Role of cytomegalovirus replication in alopecia areata pathogenesis

Ophiasis Pattern Alopecia Areata in an Infant

Alopecia areata (AA), an autoimmune inflammatory disorder causing non-scarring hair loss, predominantly affects the adult population and is rarely encountered in young infants and neonates. The etiology of this condition remains multifactorial, involving complex interactions between genetic, autoimmune, and environmental factors. In this report, we present a notable case of a four-month-old infant who presented with distinct band-like hair loss on the right inferior lateral forehead, left inferior lateral forehead, and superior middle forehead following a culturally significant head-shaving ritual known as Chudakarana. This unique presentation of ophiasis AA in an infant is an unusual occurrence and has been associated with a poor prognosis. The patient received topical treatment with triamcinolone 0.1% lotion, resulting in improvement of alopecia at the six-week follow-up, although complete resolution of symptoms was not achieved. This case highlights the significance of recognizing atypical presentations of AA in the pediatric population and underscores the complexities in associated cultural factors.

Alopecia Areata: Burden of Disease, Approach to Treatment, and Current Unmet Needs

Alopecia areata is an autoimmune hair loss disorder with variations in distribution, duration, and severity. The disease is chronic and often follows an unpredictable course, frequently leading to stress and anxiety for those who suffer from it. Throughout the years more knowledge has been gained regarding pathogenesis, diagnostic tools, impact on quality of life, as well as treatment strategies for alopecia areata. However, challenges in treating and alleviating the burden of disease remain. In this article, we discuss updates regarding the pathogenesis and treatment of alopecia areata and highlight unmet needs of the condition, including a review of limitations of current treatments, accessibility to management strategies, and the need for disease awareness and advocacy.

The Human Skin Microbiome in Selected Cutaneous Diseases

The human skin harbors a wide variety of microbes that, together with their genetic information and host interactions, form the human skin microbiome. The role of the human microbiome in the development of various diseases has lately gained interest. According to several studies, changes in the cutaneous microbiota are involved in the pathophysiology of several dermatoses. A better delineation of the human microbiome and its interactions with the innate and adaptive immune systems could lead to a better understanding of these diseases, as well as the opportunity to achieve new therapeutic modalities. The present review centers on the most recent knowledge on skin microbiome and its participation in the pathogenesis of several skin disorders: atopic and seborrheic dermatitis, alopecia areata, psoriasis and acne.

Epidemiology, management and the associated burden of mental health illness, atopic and autoimmune conditions, and common infections in alopecia areata: protocol for an observational study series

INTRODUCTION

Alopecia areata (AA) is a common cause of immune-mediated non-scarring hair loss. Links between AA and common mental health, autoimmune and atopic conditions, and common infections have previously been described but remain incompletely elucidated and contemporary descriptions of the epidemiology of AA in the UK are lacking.

METHODS AND ANALYSIS

Retrospective study series using a large population-based cohort (5.2 million) from the Oxford Royal College of General Practitioners (RCGP) Research and Surveillance Centre (RSC) database, exploring four themes: AA epidemiology, mental health comorbidities, autoimmune/atopic associations and common infections.In the epidemiology theme, we will describe the incidence and point prevalence of AA overall and by age, sex and sociodemographic factors. Healthcare utilisation (primary care visits and secondary care referrals) and treatments for AA will also be assessed. In the mental health theme, we will explore the prevalence and incidence of mental health conditions (anxiety, depressive episodes, recurrent depressive disorder, adjustment disorder, agoraphobia, self-harm and parasuicide) in people with AA compared with matched controls. We will also explore the mental health treatment patterns (medication and psychological interventions), time off work and unemployment rates. Within the autoimmune/atopic associations theme, we will examine the prevalence of atopic (atopic dermatitis, allergic rhinitis, asthma) and autoimmune conditions (Crohn's disease, ulcerative colitis, coeliac disease, type 1 diabetes, Hashimoto's thyroiditis, Graves' disease, rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, systemic lupus erythematosus (SLE), polymyalgia rheumatica, Sjögren's syndrome, psoriasis, vitiligo, multiple sclerosis, pernicious anaemia) in people with AA compared with matched controls. We will also estimate the incidence of new-onset atopic and autoimmune conditions after AA diagnosis. Within the common infections theme, we will examine the incidence of common infections (respiratory tract infection, pneumonia, acute bronchitis, influenza, skin infection, urinary tract infection, genital infections, gastrointestinal infection, herpes simplex, herpes zoster, meningitis, COVID-19) in people with AA compared with matched controls.

ETHICS AND DISSEMINATION

The Health Research Authority decision tool classed this a study of usual practice, ethics approval was not required. Study approval was granted by the RCGP RSC Study Approval Committee. Results will be disseminated through peer-reviewed publications.

OBSERVATIONAL STUDY REGISTRATION NUMBER

NCT04239521.

The role of the microbiome in scalp hair follicle biology and disease

The skin surface microbiome and its role in skin diseases have received increasing attention over the past years. Beyond, there is evidence for a continuous exchange with the cutaneous immune system in healthy skin, where hair follicles (HFs) provide unique anatomical niches. Especially, scalp HFs form large tubular invaginations, which extend deeply into the skin and harbour a variety of microorganisms. The distinct immunology of HFs with enhanced immune cell trafficking in superficial compartments in juxtaposition to immune-privileged sites crucial for hair follicle cycling and regeneration makes this organ a highly susceptible structure. Depending on composition and penetration depth, microbiota may cause typical infections, but may also contribute to pro-inflammatory environment in chronic inflammatory scalp diseases. Involvement in hair cycle regulation and immune cell maturation has been postulated. Herein, we review recent insights in hair follicle microbiome, immunology and penetration research and discuss clinical implications for scalp health and disease.

Alopecia areata: A multifactorial autoimmune condition

Alopecia areata is an autoimmune disease that results in non-scarring hair loss, and it is clinically characterised by small patches of baldness on the scalp and/or around the body. It can later progress to total loss of scalp hair (Alopecia totalis) and/or total loss of all body hair (Alopecia universalis). The rapid rate of hair loss and disfiguration caused by the condition causes anxiety on patients and increases the risks of developing psychological and psychiatric complications. Hair loss in alopecia areata is caused by lymphocytic infiltrations around the hair follicles and IFN-γ. IgG antibodies against the hair follicle cells are also found in alopecia areata sufferers. In addition, the disease coexists with other autoimmune disorders and can come secondary to infections or inflammation. However, despite the growing knowledge about alopecia areata, the aetiology and pathophysiology of disease are not well defined. In this review we discuss various genetic and environmental factors that cause autoimmunity and describe the immune mechanisms that lead to hair loss in alopecia areata patients.

Alopecia Areata: a Comprehensive Review of Pathogenesis and Management

Alopecia areata is a common hair loss condition that is characterized by acute onset of non-scarring hair loss in usually sharply defined areas ranging from small patches to extensive or less frequently diffuse involvement. Depending on its acuity and extent, hair loss is an important cause of anxiety and disability. The current understanding is that the condition represents an organ-specific autoimmune disease of the hair follicle with a genetic background. Genome-wide association studies provide evidence for the involvement of both innate and acquired immunity in the pathogenesis, and mechanistic studies in mouse models of alopecia areata have specifically implicated an IFN-γ-driven immune response, including IFNγ, IFNγ-induced chemokines and cytotoxic CD8 T cells as the main drivers of disease pathogenesis. A meta-analysis of published trials on treatment of alopecia areata states that only few treatments have been well evaluated in randomized trials. Nevertheless, depending on patient age, affected surface area and disease duration, an empiric treatment algorithm can be designed with corticosteroids and topical immunotherapy remaining the mainstay of therapy. The obviously limited success of evidence-based therapies points to a more important complexity of hair loss. At the same time, the complexity of pathogenesis offers opportunities for the development of novel targeted therapies. New treatment opportunities based on the results of genome-wide association studies that implicate T cell and natural killer cell activation pathways are paving the way to new approaches in future clinical trials. Currently, there are ongoing studies with the CTLA4-Ig fusion protein abatacept, anti-IL15Rβ monoclonal antibodies and the Janus kinase inhibitors tofacitinib, ruxolitinib and baricitinib. Ultimately, the options available for adapting to the disease rather than treating it in an effort to cure may also be taken into consideration in selected cases of long-standing or recurrent small spot disease.

Evaluation of the Relationship between Alopecia Areata and Viral Antigen Exposure

BACKGROUND

Alopecia areata (AA) is an autoimmune disease characterized by non-scarring alopecia with T-cell infiltration at the affected hair follicle.

OBJECTIVE

Our aim was to study the potential link between hepatitis B virus (HBV) antigen exposure and AA.

METHODS

Two pediatric patients with AA following hepatitis B vaccination were identified in a general dermatology clinic. A bioinformatics analysis and an electronic medical record (EMR) database query were performed at the University of Rochester Medical Center to identify patients with AA, coexisting viral infections, vaccinations, or interferon (IFN) therapy in order to determine if the presence of AA and these conditions was higher than in AA patients without these associated conditions or therapy.

RESULTS

An increased frequency of AA among those who received the HBV surface protein antigen [odds ratio (OR) 2.7, p < 0.0001] was identified, and an independent analysis revealed an increased frequency of AA in those receiving IFN-β treatment (OR 8.1, p < 0.05). One potential antigenic target identified was SLC45A2, a melanosomal transport protein important in skin and hair pigmentation. The longest potential vaccine peptide fragment match (8-mer) was to a segment of natural killer (NK) cell inhibitory receptors, KIR3DL2 and KIR3DL1. Predictive modeling of major histocompatibility complex (MHC)-peptide binding demonstrated potential binding of this peptide to MHC relevant to AA.

LIMITATIONS

The results will need to be verified in additional patient databases allowing analysis of temporal relationships, and with molecular experiments of the identified antigens.

CONCLUSIONS

Our data confirm associations between viral infection and IFN treatment with AA. It establishes that the hepatitis B surface protein antigen has shared epitopes with human killer immunoglobulin-like receptors.

Systemic causes of hair loss

Hair loss is both a common chief complaint by patients and a clinical challenge for physicians, especially general practitioners, yet few dermatological problems yield as much patient satisfaction when resolved as hair loss. The diagnosis is often attributed to androgen-related hair loss, while other causes, some of which are life-threatening but treatable, are overlooked. We searched for relevant literature on hair loss and supported these findings with our clinical experience to identify seven major systemic etiologies of hair loss, ranging from infectious agents to consumption of unsafe supplements. Many causes are only described in the literature through case studies, though some original articles and meta-analyses are available. Careful history taking, proper examination techniques, and judicious use of laboratory tests are essential to reach at the correct diagnosis in a cost-effective manner when performing patient work-up. Such methodical evaluation of hair loss can result in the appropriate treatment plan and provide significant patient satisfaction. Key messages Hair loss is a common chief complaint and a difficult challenge for both general practitioners and dermatology consultants. We identified seven major categories of systemic hair loss etiology and present a framework for their clinical evaluation. A methodical approach to hair loss can result in the appropriate treatment plan and provide significant patient satisfaction.

What causes alopecia areata?

The pathobiology of alopecia areata (AA), one of the most frequent autoimmune diseases and a major unsolved clinical problem, has intrigued dermatologists, hair biologists and immunologists for decades. Simultaneously, both affected patients and the physicians who take care of them are increasingly frustrated that there is still no fully satisfactory treatment. Much of this frustration results from the fact that the pathobiology of AA remains unclear, and no single AA pathogenesis concept can claim to be universally accepted. In fact, some investigators still harbour doubts whether this even is an autoimmune disease, and the relative importance of CD8(+) T cells, CD4(+) T cells and NKGD2(+) NK or NKT cells and the exact role of genetic factors in AA pathogenesis remain bones of contention. Also, is AA one disease, a spectrum of distinct disease entities or only a response pattern of normal hair follicles to immunologically mediated damage? During the past decade, substantial progress has been made in basic AA-related research, in the development of new models for translationally relevant AA research and in the identification of new therapeutic agents and targets for future AA management. This calls for a re-evaluation and public debate of currently prevalent AA pathobiology concepts. The present Controversies feature takes on this challenge, hoping to attract more skin biologists, immunologists and professional autoimmunity experts to this biologically fascinating and clinically important model disease.

Etiopathogenesis of alopecia areata: Why do our patients get it?

Alopecia areata (AA) is a nonscarring, inflammatory skin disease that results in patchy hair loss. AA is unpredictable in its onset, severity, and duration making it potentially very stressful for affected individuals. Currently, the treatment options for AA are limited and the efficacy of these treatments varies from patient to patient. The exact etiology of AA is unknown. This article provides some insights into the etiopathogenesis of AA and why some people develop it. The current knowledge on the pathogenesis of AA is summarized and some of the recent hypotheses and studies on AA are presented to allow for a fuller understanding of the possible biological mechanisms of AA.

Recombinant human hepatitis B vaccine initiating alopecia areata: testing the hypothesis using the C3H/HeJ mouse model

Untoward effects of human vaccines suggest that recombinant hepatitis B vaccine may induce alopecia areata (AA) in some patients. Similar untoward immunological effects may also account for AA-like diseases in domestic species. In this study, the C3H/HeJ spontaneous adult onset AA mouse model was used to test the role, if any, of recombinant hepatitis B vaccine on the initiation or activation of AA. Initial experiments demonstrated no effect on induction of AA in young adult female C3H/HeJ mice (P = 0.5689). By contrast, older females, those at the age when AA first begins to appear in this strain, had a significant increase (P = 0.0264) in the time of onset of AA, suggesting that the vaccine may initiate disease in mice predisposed to AA. However, larger vaccine trials, which included diphtheria and tetanus toxoids as additional controls, did not support these initial result findings and suggest that AA associated with vaccination may be within the normal background levels of the given population.