.93], P=0.03) when follow-up time was 1 year. In addition, the incidence of adverse events including irritant contact dermatitis, erythema, desquamation, pain, and pruritus was no significant difference between the two groups (RR=1.50, 95% CI [0.95, 2.36], P=0.08). The level of evidence for outcomes was classified as very low to moderate. Based on the available evidence, laser and light combined with topical minoxidil therapy may be effective and safe for alopecia areata. However, more high-quality trials are required for comprehensive analysis and further verification.

Hair Follicles as a Critical Model for Monitoring the Circadian Clock

Clock (circadian) genes are heterogeneously expressed in hair follicles (HFs). The genes can be modulated by both the central circadian system and some extrinsic factors, such as light and thyroid hormones. These circadian genes participate in the regulation of several physiological processes of HFs, including hair growth and pigmentation. On the other hand, because peripheral circadian genes are synchronized with the central clock, HFs could provide a noninvasive and practical method for monitoring and evaluating multiple circadian-rhythm-related conditions and disorders among humans, including day and night shifts, sleep-wake disorders, physical activities, energy metabolism, and aging. However, due to the complexity of circadian biology, understanding how intrinsic oscillation operates using peripheral tissues only may be insufficient. Combining HF sampling with multidimensional assays such as detection of body temperature, blood samples, or certain validated questionnaires may be helpful in improving HF applications. Thus, HFs can serve as a critical model for monitoring the circadian clock and can help provide an understanding of the potential mechanisms of circadian-rhythm-related conditions; furthermore, chronotherapy could support personalized treatment scheduling based on the gene expression profile expressed in HFs.

Pediatric androgenetic alopecia: an updated review

Pediatric androgenetic alopecia is an underrecognized disorder. A clinical evaluation with trichoscopy should be made in children and adolescents with hair loss and/or reduced hair density. Diagnosis is usually clinical, by observation of the hair loss pattern and performance of trichoscopy. In some cases, hyperandrogenism should be excluded. Although there is no approved therapy for androgenetic alopecia in pediatric age, topical minoxidil, oral minoxidil and topical finasteride may be very useful. Hair transplant may be an option for girls in selected cases. This article is a review of the current state of evidence concerning pediatric androgenetic alopecia.

Prevalence, comorbidities, and treatment patterns of Japanese patients with alopecia areata: A descriptive study using Japan medical data center claims database

Real-world data on alopecia areata (AA) demographics, comorbidities, and treatment patterns are sparse, not only in Japan but worldwide. This cross-sectional study assessed the current prevalence of AA in Japan, including analysis of severe subsets, frequency of comorbidities, and unmet medical needs surrounding treatment. Patients registered in the Japan Medical Data Center claims database (January 2012 to December 2019) and diagnosed with AA were included. Prevalence was calculated yearly, with the most common comorbidities evaluated, and treatments described in the Japanese Dermatological Association AA management guidelines and approved in Japan were included in the analysis. In total, 61 899 patients were diagnosed with AA. Among them, 1497 were diagnosed with severe subtypes. AA prevalence in Japan has been gradually increasing (from 0.16% in 2012 to 0.27% in 2019). The most common comorbidities are allergic rhinitis, atopic dermatitis, and asthma. Depression and anxiety are frequent in these patients, as are autoimmune diseases, e.g., vitiligo, thyroid diseases, and rheumatoid arthritis. Intriguingly, the analysis found Down syndrome to be a comorbidity associated with severe AA in children. The principal treatments were topical corticosteroids, followed by carpronium chloride and cepharanthine. The use of systemic corticosteroids and antihistamines is increased in severe disease. The Japanese Dermatological Association guidelines do not support the use of oral corticosteroids in children; however, in the database, this has been prescribed in up to 2.5% and 9.8% of all pediatric and severe pediatric AA cases, respectively. Despite the limitations of using a claims database, the current study demonstrates that AA prevalence in Japan has gradually increased in recent years, with allergic diseases being the most common comorbidities. The data also imply that there is a need for effective and safe therapies, especially for severe and pediatric cases.

Efficacy and safety of different JAK inhibitors in the treatment of alopecia areata: a network meta-analysis

Background

Alopecia areata (AA) is an immune disease characterized by non-scarring hair loss. With the widespread application of JAK inhibitors in immune-related diseases, attention is being given to their role in the treatment of AA. However, it is unclear which JAK inhibitors have a satisfactory or positive effect on AA. This network meta-analysis aimed to compare the efficacy and safety of different JAK inhibitors in the treatment of AA.

Methods

The network meta-analysis was performed according to the PRISMA guidelines. We included randomized controlled trials as well as a small number of cohort studies. The differences in efficacy and safety between the treatment and control groups were compared.

Results

Five randomized controlled trials, two retrospective studies, and two prospective studies involving 1689 patients were included in this network meta-analysis. In terms of efficacy, oral baricitinib and ruxolitinib significantly improved the response rate of patients compared to placebo [MD = 8.44, 95% CI (3.63, 19.63)] and [MD = 6.94, 95% CI, (1.72, 28.05)],respectively. Oral baricitinib treatment significantly improved the response rate compared to non-oral JAK inhibitor treatment [MD=7.56, 95% CI (1.32,43.36)]. Oral baricitinib, tofacitinib, and ruxolitinib treatments significantly improved the complete response rate compared to placebo [MD = 12.21, 95% CI (3.41, 43.79)], [MD = 10.16, 95% CI (1.02, 101.54)], and [MD = 9.79, 95% CI, (1.29, 74.27)], respectively. In terms of safety, oral baricitinib, tofacitinib, and ruxolitinib treatments significantly reduced treatment-emergent adverse event rates compared with conventional steroid treatment [MD = 0.08, 95% CI (0.02, 0.42)], [MD = 0.14, 95% CI (0.04, 0.55)], and [MD = 0.35, 95% CI, (0.14, 0.88)], respectively.

Conclusion

Oral baricitinib and ruxolitinib are excellent options for the treatment of AA owing to their good efficacy and safety profiles. In contrast, non-oral JAK inhibitors do not appear to have satisfactory efficacy in treating AA. However, further studies are required to verify the optimal dose of JAK inhibitors for AA therapy.

Dupilumab for alopecia areata treatment: A double-edged sword?

Alopecia areata (AA), which is a common and inflammatory hair loss and one of the most frequent dermatological conditions with higher incidence worldwide, the complex interplay involved multiple factors was contributed to the pathogenesis that consists of immune privilege losing and destruction with autoimmune-mediated in hair follicle also the abnormal regulation of inflammatory pathways was highlighted, although it was remained unclear to date.(J Am Acad Dermatol, 78, 2018, 1) Some treatment options for AA were proposed with great advances in recent years, but the options and efficacy were limited, such as platelet-rich plasma, JAK-STAT inhibitor, PDE4 inhibitor, and others, also the good response with regrow hair of cytokine-targeted therapy like dupilumab, ustekinumab was shown.(Clin Exp Med, 21, 2021, 215; Drugs, 80, 2020, 635) Here, we present a case with onset of AA following dupilumab treatment, the chronological relationship between the AA onset and dupilumab use should be known and emphasized.

How Our Microbiome Influences the Pathogenesis of Alopecia Areata

Alopecia areata is a multifactorial autoimmune-based disease with a complex pathogenesis. As in all autoimmune diseases, genetic predisposition is key. The collapse of the immune privilege of the hair follicle leading to scalp loss is a major pathogenic event in alopecia areata. The microbiota considered a bacterial ecosystem located in a specific area of the human body could somehow influence the pathogenesis of alopecia areata, as it occurs in other autoimmune diseases. Moreover, the Next Generation Sequencing of the 16S rRNA bacterial gene and the metagenomic methodology have provided an excellent characterization of the microbiota. The aim of this narrative review is to examine the published literature on the cutaneous and intestinal microbiota in alopecia areata to be able to establish a pathogenic link. In this review, we summarize the influence of the microbiota on the development of alopecia areata. We first introduce the general pathogenic mechanisms that cause alopecia areata to understand the influence that the microbiota may exert and then we summarize the studies that have been carried out on what type of gut and skin microbiota is found in patients with this disease.

Targeting mitochondria in dermatological therapy: Beyond oxidative damage and skin aging

INTRODUCTION

The analysis of the role of the mitochondria in oxidative damage and skin aging is a significant aspect of dermatological research. Mitochondria generate most reactive oxygen species (ROS); however, excessive ROS are cytotoxic and DNA-damaging and promote (photo-)aging. ROS also possesses key physiological and regulatory functions and mitochondrial dysfunction is prominent in several skin diseases including skin cancers. Although many standard dermatotherapeutics modulate mitochondrial function, dermatological therapy rarely targets the mitochondria. Accordingly, there is a rationale for "mitochondrial dermatology"-based approaches to be applied to therapeutic research.

AREAS COVERED

This paper examines the functions of mitochondria in cutaneous physiology beyond energy (ATP) and ROS production. Keratinocyte differentiation and epidermal barrier maintenance, appendage morphogenesis and homeostasis, photoaging and skin cancer are considered. Based on related PubMed search results, the paper evaluates thyroid hormones, glucocorticoids, Vitamin D3 derivatives, retinoids, cannabinoid receptor agonists, PPARγ agonists, thyrotropin, and thyrotropin-releasing hormone as instructive lead compounds. Moreover, the mitochondrial protein MPZL3 as a promising new drug target for future "mitochondrial dermatology" is highlighted.

EXPERT OPINION

Future dermatological therapeutic research should have a mitochondrial medicine emphasis. Focusing on selected lead agents, protein targets, in silico drug design, and model diseases will fertilize a mito-centric approach.

Lifestyle Factors Involved in the Pathogenesis of Alopecia Areata

Alopecia areata is a representative inflammatory skin disease that is associated with various environmental stimuli. While psychological stress is believed to be a major pathogenetic trigger in alopecia areata, infants and newborns also suffer from the disease, suggesting the possible presence of other environmental factors. Daily lifestyle is well known to be involved in various inflammatory diseases and influences the severity of inflammatory skin diseases. However, only a limited number of studies have summarized these influences on alopecia areata. In this review article, we summarize lifestyle factor-related influences on the pathogenesis of alopecia areata and focus on environmental factors, such as smoking, alcohol consumption, sleep, obesity, fatty acids, and gluten consumption.