Lifestyle Factors Involved in the Pathogenesis of Alopecia Areata

Alopecia Areata: Pathogenesis, Diagnosis, and Therapies

Alopecia areata (AA) is a complex, chronic inflammatory skin disorder characterized by unpredictable, nonscarring hair loss, affecting millions worldwide. Its pathogenesis remains poorly understood, driven by intricate interactions among immune dysregulation, genetic predisposition, and environmental triggers. Despite significant advances in identifying these contributing factors, substantial gaps persist in our understanding of the full spectrum of AA's molecular mechanisms and in the development of effective therapeutic approaches. This review aims to comprehensively explore the immunological, genetic, epigenetic, and environmental factors underlying AA, with a focus on immune-mediated mechanisms. We also evaluate diagnostic approaches and recent advancements in assessing disease severity. Furthermore, the review discusses evolving therapeutic options, including traditional therapies, biologics, small-molecule agents, and emerging treatments. The academic value of this work lies in its synthesis of current knowledge on the multifaceted nature of AA, providing insights for future research and clinical practice. By elucidating the interconnected factors underlying AA, this review seeks to advance both understanding and management of this prevalent, clinically challenging disorder.

Exosomes from human umbilical cord mesenchymal stem cells promote the growth of human hair dermal papilla cells

Human hair dermal papilla cells (HHDPCs) play a significant role in hair growth. This study found that human umbilical cord mesenchymal stem cell-derived exosomes (UC-MSC-Es) effectively enhanced cell growth of HHDPCs. UC-MSC-Es has a size range of 30-180 nm and expression of CD9, CD63, CD81, CD73, and TSG101. UC-MSC-Es significantly increased cell populations of HHDPCs in the S and G2/M phases. UC-MSC-Es also increased the expression of cell cycle-related proteins, β-catenin, and cyclin D1. Further mechanistic studies demonstrated that UC-MSC-Es promoted the phosphorylation of Akt and GSK-3β, and the inhibition of PI3K and Akt reduced the proliferative effects of UC-MSC-Es. Collectively, these findings suggest that UC-MSC-Es have a potential effect in treating hair loss through modulating PI3K and Akt-dependent pathways in HHDPCs.

Sexual Dysfunction in Alopecia Areata: A Systematic Review

Background: Alopecia areata (AA) contributes to clinically significant suffering, and impaired social functioning. Among AA patients, there is a clear impact of the disease on their sense of attractiveness and desirability as sexual partners. This review explores the development of sexual disorders among AA patients, highlighting their importance in the clinical diagnosis of comorbid health disorders with hair loss. Methods: A systematic review was conducted by searching electronic databases, including MEDLINE and Google Scholar, without date limitations, according to the PRISMA guidelines. Key search terms included "sexuality" or "sexual health" or "sexual dysfunction" or "sexual disorder" AND "alopecia areata". Data synthesis included findings from eight relevant studies. Results: Hair loss in the course of AA has a negative impact on the sexual sphere, significantly reducing the quality of life of patients and their partners. Proper sexual functioning is an integral part of every person, so special attention should be paid to the possibility of developing sexual dysfunction in the course of AA. Conclusions: Small sample sizes and heterogeneous populations make it difficult to draw firm conclusions. Continued research with standardized criteria for SD diagnosis and appropriately large cohorts will be essential to fully establish psychosexual disorders among AA patients.

Potential Causal Relationship Between Extensive Lipid Profiles and Various Hair Loss Diseases: Evidence From Univariable and Multivariable Mendelian Randomization Analyses

BACKGROUND

Hair loss disorders, including non-cicatricial forms such as alopecia areata (AA) and androgenetic alopecia (AGA), as well as cicatricial forms, represent significant dermatological concerns influenced by various factors, including lipid metabolism. While observational studies and clinical trials have suggested a link between lipid levels and hair loss, the causal relationship remains unclear.

METHODS

We conducted a comprehensive analysis of 983 lipid variables [including triglycerides (TG), fatty acids, cholesterol, cholesterol esters, phospholipids, and lipoproteins] and 4 hair loss disorders. Two-sample univariable Mendelian randomization (UVMR) and multivariable Mendelian randomization (MVMR) analyses were employed to investigate the causal effects of lipids on hair loss disorders. Sensitivity analyses were performed to ensure the robustness of our findings.

RESULTS

The UVMR analysis identified 56 significant causal associations between lipid levels and hair loss disorders, with cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), TG, apolipoprotein A1, apolipoprotein B, and lipoprotein(a) emerging as key contributors. The MVMR analysis evaluated the independent effects of HDL-C, LDL-C, and TG on alopecia disorders, identifying significant associations only between HDL-C, TG, and AA. Sensitivity analyses confirmed the consistency and robustness of these results.

CONCLUSION

This study provides strong evidence for potential causal associations between lipids and hair loss disorders, highlighting potential therapeutic targets and the importance of lipid management in affected patients.

Total glucosides of paeony inhibit NLRP3/caspase-1/GSDMD-mediated inflammation and pyroptosis in C3H/HeJ mice with alopecia areata

One of the most prominent causes of alopecia areata (AA) is chronic inflammation of the hair follicles. Inhibiting cellular pyroptosis, a form of inflammatory programmed cell death, is crucial for reducing follicular inflammation in the skin. Total glucosides of paeony (TGP) possess anti-inflammatory properties across a broad range of illnesses. However, the role of TGP in AA and its relationship to pyroptosis remain unclear. A chronic unpredictable mild stress (CUMS) approach was used to create an AA mouse model. TGP suspension and MCC950 were administered to AA mice via gavage. HE staining, ELISA, immunohistochemistry, immunofluorescence, RT-qPCR, and Western blotting were performed to detect pathological changes in the skin and investigate the levels of inflammatory factors and pyroptosis-related proteins, as well as the potential mechanisms of TGP's effects. TGP reduced hair loss, increased the number of hair follicles in skin tissues, and decreased inflammatory markers (IL-6, TNF-α, IL-18, and IL-1β) in AA mice. MCC950 significantly reduced the levels of NLRP3/caspase-1/Gasdermin D (GSDMD)-mediated pyroptosis-related proteins (NLRP3, ASC, caspase-1 p10, and GSDMD-N), as well as inflammatory factors. TGP markedly inhibited NLRP3/caspase-1/GSDMD-mediated cellular pyroptosis in a concentration-dependent manner. TGP suppresses the NLRP3/caspase-1/GSDMD signaling cascade in the skin tissues of AA mice, thereby reducing cellular pyroptosis and inflammation. TGP may be a potential therapeutic agent for AA.

Alopecia Areata Is Associated with an Increased Risk for Prediabetes and Obesity: A Nationwide Case-Control Study

Background and Aims: Alopecia areata (AA) is a non-scarring inflammatory hair loss condition associated with various immune-mediated comorbidities. Prediabetes, characterized by elevated blood glucose levels not yet high enough to be classified as diabetes, significantly increases the risk of developing type 2 diabetes mellitus (T2DM) and cardiovascular complications. The associations between AA obesity and prediabetes have long been investigated in an attempt to identify preventable risk factors, yet the literature is relatively scarce and inconclusive. This study aimed to explore the association between AA, prediabetes, obesity, and T2DM in a large population cohort. Methods: All patients diagnosed with AA between 2005 and 2019 within Maccabi Healthcare Services (MHS) in Israel were compared with age-matched and gender-matched healthy controls for prediabetes, T2DM and obesity, using logistic regression models for all analyses. A total of 33,401 patients with AA and 66,802 controls were included in the analysis. Results: The prevalence of prediabetes was significantly higher in AA patients (26.3%) compared to controls (18.1%), with an odds ratio (OR) of 1.62. Obesity prevalence was also higher in AA patients (17.2% vs. 13.3%, OR 1.35). T2DM prevalence was similar between groups. Prediabetes prevalence notably increased with age in AA patients, especially in those aged 40 and older (OR 2.02). Discussion: The study highlights a significant association between prediabetes and alopecia areata, with prediabetes risk emerging prominently in AA patients. Obesity also showed a strong link with AA. These findings suggest the need for regular screening and early management of prediabetes and obesity in patients with AA to potentially mitigate associated health risks.

Alopecia Areata: Understanding the Pathophysiology and Advancements in Treatment Modalities

Alopecia areata (AA) is an autoimmune condition that presents with non-scarring hair loss affecting multiple patients worldwide during their lifetime. It ranges from well-defined patchy to diffuse total hair loss, impacting all hair-bearing areas of the body. AA most commonly predominantly manifests on the scalp. The pathophysiology of AA is complex and multi-faceted. The findings of our review article were consistent with the recent literature, delineating autoimmunity, genetic susceptibility, and environmental aspects to be the contributing factors. One of the main causes of AA is believed to be the disruption in the immune privilege of the hair follicles. Multiple genetic loci involved in hair follicle maturation and immune process have been linked to the development of AA as evidenced by several studies. It has been postulated that psychological stressors, smoking, alcohol consumption, sleep disturbances, gut microbiota, and drugs play a role in the pathogenesis of AA by exacerbating the immune response against the hair follicles. AA is a clinically diagnosed disorder. Topical, intra-lesional, and oral corticosteroids, topical and oral minoxidil, cyclosporine, and other immune therapy drugs are widely accepted first-line treatment options, although incomplete remission and relapses are common. Recently JAK-2 inhibitors and mesenchymal stem cell exosomes have shown promising results, potentially treating severe and refractory hair loss. AA has a bidirectional relationship with psychological symptoms as it can lead to social anxiety and depression, which in turn can aggravate hair loss. Hence, it is crucial to implement a holistic approach to managing AA including topical and systemic therapies, psychological counseling, and lifestyle modifications. It is imperative to fully declinate the pathophysiological mechanisms of the disease and formulate therapies in future research to help clinicians and dermatologists devise definitive guidelines to treat the condition for long-term remission.

Alopecia Areata Is Associated with Posttraumatic Stress Disorder and Alcohol Use in a Case-Control Study of 4,785 Patients

Introduction

Previous studies have demonstrated association of alopecia areata (AA) with anxiety and depression. However, few case-control studies have evaluated AA association with posttraumatic stress disorder and lifestyle factors, including alcohol use. We aimed to assess associations of AA with psychiatric disorders and lifestyle factors using a national database.

Methods

A nested case-control study using the National Institutes of Health All of Us database was conducted analyzing patients ≥18 years with AA diagnosis and controls matched 1:4 by age, sex at birth, and self-reported ethnicity/race.

Results

There were 957 AA patients and 3,828 controls included in the final analysis. AA patients versus controls had higher odds of depression, posttraumatic stress disorder, anxiety, and alcohol use. AA patients had decreased odds of smoking.

Conclusion

Our study demonstrates previously understudied AA associations with posttraumatic stress disorder, obesity, and alcohol use, and corroborates high burden of anxiety and depression among AA patients. We recommend screening AA patients for psychiatric disorders and alcohol use and appropriate referrals to psychiatry.

Innovative strategies for the discovery of new drugs against alopecia areata: taking aim at the immune system

INTRODUCTION

The autoimmune hair loss condition alopecia areata (AA) exacts a substantial psychological and socioeconomic toll on patients. Biotechnology companies, dermatology clinics, and research institutions are dedicated to understanding AA pathogenesis and developing new therapeutic approaches. Despite recent efforts, many knowledge gaps persist, and multiple treatment development avenues remain unexplored.

AREAS COVERED

This review summarizes key AA disease mechanisms, current therapeutic methods, and emerging treatments, including Janus Kinase (JAK) inhibitors. The authors determine that innovative drug discovery strategies for AA are still needed due to continued unmet medical needs and the limited efficacy of current and emerging therapeutics. For prospective AA treatment developers, the authors identify the pre-clinical disease models available, their advantages, and limitations. Further, they outline treatment development opportunities that remain largely unmapped.

EXPERT OPINION

While recent advancements in AA therapeutics are promising, challenges remain, including the lack of consistent treatment efficacy, long-term use and safety issues, drug costs, and patient compliance. Future drug development research should focus on patient stratification utilizing robust biomarkers of AA disease activity and improved quantification of treatment response. Investigating superior modes of drug application and developing combination therapies may further improve outcomes. Spirited innovation will be needed to advance more effective treatments for AA.

Changes and significance of Th1/Th2 and Treg/Th17 cells and their cytokines in patients with alopecia areata

BACKGROUND

Alopecia areata (AA) is a chronic autoimmune disease. Th1/Th2 and Treg/Th17 cells and their cytokines are implicated in AA, and we explored their clinical significance in AA.

METHODS

AA patients and healthy people (controls) were enrolled, with their Th1/Th2/Th17/Treg cell proportion changes and serum Th1 (INF-γ)/Th2 (IL-5, IL-6)/Th17 (IL-17, IL-22)/Treg (IL-35) cytokine levels assessed. AA patients were assigned into mild, moderate and severe alopecia according to Severity of Alopecia Tool (SALT). The relationship between alopecia severity and initial onset age, disease course, family/smoking/drinking history and sleep disorders was explored. Th1/Th2 and Treg/Th17 cells and their cytokine levels in AA patients with different severity levels were compared. The correlation between cytokine levels and SALT scores was analyzed using Spearman. Additionally, the changes of serum cytokine levels in inactive/active AA patients were compared.

RESULTS

AA patients differed from controls in family history/smoking history/drinking history/sleep disorders. Peripheral blood Th1/Th2/Th17 cell proportions and INF-γ/IL-5/IL-6/IL-17/IL-22 levels increased, while Treg cell proportions and IL-35 level dropped. With higher alopecia severity, the proportions of Th1, Th2 and Th17 cells increased, and Treg cell proportion decreased. AA patients with mild/moderate alopecia had significant differences in IL-17 level. Serum INF-γ, IL-5, IL-17 and IL-22 levels were elevated, and IL-35 level dropped in severe AA patients versus moderate AA patients.

CONCLUSION

Th1/Th2/Th17 cell proportions and serum INF-γ/IL-5/IL-6/IL-17/IL-22 levels in AA patients were up-regulated, while Treg cell proportion and IL-35 level were repressed. SALT scores were positively-correlated with serum IL-5/IL-17 levels. SALT scores were negatively-correlated with serum IL-35.

Epidemiology, Treatment Patterns, and Healthcare Resource Utilization Study of Patients With Alopecia Areata in Taiwan's National Health Insurance Research Database

OBJECTIVES

This study investigated the epidemiology, treatment patterns, and resource utilization in patients with alopecia areata (AA) in Taiwan using the National Health Insurance Research Database. AA severity was determined by treatment use and diagnostic codes in the year after enrollment (including corticosteroids, systemic immunosuppressants, topical immunotherapy, and phototherapy).

METHODS

The cross-sectional analysis was conducted to estimate the incidence and prevalence of AA from 2016 to 2020. For the longitudinal analysis, 2 cohorts were identified: mild/moderate and severe. The cohorts were matched based on age, gender, and comorbidities. Patients were enrolled upon their first claim with an AA diagnosis during the index period of 2017-2018.

RESULTS

The number of patients with AA increased from 3221 in 2016 to 3855 in 2020. The longitudinal analysis identified 1808 mild/moderate patients and 452 severe patients. Mild/moderate patients used higher levels of topical corticosteroids (82.41%) than severe patients (73.45%). Conversely, severe patients used more topical nonsteroids (41.81%) and systemic therapies (51.77%) than mild/moderate patients (0.44% and 16.15%, respectively). Oral glucocorticoids use was higher in severe patients (47.57%) relative to mild/moderate patients (14.88%), whereas the use of injectable forms was similar. The most used systemic immunosuppressants were methotrexate, cyclosporin, and azathioprine. Topical immunotherapy utilization decreased with subsequent treatment lines for severe patients. Treatment persistence at 6 months was low for all treatments. Severe patients had higher annual AA-related outpatient visits than the mild/moderate cohort.

CONCLUSIONS

These findings highlight the need for additional innovations and therapies to address the clinical and economic burden of AA.

IL-22 in Atopic Dermatitis

Atopic dermatitis (AD) is a prevalent and chronic inflammatory skin condition characterized by a multifaceted pathophysiology that gives rise to diverse clinical manifestations. The management of AD remains challenging due to the suboptimal efficacy of existing treatment options. Nonetheless, recent progress in elucidating the underlying mechanisms of the disease has facilitated the identification of new potential therapeutic targets and promising drug candidates. In this review, we summarize the newest data, considering multiple connections between IL-22 and AD. The presence of circulating IL-22 has been found to correlate with the severity of AD and is identified as a critical factor driving the inflammatory response associated with the condition. Elevated levels of IL-22 in patients with AD are correlated with increased proliferation of keratinocytes, alterations in the skin microbiota, and impaired epidermal barrier function. Collectively, these factors contribute to the manifestation of the characteristic symptoms observed in AD.

Global, regional and national epidemiology of alopecia areata: a systematic review and modelling study

BACKGROUND

Alopecia areata (AA) is a chronic autoimmune disease that leads to a high psychiatric, economic and systemic disease burden. A comprehensive understanding of AA epidemiology is essential for evaluating healthcare source utilization; however, a systematic approach to summarizing epidemiological data on AA is lacking.

OBJECTIVES

To investigate systematically the global, regional and national incidence and prevalence of AA.

METHODS

A structured search was conducted using the databases MEDLINE, Embase, Cochrane Library, Web of Science, SciELO and Korean Journal Database from their date of inception to 4 October 2023. Studies that reported the prevalence or incidence of AA were included. We used a Bayesian hierarchical linear mixed model to analyse prevalence estimates. The primary outcomes of our study were the global, regional and national prevalence of physician-diagnosed AA for the overall population, for adults and for children. The incidence data were summarized descriptively.

RESULTS

In total, 88 studies from 28 countries were included in the analysis. The reported incidence of AA tended to be higher in adults aged 19-50 years, and this trend was consistent with its estimated prevalence. The reported prevalence in overall populations tended to be higher in men vs. women. The estimated lifetime prevalence rate of AA was 0.10% [95% credible interval (CrI) 0.03-0.39] in the general population worldwide, 0.12% (95% CrI 0.02-0.52) in adults and 0.03% (95% CrI 0.01-0.12) in children. The estimated prevalence of AA was highest in the Asian region and lowest in the African region.

CONCLUSIONS

In this study, 48% of the Global Burden of Disease regions had insufficient data on the prevalence or incidence of AA. Further studies are needed to provide epidemiological information on middle- and low-income countries. Our study may serve as a crucial reference in terms of healthcare policy decisions.

Explore the genetic exposure to alopecia areata

BACKGROUND

Alopecia areata is an autoimmune hair loss disorder with an incompletely understood etiology. Although trace elements, serum metabolites, and inflammatory factors are implicated in the disease, the potential causal relationships between these factors and alopecia areata require further investigation.

METHODS

This study employed Mendelian randomization (MR), utilizing data from genome-wide association studies, to explore the causal relationships between 15 trace elements, 1400 serum metabolites, and 91 inflammatory factors and alopecia areata. The analysis was conducted using the inverse variance weighted (IVW) method complemented by various sensitivity analyses, including Cochran's Q test, MR-Egger regression intercept test, MR-PRESSO global test, and leave-one-out analysis, to assess the robustness of the results.

RESULTS

MR analysis indicated a negative correlation between copper levels and the risk of developing alopecia areata (odds ratio = 0.86, 95% confidence interval: 0.75-0.99, p = 0.041). Additionally, causal relationships were identified between 15 serum metabolites and 6 inflammatory factors and the risk of alopecia areata (IVW, all p values < 0.05).

CONCLUSION

This study provides genetic evidence of the relationships between trace elements, serum metabolites, and alopecia areata, underscoring the potential value of targeted therapeutic strategies and preventive measures. Future research should expand to diverse populations and further explore the specific roles of these biomarkers in the disease mechanism.

The Effect of an Oral Probiotic Mixture on Clinical Evolution and the Gut and Skin Microbiome in Patients with Alopecia Areata: A Randomized Clinical Trial

(1) Background: Given the autoimmune nature of Alopecia Areata (AA) and the immunomodulatory properties of probiotics, this trial was conducted to evaluate the efficacy of a probiotic mixture, consisting of Lactobacillus rhamnosus and Bifidobacterium longum strains, as an adjuvant treatment in a group of AA patients. (2) Method: This study was a 24-week, randomized, double-blind, placebo-controlled clinical trial. Twenty-six patients with AA were included in this study, and their clinical progression, along with changes in gut and skin microbiota, were analyzed. (3) Results: A higher proportion of AA patients treated with the probiotic formula showed improvement compared to the placebo group, based on both the reduction in the number of AA plaques (56% vs. 30%) and the affected scalp surface area (45% vs. 20%). For “activity”, “inactivity”, and “regrowth”, an improvement in 55%, 67%, and 55% of patients was, respectively, observed in the probiotic group, compared to 50%, 40%, and 30% in the placebo group. No changes were observed in the gut microbiota during the intervention period. Regarding skin microbiota, changes were detected in the probiotic group, with reductions in characteristic genera during the study. (4) Conclusions: To our knowledge, this is the first clinical trial assessing the efficacy of a probiotic product in patients with AA. This probiotic mixture in a routine clinical practice setting appears to improve the course of patients. In addition, the skin microbiota of scalp lesions was modified using the probiotic treatment.

The causal relationship between gut microbiota and alopecia areata: a Mendelian randomization analysis

Background

Increasing evidence suggests a robust correlation between the gut microbiome and alopecia areata. In light of the extensive diversity of gut microbiota, this study aims to utilize state-of-the-art and comprehensive data to explore the causative association between gut microbiota and alopecia areata.

Objective

We conducted a Mendelian randomization (MR)-based two-sample study to elucidate the causal relationship between gut microbiota and alopecia areata.

Method

Summary information on Ncase = 767 and Ncontrol = 394,105 cases of alopecia areata was obtained from the FinnGen study. A total of 473 gut microbial taxa were summarized from the genome-wide association study (GWAS) catalog. The study comprised a forward Mendelian randomization (MR) analysis with the gut microbiome as the exposure factor and alopecia areata as the outcome, as well as a reverse MR analysis with alopecia areata as the exposure factor and the gut microbiome as the outcome. Various analytical methods including inverse variance weighting (IVW), Weighted Median, MR-Egger, Weighted Mode, and Simple Mode were employed. Subsequently, sensitivity analysis was conducted to ensure the robustness of our research findings.

Result

This study has established a causal relationship between gut microbiota and alopecia areata. Forward causal analysis revealed causality relationships between 16 gut microbial taxa and alopecia areata, while reverse causal analysis found that there may be a causal relationship between alopecia areata and 16 gut microbial taxa (not statistically significant).

Conclusion

Our study findings suggest a causal relationship between gut microbiota and alopecia areata, providing potential guidance for future clinical trials.

Genetic association between asthma and alopecia areata: A two-sample Mendelian randomization study

BACKGROUND

Many patients with asthma experience alopecia areata (AA) in their lives. However, it is unclear whether asthma causes or results from AA. Our objective was to investigate the genetic causal relationship between asthma and AA.

METHODS

Two-sample Mendelian randomization (MR) was used to assess the causal relationship between asthma and AA based on the largest publicly available genome-wide association study summary statistics. Androgenetic alopecia (AGA) and cicatricial alopecia (CA) were chosen as the control groups for AA. The main estimates were obtained using inverse variance weighting meta-analysis (IVW), Mendelian randomization-Egger (MR-Egger), maximum likelihood estimation, and the weighted median. Sensitivity analyses were conducted using Cochran's Q test, MR-Egger, and leave-one-out methods. Lastly, we conducted a reverse MR analysis to evaluate the possibility of reverse causation.

RESULTS

Genetically, asthma is associated with an increased risk of AA, while the association between genetically predicted AGA or CA and asthma was negative. The risk of AA increased by 1.86 times in patients with asthma under the IVW method (OR = 1.86, 95% CI = 1.31-2.629, p < 0.001). The reverse MR analysis did not find evidence supporting reverse causality from three phenotypes of alopecia to asthma. Sensitivity analyses yielded consistent causal estimates.

CONCLUSION

This study suggests that asthma is causally associated with AA. The findings deepen our understanding of the role of asthma in the pathology of AA, which emphasizes the potential for opening a new vista for the prevention and diagnosis of AA.

Air pollution and skin diseases: A comprehensive evaluation of the associated mechanism

Air pollutants deteriorate the survival environment and endanger human health around the world. A large number of studies have confirmed that air pollution jeopardizes multiple organs, such as the cardiovascular, respiratory, and central nervous systems. Skin is the largest organ and the first barrier that protects us from the outside world. Air pollutants such as particulate matter (PM), polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs) will affect the structure and function of the skin and bring about the development of inflammatory skin diseases (atopic dermatitis (AD), psoriasis), skin accessory diseases (acne, alopecia), auto-immune skin diseases (cutaneous lupus erythematosus(CLE) scleroderma), and even skin tumors (melanoma, basal cell carcinoma (BCC), squamous-cell carcinoma (SCC)). Oxidative stress, skin barrier damage, microbiome dysbiosis, and skin inflammation are the pathogenesis of air pollution stimulation. In this review, we summarize the current evidence on the effects of air pollution on skin diseases and possible mechanisms to provide strategies for future research.

Deciphering the Complex Immunopathogenesis of Alopecia Areata

Alopecia areata (AA) is an autoimmune-mediated disorder in which the proximal hair follicle (HF) attack results in non-scarring partial to total scalp or body hair loss. Despite the growing knowledge about AA, its exact cause still needs to be understood. However, immunity and genetic factors are affirmed to be critical in AA development. While the genome-wide association studies proved the innate and acquired immunity involvement, AA mouse models implicated the IFN-γ- and cytotoxic CD8+ T-cell-mediated immune response as the main drivers of disease pathogenesis. The AA hair loss is caused by T-cell-mediated inflammation in the HF area, disturbing its function and disrupting the hair growth cycle without destroying the follicle. Thus, the loss of HF immune privilege, autoimmune HF destruction mediated by cytotoxic mechanisms, and the upregulation of inflammatory pathways play a crucial role. AA is associated with concurrent systemic and autoimmune disorders such as atopic dermatitis, vitiligo, psoriasis, and thyroiditis. Likewise, the patient's quality of life (QoL) is significantly impaired by morphologic disfigurement caused by the illness. The patients experience a negative impact on psychological well-being and self-esteem and may be more likely to suffer from psychiatric comorbidities. This manuscript aims to present the latest knowledge on the pathogenesis of AA, which involves genetic, epigenetic, immunological, and environmental factors, with a particular emphasis on immunopathogenesis.

Non-Cicatricial Alopecia and Its Association with Anthropometric Measurements and Nutritional Laboratory Markers

Alopecia constitutes one of the most common dermatological disorders, and its steadily increasing prevalence is a cause for concern. Alopecia can be divided into two main categories, cicatricial/scarring and non-cicatricial/non-scarring, depending on the causes of hair loss and its patterns. The aim of this study was to investigate the relationship between anthropometric and nutritional laboratory parameters in Caucasian adult women and men with non-cicatricial alopecia. A total of 50 patients (37 with non-cicatricial alopecia and 13 healthy controls) were included in the study. Clinical examination and scalp trichoscopy were performed. The anthropometric and nutritional laboratory parameters were collected and analyzed. No statistically significant differences in the laboratory findings were found. The patients with non-cicatricial alopecia were statistically significantly younger as compared to the controls. An elevated risk of hair loss, which was detected among the younger participants, might be associated with a modern lifestyle and the so-called 'Western diet'. It seems safe to assume that suboptimal nutrition and poor eating habits during childhood might constitute risk factors for early hair loss.

Bilateral Association Between Atopic Dermatitis® and Alopecia Areata: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis aimed to explore the association between atopic Dermatitis® (AD) and alopecia areata (AA). A comprehensive search was conducted in PubMed, Embase, Cochrane, and Web of Science from the inception of each database to November 10, 2022 for relevant studies. As there is a potential bilateral association between the 2 diseases, we assessed the prevalence/incidence of AA in patients with AD and the prevalence/incidence of AD in patients with AA. A total of 29 studies involving 11,233,448 participants were included in this analysis. AA was the exposure factor in 23 studies, AD in 7 studies, and both in 1 study. The meta-analysis revealed that the prevalence of AD was 11.2% (7.7%-15.1%) in patients with AA, and the prevalence of AA was 3.2% (95% confidence interval [CI]: 0.0%-11.5%) in patients with AD. The incidence of AD in AA patients was found to vary with age (P = 0.07). Based on 7 studies, there was a significant association between AD and AA when AA was the exposure factor [odds ratio, OR, = 4.537 (95% CI: 2.409-8.544)]; based on 10 studies, there was also a significant association between AD and AA when AD was the exposure factor [OR = 2.643 (95% CI: 1.737-3.995)]. In conclusion, this meta-analysis demonstrated the 2-way association between AD and AA, providing a clinical reference for disease prevention and control.

Classification of psychodermatological disorders: Proposal of a new international classification

INTRODUCTION

Several classifications of psychodermatology disorders have been proposed, with most of them based on two to four main disorder category groups. However, there is, to date, no classification that has resulted from a consensus established by psychodermatology experts. The DSM-5-TR (Diagnostic and statistical manual of mental disorders (5th ed.), Text Revision) and the ICD-11 (International classification of diseases (11th revision)) also do not provide a systematized approach of psychodermatology disorders. Taking into consideration that classifications are a key pillar for a comprehensive approach to the pathologies of each branch of medicine, the proposal of a classification in psychodermatology appeared as a central need for the recognition of psychodermatological disorders, in an attempt to improve their recognition and, in that sense, to find a common language for the development of this subspecialty that crosses dermatology and psychiatry.

METHODS

Previously published classifications in psychodermatology were critically reviewed and discussed by expert opinion from an international multidisciplinary panel of 16 experts in psychodermatology and a new classification system is proposed, considering classical concepts in general dermatology and psychopathology.

RESULTS

Two main categories of disorders are presented (a main group related to primary mental health disorders and another main group related to primary skin disorders), which are subsequently subdivided into subgroups considering pathophysiological and phenomenological similarities, including key aspects of dermatological examination, namely the presence of visible skin lesions (primary and secondary skin lesions) and psychopathological correlates.

CONCLUSION

This new classification aims to unify previous classifications, systematize the disorders that belong to psychodermatology and highlight their tenuous boundaries, to improve their management. It has been built and approved by the Psychodermatology Task Force of the European Academy of Dermatology and Venereology (EADV), the European Society for Dermatology and Psychiatry (ESDaP) and the Association for Psychoneurocutaneous Medicine of North America (APMNA).

Comparison of Efficacy of Topical Betamethasone Dipropionate and Topical Minoxidil in Patients With Alopecia Areata

Background and objective Alopecia areata (AA) is a reiterative and nonscarring type of hair loss that can affect any hairy area of the body, particularly the scalp. It manifests as patchy or confluent hair loss with variations in demographics and ethnicity. There are numerous treatment options available, including topical and systemic steroids, topical minoxidil, dithranol, tacrolimus, psoralen and ultraviolet therapy (PUVA), contact immunotherapy, and oral immunosuppressive drugs. However, no previous contrast for efficacy is present between the topical betamethasone versus topical minoxidil alone in our population. This study aims to compare the efficacy of topical betamethasone dipropionate versus topical minoxidil in patients with AA. Methodology A nonrandomized controlled study was conducted at the Department of Dermatology, Jinnah Hospital Lahore, incorporating the data of patients between July 26, 2016, and January 26, 2017, after obtaining institutional ethical approval. One hundred patients with alopecia, either on the scalp or any other hairy part, from both genders, aged between 18 and 50 years, were included in the study. Two groups were created, and patients were assigned to these groups based on the clinician's choice. Group A patients were administered betamethasone dipropionate (0.05%) lotion twice daily on affected areas for 12 weeks. Group B patients were administered minoxidil (5%) solution twice daily on affected areas for 12 weeks. A four-week follow-up plan was followed. A five-point scale score system was used for alopecia grading. After 12 weeks, the hair regrowth score (RGS) was used to compare the efficacy of treatment between the two groups. Results A total of 100 patients with grades S1 to S3 AA of less than three months duration were enrolled. Two groups were created, with 50 patients in each group. The mean age in Group A was 29.08 ± 6.51 years, while in Group B, it was 29.38 ± 6.62 years. In Group A, there were 76% males and 24% females, while in Group B, there were 74% males and 26% females. Comparison of efficacy of topical betamethasone dipropionate versus topical minoxidil in patients with AA demonstrated a greater efficacy of 74% (Grade 3 and Grade 4 responses) in Group A, while in Group B, only 42% of patients showed efficacy. A statistically significant difference was found, with a P-value of 0.001. No serious side effects were noted. Conclusions Our study concluded that topical betamethasone dipropionate (0.05%) lotion has statistically significantly higher efficacy compared to topical minoxidil (5%) solution in patients with AA.

Association of Obesity and Bariatric Surgery on Hair Health

Obesity and obesity-related conditions today constitute a public health problem worldwide. Obesity is an "epidemic" chronic disorder, which is defined by the WHO as normal or excessive fat accumulation that may impair health. It is also defined for adults as a BMI that is greater than or equal to 30. The most common obesity-related diseases are type 2 diabetes mellitus, cardiovascular diseases, metabolic syndrome, chronic kidney disease, hyperlipidemia, hypertension, nonalcoholic fatty liver disease, and certain types of cancer. It has been also proven that obesity can have a negative effect on hair. It can lead to hair thinning. Patients with obesity can undergo bariatric surgery if they meet the inclusion criteria. The four common types of weight loss surgery include a duodenal switch with biliopancreatic diversion, laparoscopic adjustable gastric banding, Roux-en-Y gastric bypass, and sleeve gastrectomy. Bariatric surgery can affect skin and hair and is associated with telogen effluvium due to weight loss, microelement deficiency, anesthesia, low calorie intake, and low protein intake. Patients who undergo bariatric surgery can experience post-bariatric surgery depression. Hair loss can have a major impact on self-esteem, negatively affecting one's self-image. The purpose of this narrative review is to critically review how obesity, obesity-related diseases, and bariatric surgery affect hair health in general and the hair development cycle, and how they influence hair loss.

Mendelian randomization study highlights hypothyroidism as a causal determinant of alopecia areata

Background

Although observational studies have found an association between hypothyroidism and alopecia areata, the causality of this relationship remains unclear.

Objectives

This study aimed to investigate the genetic variants associated with hypothyroidism and their potential impact on the risk of developing alopecia areata.

Methods

genome-wide association study summary statistics for hypothyroidism (30,155 cases and 379,986 controls) and alopecia areata (289 cases and 211,139 controls) were obtained from the IEU OpenGwas project. The inverse variance-weighted method was used as the primary analysis method to evaluate the causality between hypothyroidism and alopecia areata, supplemented by the weighted median, MR-Egger, simple mode and weighted mode. Furthermore, the function of causal SNPs was evaluated by gene ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, and protein-protein interaction networks.

Result

Utilizing two-sample Mendelian randomization analysis, we found that the single-nucleotide polymorphisms (SNPs) of hypothyroidism (OR = 1.40, 95% CI: 1.12-1.75, p = 3.03×10-3) significantly increased the risk of alopecia areata ( 289 cases and 211,139 controls ). KEGG pathway analysis showed that the candidate genes were mainly enriched in virion-herpesvirus, Th1 and Th2 cell differentiation, Th17 cell differentiation, T-cell receptor signaling pathway, PD-L1/PD-1 checkpoint pathway in cancer and Toll-like receptor signaling pathway. Protein-protein interaction networks results showed that CTLA4, STAT4, IL2RA, TYK2, IRF7, SH2B3, BACH2, TLR3, NOD2, and FLT3.

Conclusion

This study provided compelling genetic evidence supporting a causative association between hypothyroidism and alopecia areata, which could potentially inform the development of more efficacious treatment strategies for patients afflicted by alopecia areata.

A comparative study of fractional CO2 laser with topical triamcinolone acetonide versus intralesional triamcinolone acetonide in the treatment of alopecia areata

Introduction

Alopecia areata (AA) is a non-scarring alopecia of chronic autoimmune etiology with heterogenous severity against the anagen hair follicle over the scalp, beard, or any part of the body and is associated with a significant psychological morbidity in the mental status of the patients leading the patients to seek treatment for cosmetic reasons. The management of AA is very unpredictable and is associated with various cosmetic adverse effects. This study aimed at comparing the efficacy and safety of a novel procedure of laser-assisted drug delivery system of steroids with the first-line procedure of intralesional steroids (ILS) for the treatment of patchy AA.

Aims and Objectives

To assess and compare the efficacy and safety of fractional CO2 laser in combination with topical triamcinolone acetonide aqueous solution and intralesional triamcinolone acetonide as a monotherapy and in the treatment of AA.

Materials and Methods

A total of 60 patchy AA patients were included in this study. Patients were randomized into two equal groups: Group A and Group B with 30 patients in each group using a computer-generated block randomization. Patients in Group A received fractional CO2 laser with topical triamcinolone acetonide aqueous solution and Group B received ILS. Both groups received treatment for five settings with each setting a gap of 3 weeks. The efficacy and safety of treatment modalities in both groups were assessed using global photograph assessment (GPA)-scale, lesional area density score percentage of improvement (LAD score improvement %), visual discomfort scale (VDS), visual analogue scale, and documentation of adverse effects in each setting.

Results

Efficacy of treatment modality-assessed using means score of GPA-scale and LAD score improvement % suggests quicker results to patients in Group B in initial settings but drastic improvement happens to patients in Group A in subsequent settings. At the end of 5th setting, GPA-scale and LAD score improvement % suggest maximum efficacy in patients in Group A and they are statistically significant (P-value < 0.001). The mean VDS in both groups suggests maximum discomfort in Group A, yet the patient satisfaction at the end of 5th setting was maximum with patients in Group A and they are statistically significant (P-value < 0.001). Cosmetic notable adverse effect of atrophy of skin was documented in 30% of patients in Group B.

Conclusion

This study showed that fractional CO2 laser with topical triamcinolone acetonide is a better treatment modality than the intralesional triamcinolone acetonide for the treatment of AA with respect to efficacy, safety, and adverse events.

Efficacy, safety, and Pharmacoeconomics of Three Common Strategies for Pediatric Alopecia Areata Patients: A Retrospective Cohort Study

Objective

To evaluate and explore the efficacy, safety, and pharmacoeconomics of three common strategies for pediatric alopecia areata.

Methods

Chinese pediatric alopecia areata patients meeting the criteria were included and divided into three groups based on the received treatments. The efficacy, adverse events and pharmacoeconomics of these treatments were retrospectively analyzed.

Results

Twenty-four pediatric AA patients were recruited in this study. 100% (12/12) of patients from the traditional group achieved SALT100. In the tofacitinib group, 40.0% (2/5) of patients achieved SALT50. 20.0% (1/5) of patients achieved SALT75 and 40.0% (2/5) of patients achieved SALT100. In the MN group, 42.86% (3/7) of patients were non-responders. 14.28 (1/7) of patients achieved SALT75 and 42.86% (3/7) of patients achieved SALT100. The adverse effects (AEs) were mild in all three groups, and none of the patients discontinued the treatments due to the AEs. Comparing the other two groups, the MN treatment would be more time-intensive and more expensive.

Conclusion

For newly diagnosed or naive pediatric patients, the traditional treatment was the first-line approach. For long-duration, severe and refractory patients, tofacitinib and microneedling can be alternative options.

Alopecia Areata in Latin America: Where are We and Where are We Going?

Alopecia areata (AA) represents an underrecognized burden in Latin America (LA), severely impacting quality of life (QoL). This impact is exacerbated by limited access to specialized dermatologic care and therapies for AA within and among nations. Many of the unmet needs for AA globally also exist in LA. The region has geographic, ethnic, cultural, and economic conditions. With new AA medicines targeting immunologic pathways on the horizon, LA must prepare regarding regulatory issues, reimbursement, awareness, and education to give adequate and timely treatment for patients with AA. To address these issues, the Americas Health Foundation convened a panel of six dermatologists from Argentina, Brazil, Colombia, and Mexico who are experts in AA and its comorbidities for a 3-day virtual meeting to discuss AA diagnosis and treatment in LA and create a manuscript offering recommendations to address discussed barriers. This publication examines unmet AA needs in LA, treatment, and innovative therapies and recommends improving AA care. Access constraints to conventional and novel medicines hinder appropriate treatments for patients. Therapy initiation delays can affect QoL, mental health, and disease progression. People with AA face stigmas, discrimination, and misconceptions owing to a lack of disease awareness. With promising new treatments for AA on the horizon, all stakeholders must coordinate efforts to enhance LA's AA management landscape and improve patient outcomes.

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.