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

Refractory alopecia areata with single hairs imitating frontal fibrosing alopecia: a prospective observational study

BACKGROUND

Lonely hair sign is considered as a clue to the diagnosis of frontal fibrosing alopecia (FFA).

OBJECTIVE

To report an undescribed variant of alopecia areata (AA) with which the patient developed single hairs and other features similar to FFA and to determine the underlying mechanism.

METHODS

We conducted a prospective observational study in patients who presented with receding hairline and single hairs, evaluating the clinical, trichoscopic, and histological features and their correlation. Immunochemistry studies were performed to describe the microenvironment.

RESULTS

Eighteen patients were enrolled in the study. Despite the similarity to FFA clinically, these patients showed different histopathology which revealed a normal number of pilosebaceous units, one anagen hair in one or more pilosebaceous units, and others in telogen stage, consistent with single hairs under the naked eye or under trichoscopy. The severity of the hair loss assessed by SALT was no more than 50, but the response to conventional therapy was poor.

CONCLUSIONS

This study reports a unique variant of AA. The pathological basis is an increase in the telogen hair follicles, with one anagen hair in one or more pilosebaceous units. Minimal inflammation consisting of CD3+ T lymphocytes and mast cells was demonstrated in the microenvironment.

Controlling Hair Loss by Regulating Apoptosis in Hair Follicles: A Comprehensive Overview

Apoptosis is a physiological process that occurs in all cell types of the human body, and it profoundly changes the fate of hair by affecting hair follicle cells. This review outlines the cellular changes, intrinsic biochemical characteristics, and mechanisms underlying apoptosis and summarizes the hair follicle life cycle, including development, cycle stages, and corresponding cellular changes. Finally, the relationship between apoptosis and the hair cycle is discussed and the significance of apoptosis in hair loss conditions and drug treatments is highlighted. Apoptosis induces cellular changes and exhibits distinctive properties through intricate signaling pathways. Hair follicles undergo cyclic periods of growth, regression, and dormancy. Apoptosis is closely correlated with the regression phase by triggering hair follicle cell death and shedding. Regulation of apoptosis in hair follicles plays an essential role in hair loss due to maladies and drug treatments. Mitigating apoptosis can enhance hair growth and minimize hair loss. A comprehensive understanding of the correlation between apoptosis and the hair cycle can facilitate the development of novel treatments to prevent hair loss and stimulate hair regeneration.

A Retrospective Study of Frontal Fibrosing Alopecia from North-East India

Background

Frontal fibrosing alopecia (FFA) is an important cause of scarring alopecia seen mostly in post-menopausal women but sometimes in pre-menopausal women and men. Although considered a variant of lichen planopilaris due to its histopathological characteristics, it has distinct clinical features and associations, which make it a unique entity. We hereby report a series of patients with FFA from North-East India.

Aims and Objective

This study aimed to analyse the clinical and histopathological characteristics of FFA.

Materials and Methods

We retrospectively analysed clinical records and histopathological features of FFA cases diagnosed in the Dermatology Outpatient Department from April 2013 to February 2023.

Results

A total of 21 patients, who were diagnosed with FFA from April 2013 to February 2023, were analysed. Of these, 19 patients were female, with a male-to-female ratio of 9.5:1. The mean age of study population was 48.33 years. The majority of the patients were from the post-menopausal age group (15/19 females, 78.94%). Lichen planus pigmentosus (6, 28.57%) was the most commonly associated disease, followed by androgenetic alopecia and lichen planopilaris (2 each, 9.52%). The main histological features noted were perifollicular lymphocytic infiltrate in 18 (85.71%), followed by hydropic degeneration of basal follicular keratinocytes in 15 (71.42%) and melanin incontinence in 14 (66.66%) patients.

Conclusion

Our study is the first study from North-East India focusing on the clinical presentation and histopathological characteristics of FFA. Furthermore, with respect to the recent development in FFA, our study attempted to determine the clinical significance of the proposed criteria for the diagnosis of FFA patients by Tolkachjov et al. (2018), viz. International FFA Cooperative Group Criteria (2021).

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

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

Protein profiling of forehead epidermal corneocytes distinguishes frontal fibrosing from androgenetic alopecia

Protein profiling offers an effective approach to characterizing how far epidermis departs from normal in disease states. The present pilot investigation tested the hypothesis that protein expression in epidermal corneocytes is perturbed in the forehead of subjects exhibiting frontal fibrosing alopecia. To this end, samples were collected by tape stripping from subjects diagnosed with this condition and compared to those from asymptomatic control subjects and from those exhibiting androgenetic alopecia. Unlike the latter, which exhibited only 3 proteins significantly different from controls in expression level, forehead samples from frontal fibrosing alopecia subjects displayed 72 proteins significantly different from controls, nearly two-thirds having lower expression. The results demonstrate frontal fibrosing alopecia exhibits altered corneocyte protein expression in epidermis beyond the scalp, indicative of a systemic condition. They also provide a basis for quantitative measures of departure from normal by assaying forehead epidermis, useful in monitoring response to treatment while avoiding invasive biopsy.