Frontal fibrosing alopecia: reflections and hypotheses on aetiology and pathogenesis

Enhanced Insights into Frontal Fibrosing Alopecia: Advancements in Pathogenesis Understanding and Management Strategies

Frontal fibrosing alopecia (FFA) represents a distinctive form of primary lymphocytic scarring alopecia characterized by fronto-temporal hair recession and eyebrow hair loss. While predominantly affecting postmenopausal women, FFA also occurs in women of reproductive age and men, with variations observed across different ethnic groups. Genetic predisposition, environmental factors and inflammatory pathways contribute to its pathogenesis, with evolving diagnostic criteria enhancing accuracy. FFA treatment lacks standardization, encompassing topical, systemic and physical therapies, while hair transplantation remains a temporary solution. This article reviews the current understanding of FFA, aiming to provide clinicians with updated insights for its management.

A review of isotretinoin in the treatment of frontal fibrosing alopecia

INTRODUCTION

Frontal fibrosing alopecia (FFA) is characterized by scarring alopecia of the frontotemporal scalp and facial papules. Isotretinoin is a vitamin A-derived retinoid discovered in 1955 and approved for treating nodulocystic acne. This drug can also affect facial papules and frontotemporal hair loss in patients with FFA. In this article, we conducted a review of the available studies investigating the use of oral isotretinoin for FFA treatment. Our study provides insights into the efficacy and safety of isotretinoin as a potential treatment option for FFA and highlights areas for future research.

METHOD

In this study, we aimed to investigate the potential advantages and disadvantages of isotretinoin as a treatment for FFA. To identify all relevant articles, we developed a comprehensive search strategy and conducted a thorough search of three major databases: PubMed, Embase, and Science Direct. We retrieved a total of 82 articles from the search results. Two independent reviewers then screened each of the 82 articles based on our inclusion and exclusion criteria, resulting in the identification of 15 articles that were deemed relevant to our study.

RESULTS

Across the 15 articles, 232 patients who suffered from FFA were involved. Nearly 90% of patients experienced a significant reduction of symptoms after receiving oral isotretinoin at 10-40 mg daily. We conclude that isotretinoin can positively affect facial papules and help suppress hair loss.

Clinical effectiveness of finasteride versus hydroxychloroquine in the treatment of frontal fibrosing alopecia: A randomized controlled trial

BACKGROUND

Frontal fibrosing alopecia (FFA) is a cicatricial alopecia with rapid epidemic growth. However, there is no agreement on the best therapeutic approach.

AIMS

To compare the therapeutic effects of finasteride as a first-line systemic treatment of FFA versus hydroxychloroquine as a relatively safe and effective immunosuppressive drug.

METHODS

Thirty-four female FFA patients were randomly assigned to receive either 400 mg/day of hydroxychloroquine or 2.5 mg/day of finasteride for 6 months. Topical treatments in both groups include pimecrolimus, mometasone, and minoxidil. Treatment efficacy was evaluated using the Frontal Fibrosing Alopecia Severity Score (FFASS), photography, and trichoscopy after 3 and 6 months.

RESULTS

Both the finasteride and hydroxychloroquine groups showed significant improvements in FFASS and trichoscopic scores (p < 0.01). However, there was no significant difference between the two groups during the study. Photographic assessment showed that more than 60% of patients in both groups had improved without statistically significant differences between the two groups.

CONCLUSIONS

Both finasteride and hydroxychloroquine are equally effective, safe, and well-tolerable for treating FFA patients.

Genotyping of the rs1800440 Polymorphism in CYP1B1 Gene and the rs9258883 Polymorphism in HLA-B Gene in a Spanish Cohort of 223 Patients with Frontal Fibrosing Alopecia

The pathogenesis of frontal fibrosing alopecia has been linked to specific genetic variants. CYP1B1 codes for a component of the cytochrome p450 machinery that is involved in the metabolism of xenobiotic oestrogens. The study of the prevalence of polymorphisms in this gene may help to understand their role in the development of frontal fibrosing alopecia. The aim of this study is to describe the frequency of genetic variations in the alleles HLA-B*07:02 and CYP1B1 in patients with frontal fibrosing alopecia. A cross-sectional study was designed to evaluate blood samples from patients with frontal fibrosing alopecia who attended the Dermatology Department at University Hospital Ramón y Cajal (Madrid, Spain), in search of the polymorphisms rs9258883 and rs1800440 in the alleles HLA-B*07:02 and CYP1B1, respectively. A total of 223 patients were included in the study. Among the 83.8% of patients who carried the rs9258883 polymorphism in HLA-B*07:02, 58.7% were heterozygous for this variant and it was not present in 14.8% of the cases. The majority of patients with frontal fibrosing alopecia lacked the protective rs1800440 polymorphism in CYP1B1 (75.2%). This suggests a relevant role of this variant in development of frontal fibrosing alopecia. The genetic approach to this condition might influence patient prognosis and therapy options.

Frontiers in Lichen Planopilaris and Frontal Fibrosing Alopecia Research: Pathobiology Progress and Translational Horizons

Lichen planopilaris (LPP) and frontal fibrosing alopecia (FFA) are primary, lymphocytic cicatricial hair loss disorders. These model epithelial stem cell (SC) diseases are thought to result from a CD8⁺ T-cell‒dominated immune attack on the hair follicle (HF) SC niche (bulge) after the latter has lost its immune privilege (IP) for as yet unknown reasons. This induces both apoptosis and pathological epithelial‒mesenchymal transition in epithelial SCs, thus depletes the bulge, causes fibrosis, and ultimately abrogates the HFs' capacity to regenerate. In this paper, we synthesize recent progress in LPP and FFA pathobiology research, integrate our limited current understanding of the roles that genetic, hormonal, environmental, and other factors may play, and define major open questions. We propose that LPP and FFA share a common initial pathobiology, which then bifurcates into two distinct clinical phenotypes, with macrophages possibly playing a key role in phenotype determination. As particularly promising translational research avenues toward direly needed progress in the management of these disfiguring, deeply distressful cicatricial alopecia variants, we advocate to focus on the development of bulge IP and epithelial SC protectants such as, for example, topically effective, HF‒penetrating and immunoinhibitory preparations that contain tacrolimus, peroxisome proliferator-activated receptor-γ, and/or CB1 agonists.

Diagnostic implications of MicroRNAs; 155, 146 a, and 203 lesional expression in alopecia areata: A preliminary case-controlled study

BACKGROUND

Alopecia areata (AA) is an immune mediated disorder that attacks hair follicles with unknown pathophysiology. MicroRNAs (miRNAs) are small noncoding RNA molecules, and their aberrant expression or function has been involved in different autoimmune conditions.

OBJECTIVES

We aimed at exploring the association between some miRNAs lesional expression and AA pathogenesis by measurement of miRNAs-155, 146a, and 203 expression levels in the lesional skin from patchy AA patients and to evaluate their relation with the studied parameters.

SUBJECTS AND METHODS

Skin expression levels of miRNAs-155, 146a, and 203 were evaluated in 50 patients with patchy AA and 25 healthy controls using reverse transcriptase-quantitative PCR (RT-qPCR). The activity and severity of alopecia were assessed according to AA Investigational Assessment Guidelines criteria.

RESULTS

Studied patients showed significant up-regulation of miRNAs-203, 146a, and 155 lesional tissue expression levels when compared to control group (p < 0.05 each). Only miRNA-146a skin expression level was significantly higher in patients with multiple lesions (p < 0.001). However, patients with active AA had significantly higher tissue expression levels of the investigated miRNAs than those with inactive disease (P 0.001, 0.009, and 0.001, respectively).

CONCLUSIONS

Investigated miRNAs seem to be role players in AA pathogenesis and may be considered potential indicators of disease activity. However, more research is needed to clarify their accurate role and clinical importance.

Familial Frontal Fibrosing Alopecia: Report of a case and systematic review of the literature

Frontal fibrosing alopecia (FFA) is an emerging disease in Western countries. We present the cases of three sisters who were referred simultaneously to the Department of Dermatology, Hospital Universitario San Cecilio, Granada, Spain, in 2018. All patients suffered from at least partial frontotemporal hairline recession and eyebrow loss. Following trichoscopic examination, the three sisters were diagnosed with FFA. Only one of the sisters agreed to be treated; she was prescribed with topical clobetasol propionate solution and minoxidil and achieved disease control at the three-month follow-up. These patients represent a new case of familial FFA wherein three sisters as well as their mother were affected by FFA. A systematic review found a total of 24 cases of familial FFA, of which this report is the 25th. In the majority of families, only females were affected (88%) while in the remainder both males and females (8%) were affected; there was only one family where only males were affected (4%). The relationship between the affected individuals was predominately between sisters (56%) followed by mother and daughter (32%). The median age was 61 years old (range: 14–88 years) and the duration of the disease ranged between 3–360 months. Family groups of FFA are an infrequently described phenomenon with unknown prevalence.

Scalp and serum profiling of frontal fibrosing alopecia reveals scalp immune and fibrosis dysregulation with no systemic involvement

BACKGROUND

Frontal fibrosing alopecia (FFA) is a progressive, scarring alopecia of the frontotemporal scalp that poses a substantial burden on quality of life. Large-scale global profiling of FFA is lacking, preventing the development of effective therapeutics.

OBJECTIVE

To characterize FFA compared to normal and alopecia areata using broad molecular profiling and to identify biomarkers linked to disease severity.

METHODS

This cross-sectional study assessed 33,118 genes in scalp using RNA sequencing and 350 proteins in serum using OLINK high-throughput proteomics. Disease biomarkers were also correlated with clinical severity and a fibrosis gene set.

RESULTS

Genes differentially expressed in lesional FFA included markers related to Th1 (IFNγ/CXCL9/CXCL10), T-cell activation (CD2/CD3/CCL19/ICOS), fibrosis (CXCR3/FGF14/FGF22/VIM/FN1), T-regulatory (FOXP3/TGFB1/TGFB3), and Janus kinase/JAK (JAK3/STAT1/STAT4) (Fold changes [FCH]>1.5, FDR<.05 for all). Only one protein, ADM, was differentially expressed in FFA serum compared to normal (FCH>1.3, FDR<.05). Significant correlations were found between scalp biomarkers (IL-36RN/IL-25) and FFA severity, as well as between JAK/STAT and fibrosis gene-sets (r>.6; P <.05).

LIMITATIONS

This study was limited by a small sample size and predominantly female FFA patients.

CONCLUSION

Our data characterize FFA as an inflammatory condition limited to scalp, involving Th1/JAK skewing, with associated fibrosis and elevated T-regulatory markers, suggesting the potential for disease reversibility with JAK/STAT inhibition.

Resident Memory T Cells in Autoimmune Skin Diseases

Tissue resident memory T cells (TRM) are a critical component of the immune system, providing the body with an immediate and highly specific response against pathogens re-infecting peripheral tissues. More recently, however, it has been demonstrated that TRM cells also form during autoimmunity. TRM mediated autoimmune diseases are particularly destructive, because unlike foreign antigens, the self-antigens are never cleared, continuously activating self-reactive TRM T cells. In this article, we will focus on how TRMs mediate disease in autoimmune skin conditions, specifically vitiligo, psoriasis, cutaneous lupus erythematosus, alopecia areata and frontal fibrosing alopecia.

Current insight into the functions of microRNAs in common human hair loss disorders: a mini review

Alopecia areata (AA) and Androgenic alopecia (AGA) are the most common multifactorial hair loss disorders that have a serious psychological impact on the affected individuals, while frontal fibrosing alopecia (FFA) is comparatively less common. However, due to the unknown etiology and the effect of many adverse factors, the prognosis of these conditions is challenging to predict. Moreover, no approved therapy has been available to date to prevent or treat these disorders. MicroRNAs (miRNAs) are a group of evolutionary conserved small non-coding RNA molecules with significant roles in the posttranscriptional gene regulation either through mRNA degradation or translational repression. A number of biological processes are controlled by these molecules, including cell growth and differentiation, proliferation, inflammation, immune responses, and apoptosis. Recently, a handful of studies have demonstrated the impact of miRNAs on common hair loss-related disorders; however, the exhaustive molecular mechanisms are still unclear. In this review, we discussed the functional implications of miRNAs in common hair loss-related disorders and addressed their efficacy to be used for theranostic purposes shortly.

Frontal Fibrosing Alopecia: A Review

Frontal fibrosing alopecia is a scarring alopecia, the prevalence of which is increasing worldwide since its first description in 1994. The reason for this emerging epidemic may be a higher exposure to an unknown trigger, although its aethiology and pathogenesis still remain enigmatic. Clinical, trichoscopic, sonographic, and histopathologic findings are allowing clinicians to understand more aspects about this type of cicatricial alopecia. Several treatments have been used in frontal fibrosing alopecia, although the 5-alpha reductase inhibitors seem to be the most promising. The aim of this report is to provide a compilation about the published data regarding frontal fibrosing alopecia in a narrative review.

Frontal Fibrosing Alopecia and Autoimmune Disorders in a Hispanic Female

Frontal fibrosing alopecia (FFA) is a cicatricial alopecia characterized by hairline recession. Multiple autoimmune pathologies have been reported in patients with FFA. Despite the fact that FFA etiology remains unknown, there has been described an association with autoimmune disorders probably caused by an altered activity of cytotoxic CD8 T lymphocytes. Moreover, other autoimmune pathologies develop TH1 and TH17 response. Genetics could be responsible, in part, for the role of multiple simultaneous autoimmune disorders. Herein, we describe a case of a female patient with vitiligo, lichen sclerosus, and autoimmune hypothyroidism who developed a pruritic band-like recession of the frontal hairline. More research is needed in this area since autoimmune events in these patients may not be a mere coincidence.

Isotretinoin for the treatment of facial lichen planopilaris: A new indication for an old drug, a case series study

Despite the little information about the facial papules due to Lichen planopilaris (LPP), we have many cases with facial skin roughness in which histological study has showed LPP. Additionally, in those patients treating for frontal fibrosing alopecia or scalp LPP there was no improvement in facial papules.

Clinical characteristics, trichoscopy, histopathology and treatment outcomes of frontal fibrosing alopecia in an Asian population: A retro-prospective cohort study

Frontal fibrosing alopecia (FFA) is a distinctive lymphocytic scarring alopecia with rapid increase in prevalence. Most FFA series are retrospectively reported from Caucasians with only few from Asians. The objective of this study was to characterize the clinical, trichoscopic and histopathological findings as well as treatment outcomes. This was a retro-prospective cohort study of patients diagnosed with FFA from 1 January 2010 to 1 November 2019. All patients were asked to present for re-examination. Clinical, trichoscopic, histopathological and laboratory data were recorded. A questionnaire was used to investigate hair care, hairstyle and facial skin care compared with age-matched normal controls. Multivariate analysis was performed in order to clarify factors associated with severity. All 58 FFA patients were female, of whom 27.6% were premenopausal, 37.7% had a history of surgical menopause, 13.8% had thyroid diseases, 69% had eyebrow loss and 32.8% facial papules. On physical examination, 10.3% showed linear pattern, 46.6% diffuse pattern and 43.1% pseudo-fringe sign. Concomitant lichen planopilaris was found in 25.9%, lichen planus pigmentosus in 24.1% and female pattern hair loss in 48.3%. The most common trichoscopic characteristics in the frontal hairline were lack of follicular ostia (91.4%), perifollicular scales (79.3%) and perifollicular erythema (63.8%). Up to 90% of patients reported FFA as improved or stable after receiving antiandrogen (finasteride or dutasteride) or antimalarial with topical treatment. Multivariate analyses revealed that facial lentiginous macules and trichoscopic perifollicular erythema at the frontal area were FFA severity-associated factors. "Front puff" Thai hairstyle was associated with FFA, while sunscreens and other cosmetic products were not. In conclusion, diffuse and pseudo-fringe sign pattern are common in Asian FFA. The most common autoimmune systemic comorbidity is thyroid disease, while common concomitant dermatological diseases are female pattern hair loss, lichen planopilaris and lichen planus pigmentosus. Antiandrogens or antimalarial plus topical treatment are the most useful therapy.

Frontal fibrosing alopecia: a disease that remains enigmatic

Frontal fibrosing alopecia (FFA) is recognized to represent a generalized process of inflammatory scarring alopecia. Apart from the classic form affecting the frontal hairline, there are a range of disease manifestations involving loss of eyebrows and of eyelashes, loss of peripheral body hair, fibrosing alopecia in a pattern distribution, facial and extrafacial skin, mucous membrane, and nail involvement. Classic linear, diffuse “zigzag”, pseudo “fringe sign”, androgenetic alopecia-like, cockade-like, ophiasis-like and incomplete patterns are distinguished. The aetiology of FFA remains obscure, but a number of pathogenetic hypotheses and treatments to halt disease progression have been proposed.

Valchlor® in the Treatment of Lichen Planopilaris and Frontal Fibrosing Alopecia: A Single Arm, Open-label, Exploratory Study

Background:

Lichen Planopilaris (LPP) is a lymphocyte-mediated scarring alopecia that frequently is treatment resistance to both topical and systemic therapies.

Aims and Objectives:

The object of this pilot study was to assess the effectiveness of topical mechlorethamine 0.016% gel (Valchlor®) in decreasing disease activity in LPP and the related clinical variant frontal fibrosing alopecia (FAA).

Methods:

Twelve patients with biopsy-proven LPP/FAA who failed prior topical or systemic therapy with active disease were included. Participants applied mechlorethamine 0.016% gel to involved areas daily for 24 weeks. Outcome measures included LPP Activity Index (LPPAI) score, Physician Global Assessment (PGA) score, Dermatology Quality of Life Index (DQLI) score, and phototrichograms assessing follicular counts before and after six months of therapy.

Results:

LPP Activity Index (LPPAI) before and after treatment was significantly different (5.0 before treatment, 2.0 after treatment; p value=0.006). Mean follicular density and follicular units were unchanged during the treatment period.

Conclusion:

Treatment with mechlorethamine 0.016% gel for 24 weeks resulted in statistically significant improvement of LLP/FFA with no change in phototrichogram parameters. Treatment duration was limited by high rate of contact dermatitis. Further investigation to optimize dosing frequency and to assess the role of combination topical therapy is needed.

Risk factors for frontal fibrosing alopecia: A case-control study in a multiracial population

BACKGROUND

Frontal fibrosing alopecia (FFA) is a chronic cicatricial alopecia with unknown etiology and a worldwide rising incidence.

OBJECTIVE

The objective of this study was to evaluate the association of FFA with demographic and exposure factors in a Brazilian multiracial population.

METHODS

A multicenter case-control study was conducted in 11 referral centers throughout Brazil. The study was a case-control study that prospectively recruited 902 participants (451 patients with FFA and 451 sex-matched control individuals). Study participants completed a thorough questionnaire comprising variables grouped as baseline demographics, environmental exposure, diet, hormonal factors, allergies, and hair and skin care.

RESULTS

When adjusted by sex, age, menopause, and skin color, FFA was associated with hair straightening with formalin (odds ratio [OR], 3.18), use of ordinary (nondermatologic) facial soap (OR, 2.09) and facial moisturizer (OR, 1.99), thyroid disorders (OR, 1.69), and rosacea (OR, 2.08). Smokers (OR, 0.33) and users of antiresidue/clarifying shampoo (OR, 0.35) presented a negative association with FFA. There was no association with the use of sunscreen.

LIMITATIONS

Recall bias.

CONCLUSIONS

The association with moisturizers, ordinary facial soap, and hair straightening with formalin and the negative association with antiresidue/clarifying shampoo reinforce the possibility of an exogenous particle triggering FFA.

Frontal fibrosing alopecia and genital Lichen sclerosus: Single-center experience

BACKGROUND

Despite the incidence of Frontal fibrosing alopecia (FFA) has been increasing in last two decades, the pathophysiology and trigger factors of FFA have not been yet fully understood.

AIMS

The aim of this study was to describe epidemiology, clinical and trichoscopic features and comorbidities of FFA patients, in order to improve the understanding of this disease.

PATIENTS/METHODS

A retrospective, observational monocentric study was conducted from 2003 to 2019. Data concerning epidemiology (age, gender, age of menopause, and age of FFA onset), comorbidities, current therapies, localization of FFA (such as frontotemporal hairline, occipital, eyebrow, eyelash, beard, sideburns, and body hair), presence of papules and sign of Lichen planus (LP) at skin, mucosae and/or nail were collected for each patient included.

RESULTS

A total of 119 Caucasian, adult patients (8 men and 111 female) with FFA were enrolled in the study. Cutaneous, mucosal, or nail localization of LP were found in 16% of our subjects. Interestingly, 15 out of 119 subjects (10.61%) were affected by concomitant genital Lichen sclerosus (LS) and 5 out of these 15 patients (4.38%) presented both LS and LP in association with FFA.

CONCLUSION

Considering the high prevalence of LS in FFA patients in our case series, and the frequency of autoimmune comorbidities in both LS and FFA, it is possible to hypothesize an autoimmune process in both conditions. Further studies are needed for a better understanding of the nature of the association between LS and FFA.

Frontal fibrosing alopecia shows robust T helper 1 and Janus kinase 3 skewing

BACKGROUND

Frontal fibrosing alopecia (FFA) is a scarring alopecia with unclear pathogenesis and a progressive course. The disease has a major impact on patients' quality of life and there is a lack of effective treatment to halt disease progression.

METHODS

We profiled lesional and nonlesional scalp biopsies collected in 2017 from patients with FFA (n = 12) compared with scalp biopsies from patients with alopecia areata (AA) (n = 8) and controls (n = 8) to evaluate gene and protein expression, including the primary outcome (CXCL9). We determined significant differences between biomarkers using a two-sided Student's t-test adjusting P-values by false discovery rate.

RESULTS

Significant increases were seen in CD8+ cytotoxic T cells, CD11c+ dendritic cells, CD103+ and CD69+ tissue-resident memory T cells in FFA and AA vs. control scalp (P < 0·05), with corresponding significantly upregulated granzyme B mRNA, particularly in FFA (P < 0·01). In AA, cellular infiltrates were primarily concentrated at the bulb, while in FFA these were mainly localized at the bulge. FFA demonstrated significant upregulation of T helper 1/intereferon (IFN) (IFN-γ, CXCL9/CXCL10), the Janus kinase/signal transducers and activators of transcription (JAK-STAT) pathway (STAT1, JAK3) and fibrosis-related products (vimentin, fibronectin; P < 0·05), with no concomitant downregulation of hair keratins and the T-regulatory marker, forkhead box P3, which were decreased in AA. The stem cell markers CD200 and K15 demonstrated significantly reduced expression only in FFA (P < 0·05).

CONCLUSIONS

These data suggest that follicular damage and loss of stem cells in FFA may be mediated through immune attack in the bulge region, with secondary fibrosis and reduced but still detectable stem cells. JAK/STAT-targeting treatments may be able to prevent permanent follicular destruction and fibrosis in early disease stages.

A Novel Atypical Presentation of Frontal Fibrosing Alopecia Involving the Frontoparietal Scalp

Frontal fibrosing alopecia (FFA) is a progressive scarring alopecia of unknown etiology that classically presents with a band of hair loss along the frontotemporal scalp. We report a case of FFA involving a band of alopecia along the frontotemporal scalp extending into 2 symmetrical triangles along the parietal scalp reminiscent of the Greek letter upsilon (υ). Trichoscopy demonstrated loss of follicular ostia and peripilar casts. Histology demonstrated altered follicular architecture with decreased follicular density and focal perifollicular fibrosis with a lichenoid infiltrate. Both the trichoscopy and histology support a diagnosis of FFA.

Profiling the human hair follicle immune system in lichen planopilaris and frontal fibrosing alopecia: can macrophage polarization differentiate these two conditions microscopically?

BACKGROUND

Frontal fibrosing alopecia (FFA) is traditionally regarded as a variant of lichen planopilaris (LPP) based on histological features. Distinct clinical presentation, demographics and epidemiology suggest that differing pathogenic factors determine the final phenotype.

OBJECTIVES

To map the hair follicle immune system in LPP and FFA by systematically comparing key inflammatory markers in defined hair follicle compartments.

METHODS

Lesional scalp biopsies from LPP and FFA and healthy controls were stained with the following immunohistochemical markers: CD1a and CD209, CD4, CD8, CD56, CD68, CD123, CXCR3, forkhead box (FOX)P3, mast cell tryptase and cKit. Macrophage polarization was explored using CD206, CD163, CD86, receptor for advanced glycation end products (RAGE), interleukin (IL)-4 and IL-13 on paired lesional and nonlesional LPP and FFA samples.

RESULTS

Increased numbers of CD8⁺ , CXCR3⁺ and FOXP3⁺ T cells and CD68⁺ macrophages were identified in the distal hair follicle epithelium and perifollicular mesenchyme in both LPP and FFA compared with controls. In both LPP and FFA, total and degranulated mast cells and CD123⁺ plasmacytoid dendritic cells were increased in the perifollicular mesenchyme adjacent to the bulge and infundibulum, whereas numbers of CD1a⁺ and CD209⁺ dendritic cells were significantly reduced in the infundibulum connective tissue sheath. However, only with CD68 staining was a significant difference between LPP and FFA identified, with greater numbers of CD68⁺ cells in LPP samples. Furthermore, the identified macrophage polarization markers downregulated CD86 and upregulated CD163 and IL-4 expression in lesional LPP compared with FFA samples.

CONCLUSIONS

This comparative immunopathological analysis is the first to profile systematically the hair follicle immune system in LPP and FFA. Our analysis highlights a potential role of macrophages in disease pathobiology and suggests that macrophage polarization may differ between LPP and FFA, allowing microscopic differentiation. Linked Comment: Kinoshita-Ise. Br J Dermatol 2020; 183:419-420.

Clinical-histopathological profile of the frontal fibrosing alopecia: a retrospective study of 16 cases of a university hospital

BACKGROUND

Frontal fibrosing alopecia is a condition of unknown origin, histologically similar to classic lichen planopilaris and generally observed in postmenopausal women with alopecia of the frontal-temporal hairline.

OBJECTIVES

To describe the clinical, dermatoscopic, and histopathological characteristics and the treatment used in patients who have frontal fibrosing alopecia at the Alopecia Outpatient Clinic in a university hospital.

METHODS

Retrospective descriptive study performed by reviewing medical charts and biopsies of the scalp.

RESULTS

Sixteen patients were analyzed, all of them female, 93.75% of them postmenopausal, and 56.25% brown-skinned. All had frontal alopecia (100%), followed by temporal alopecia (87.5%) and madarosis (87.5%). On dermatoscopy, perifollicular erythema and tubular scales were found as a sign of disease activity. Of the patients, 68.75% had associated autoimmune diseases, including lupus, thyroid disease and vitiligo. Of the 13 biopsies from 8 patients, 10 showed microscopic aspects compatible with frontal fibrosing alopecia. Laboratory tests did not show major abnormalities and minoxidil was the most used treatment.

STUDY LIMITATION

Data collection limited by the study's retrospective design associated to flaws while filling in the medical charts and absence in standards to the collection and processing of the pathology and histopathological examination.

CONCLUSIONS

A demographical, clinical, and histopathological description of 16 patients diagnosed with frontal fibrosing alopecia, which remains a challenging disease, of unknown origin, and frequently associated with autoimmune diseases. This study reinforces literary findings. However, more research is needed to establish the pathogenesis and effective treatments.

Cholesterol homeostasis: Links to hair follicle biology and hair disorders

Lipids and lipid metabolism are critical factors in hair follicle (HF) biology, and cholesterol has long been suspected of influencing hair growth. Altered cholesterol homeostasis is involved in the pathogenesis of primary cicatricial alopecia, mutations in a cholesterol transporter are associated with congenital hypertrichosis, and dyslipidaemia has been linked to androgenic alopecia. The underlying molecular mechanisms by which cholesterol influences pathways involved in proliferation and differentiation within HF cell populations remain largely unknown. As such, expanding our knowledge of the role for cholesterol in regulating these processes is likely to provide new leads in the development of treatments for disorders of hair growth and cycling. This review describes the current state of knowledge with respect to cholesterol homeostasis in the HF along with known and putative links to hair pathologies.

Frontal Fibrosing Alopecia: An Update on Pathogenesis, Diagnosis, and Treatment

Frontal fibrosing alopecia (FFA), first described by Kossard in the early 1990s, is a form of primary lymphocytic cicatricial alopecia characterized by selective involvement of the frontotemporal hairline and eyebrows. Since the original description, an increasing number of cases have been reported worldwide and the clinical aspects of the disease have been better characterized. However, the pathogenesis is still unknown and several hypotheses have been made about possible triggering factors, including hormones, neurogenic inflammation, smoking, UV filters, and ingredients in leave-on facial products. A genetic basis has also been hypothesized as the disease can occur in siblings and members of the same family. Besides its pathogenesis, research is also focused on treatment; FFA is a chronic condition and at present there is no validated or approved treatment for this disorder. Commonly prescribed topical treatments include corticosteroids, minoxidil, and calcineurin inhibitors. Systemic treatments include 5α-reductase inhibitors, hydroxychloroquine, and retinoids. Intralesional triamcinolone acetonide is also utilized, especially for the eyebrows. Other possible treatments include pioglitazone, naltrexone, tofacitinib, and lasers.

[Postmenopausal lichen planopilaris also known as fibrosing frontotemporal alopecia Kossard : An evidence-oriented practical guide to treatment from the University of the Saarland, Hair Research Center of the Dr. Rolf M. Schwiete Foundation]

Postmenopausal lichen planopilaris (PLPP), also known as fibrosing frontotemporal alopecia Kossard (FFAK), is a not uncommon inflammatory scalp disease affecting approximately 5% of patients at specialized hair centers. The overall incidence of sporadic occurrence is believed to be just under 1% in the older, predominantly female, general population. Since the disease is often undiagnosed, it is statistically likely to be underrepresented. It especially occurs in postmenopausal women who are in the 6th and 7th decade of life (90%), but also in about 10% of premenopausal women, and in men it is documented only in isolated cases. The result is a permanent scarring hair loss accentuated at the front hairline with backward movement towards the neck mostly accompanied by a typical loss of the eyebrows. The disease therefore often leads to significant mental distress and social anxiety in those affected. This is the basis for a compelling need to develop evidence-based therapeutic concepts. While numerous retrospective case series have characterized the phenomenology of FFAK very well, to date there are no randomized controlled trials on evidence-based therapy. Here, we present the Homburger Evidence-Oriented Therapy Algorithm, which is oriented along the available case series evidence: It may (1) serve as a therapy guide for practice and (2) can be used as a basis for working out reliable data based on study evidence. The article contains detailed practical information on photo documentation, biopsy and histological processing up to the practical implementation of, for example, intralesional steroid therapy as well as information on selection criteria for suitable systemic therapies.

Medical therapy for frontal fibrosing alopecia: A review and clinical approach

BACKGROUND

Guidelines for the treatment of frontal fibrosing alopecia (FFA) are limited, and the literature on treatment modalities consists mostly of case reports and cohort studies.

OBJECTIVES

In this review, we sought to assess the response of medical therapy for FFA and propose a clinical approach to management.

METHODS

A literature search for "frontal fibrosing alopecia" on PubMed returned 270 items. In this review, only studies with treatment regimens and reported outcomes were considered. The majority of studies found were case reports and retrospective cohort studies. Response to therapy was assessed by reported ability to slow or arrest hair loss.

RESULTS

Intralesional steroids and 5α-reductase inhibitors were the most commonly used therapies with the most positive treatment responses (88%, 181/204 for intralesional steroids and 88%, 158/180 for 5α-reductase inhibitors). Oral prednisone was seldom used and only temporarily delayed rapid hair loss. Other therapies evaluated included topical steroids, antibiotics, pioglitazone, systemic retinoids, and hair transplantation.

LIMITATIONS

Lack of placebo control studies and uniform outcome measures.

CONCLUSION

The natural course of FFA is variable. Recession of the frontal hairline might stabilize regardless of treatment. However, early intervention is encouraged in active disease because hair loss is presumed permanent and treatment could modify the disease course.

Genome-wide association study in frontal fibrosing alopecia identifies four susceptibility loci including HLA-B*07:02

Frontal fibrosing alopecia (FFA) is a recently described inflammatory and scarring type of hair loss affecting almost exclusively women. Despite a dramatic recent increase in incidence the aetiopathogenesis of FFA remains unknown. We undertake genome-wide association studies in females from a UK cohort, comprising 844 cases and 3,760 controls, a Spanish cohort of 172 cases and 385 controls, and perform statistical meta-analysis. We observe genome-wide significant association with FFA at four genomic loci: 2p22.2, 6p21.1, 8q24.22 and 15q2.1. Within the 6p21.1 locus, fine-mapping indicates that the association is driven by the HLA-B*07:02 allele. At 2p22.1, we implicate a putative causal missense variant in CYP1B1, encoding the homonymous xenobiotic- and hormone-processing enzyme. Transcriptomic analysis of affected scalp tissue highlights overrepresentation of transcripts encoding components of innate and adaptive immune response pathways. These findings provide insight into disease pathogenesis and characterise FFA as a genetically predisposed immuno-inflammatory disorder driven by HLA-B*07:02.

Frontal fibrosing alopecia (FFA) features lichenoid cutaneous inflammation and scarring hair loss. Here, Tziotzios et al. identify four genetic loci associated with FFA by GWAS followed by Bayesian fine-mapping, co-localisation and HLA imputation which highlights HLA-B*07:02 as a risk factor.

Use of trichoscopy for the diagnosis of alopecia areata coexisting with primary scarring alopecia in a female hair loss patient

Despite patchy hair loss being typically observed in alopecia areata (AA), similar lesions can be seen in other forms of alopecia and the diagnosis is sometimes challenging. Of note, patchy primary scarring alopecia (SA) needs to be clearly distinguished from AA as SA can leave permanent hair loss. Herein, we report a previously unreported case of AA coexisting with SA successfully diagnosed by detailed trichoscopic investigation. A 42-year-old woman visited us with patchy hair loss lesions on the scalp. On physical examination, alopecic lesions sized up to 2 cm in diameter were observed in the right temporal and parietal regions. A gentle hair pull test collected dystrophic anagen hairs from some patches. Trichoscopy detected tapering hairs and black dots. The diagnosis of AA was made. However, some reddish patches were totally hair pull test negative, urging us to further evaluate the remaining lesions. Additional trichoscopic investigation revealed the disappearance of follicular ostia and the presence of a white and milky-red area and peripilar scales, suggestive of SA. In histology, the clinically AA lesion showed peribulbar cell infiltration, while the potentially SA lesion demonstrated inflammatory cell infiltration around the isthmus and the decrease in hair follicles, some of which were replaced by fibrotic tissue. The final diagnosis of AA coexisting with SA was made. Intralesional corticosteroid injection improved AA but not SA. These findings emphasize the need for thorough trichoscopic examination for accurate diagnoses of rare hair loss conditions.

Lichen planus and lichenoid dermatoses: Clinical overview and molecular basis

Deriving from the Greek word λειχήν for "tree moss" and the Latin word planus for "planar," lichen planus is a relatively uncommon and heterogeneous cutaneous disorder that typically develops in middle-aged adults. Despite the significant clinical burden associated with the disorder, little well-conducted molecular research has been undertaken, possibly because of heterogeneity impeding consistent and confident phenotyping. The multiple variants of lichenoid disease bear overlapping clinical and pathologic features despite manifesting as distinct clinical disorders. The first article in this 2-part continuing medical education series provides a comprehensive overview of the clinical and pathologic characteristics of cutaneous lichenoid dermatoses and links these manifestations to recent advances in our understanding of the underlying pathobiology of such diseases.

A proposed mechanism for central centrifugal cicatricial alopecia

Central centrifugal cicatricial alopecia (CCCA) has an unknown mechanism. Analyzing other scarring diseases (lichen planopilaris, fibrotic kidney disease and scleroderma) may help to clarify the mechanism of scarring in CCCA. These diseases were chosen for comparison due to either their location of disease (skin or scalp specifically), or prominence in patients of African descent. Genetics, possible triggers, an autoimmune lymphocytic response, and epithelial to mesenchymal transition are potentially involved. Possible common pathways in scarring diseases and a better understanding of the CCCA mechanism will lead to further research into the pathogenesis and potential treatments of CCCA.

Cicatricial Alopecia in Identical Twin Lumbee Native American Women

Central centrifugal cicatricial alopecia (CCCA) has become a well-known entity occurring mainly in African-American women, but is rarely encountered in other populations. This report describes a set of identical twin Lumbee Indian women, both developing cicatricial alopecia, with one sister diagnosed with CCCA overlap with lichen planopilaris and the other with CCCA. The Lumbee Tribe is a federally recognized group of Native Americans who reside in North Carolina. Lumbee Indians have shown an increased incidence of several metabolic and neurologic diseases but cicatricial alopecia has never been an identified associated disease of the Lumbee. Thus far, no published studies have shown cicatricial alopecia as occurring in identical twins or in Native Americans. This case report discusses the issues of haircare practices and genetics in contributing to cicatricial alopecia.

Lichen planopilaris and frontal fibrosing alopecia cannot be differentiated by histopathology

BACKGROUND

Lichen planopilaris (LPP) and frontal fibrosing alopecia (FFA) represent 2 entities that cause primary cicatricial alopecia. These entities are clinically different; nevertheless, the literature suggests that FFA represents a form of LPP. The main argument in support of this hypothesis is that previous studies comparing the histologic findings have not found obvious differences between these diseases.

METHODS

Our objective was to more critically compare and contrast 20 histologic findings of these diseases in a large number of patients in order to determine any significant histologic differences between LPP and FFA.

RESULTS

We found 3 parameters that were statistically different, namely the presence of terminal catagen-telogen hairs (50% FFA vs 23.5% LPP; P = .020); a severe perifollicular inflammatory infiltrate (29.4% LPP vs 4.6% FFA; P = .010) and a zone of concentric lamellar fibroplasia (85.3% LPP vs 63.6% FFA; P = .041).

CONCLUSIONS

Although a few histologic features differ between FFA and LPP, we believe that these differences are too subtle or non-specific to distinguish between them with confidence. Therefore, clinical correlation is essential to establish the diagnosis.

Development of Frontal Fibrosing Alopecia with a History of Alopecia Areata

Frontal fibrosing alopecia (FFA), a scarring type of alopecia, developed in two patients with a history of alopecia areata (AA). Both patients had biopsies to confirm this interesting series of pathology. Etiology and pathogenesis of this AA-to-FFA sequence will be discussed.

A Retrospective Analysis of Efficacy and Safety of Intralesional Triamcinolone Injections in the Treatment of Frontal Fibrosing Alopecia Either as Monotherapy or as a Concomitant Therapy

Context:

Frontal fibrosing alopecia (FFA) is a primary cicatricial alopecia characterized by progressive recession of frontal, and often temporoparietal, hairline mainly in postmenopausal women. Currently, there are no guidelines or proposed evidence-based treatment for FFA.

Aims:

The aim of this study was to retrospectively evaluate the effect and safety of intralesional triamcinolone acetonide injections (ITAIs) either as monotherapy or as concomitant treatment in the management of hairline recession in FFA.

Subjects and Methods:

All patients with FFA, who visited our specialist hair clinic from July 2012 to October 2016 and were treated with ITAI either as monotherapy or as concomitant treatment, were enrolled in our study. Measurements were performed from five different points on the scalp. The analysis of data included demographics, associated symptoms, clinical and dermoscopic findings, comorbidities, family history of FFA, concomitant medication, treatment outcome, and recording of adverse events.

Statistical Analysis:

Statistical analysis was performed using the Statistical Package for the Social Sciences, version 22.0.

Results:

A total of 40 patients, all females were enrolled in our study. The mean age of the patients was 65.88 ± 8.18 whereas the mean age of the diagnosis was 61.24 ± 7.4. A total of 39 patients were treated with a combination of treatments, including ITAI, and only one with ITAI as monotherapy. There was a halting of the progress of the disease, and no significant adverse events were noted, apart from mild pain.

Conclusions:

A halting in the progression of FFA was achieved, with unremarkable adverse events. ITAI could serve as an effective and safe option for the treatment of FFA, although difficult to assess it as monotherapy. Further randomized controlled trials are needed to evaluate its efficacy and safety as the sole treatment in the management of FFA.

Hormonal and Gynecological Risk Factors in Frontal Fibrosing Alopecia: A Case-Control Study

Introduction

Frontal fibrosing alopecia (FFA) is a condition that likely involves an interplay of autoimmune, hormonal, and environmental factors in its pathogenesis. There is a lack of comparative studies demonstrating the presence of hormonal background differences in FFA patients compared to the general population.

Materials and Methods

A single-center case-control study was designed, including 104 female FFA patients and 208 controls. Patients and controls were interviewed, and extensive data regarding their gynecological and hormonal background were recorded.

Results

One hundred four cases and 208 age-matched controls were included in the study. A significant difference of 2 years in the age of menopause was detected with a consistent mean increase in fertile life for the control group of 1.7 years. After the multivariate analysis, we found previous intake of tamoxifen to be a risk factor for the development of FFA (OR 14.89). The only protective factor identified was the previous use of an intrauterine device (IUD) (OR 0.22).

Conclusions

An earlier menopause and tamoxifen intake might promote or maintain FFA, while the use of an IUD might protect from developing FFA. Our results support the previously proposed hypothesis of an underlying hormonal mechanism in the etiopathogenesis of FFA and point out low-estrogen environments as an ideal condition for FFA development.

Epithelial-to-Mesenchymal Stem Cell Transition in a Human Organ: Lessons from Lichen Planopilaris

Epithelial-to-mesenchymal transition (EMT) is critical for embryonic development and wound healing, and occurs in fibrotic disease and carcinoma. Here, we show that EMT also occurs within the bulge, the epithelial stem cell (eSC) niche of human scalp hair follicles, during the inflammatory permanent alopecia, lichen planopilaris. We show that a molecular EMT signature can be experimentally induced in healthy human eSCs in situ by antagonizing E-cadherin, combined with transforming growth factor-β1, epidermal growth factor, and IFN-γ administration, which to our knowledge has not been reported previously. Moreover, induction of EMT within primary human eSCs can be prevented and even partially reversed ex vivo by peroxisome proliferator-activated receptor-γ agonists, likely through suppression of the transforming growth factor-β signaling pathway. Furthermore, we show that peroxisome proliferator-activated receptor-γ agonists also attenuates the EMT signature even in lesional lichen planopilaris hair follicles ex vivo. We introduce lichen planopilaris as a model disease for pathological EMT in human adult eSCs, report a preclinical assay for therapeutically manipulating eSC EMT within a healthy human (mini-)organ, and show that peroxisome proliferator-activated receptor-γ agonists are promising agents for suppressing and partially reversing EMT in human hair follicles eSCs ex vivo, including in lichen planopilaris.