Trichoscopy of primary cicatricial alopecias: an updated review

Trichoscopy - a valuable tool for identifying conditions mimicking androgenetic alopecia

Androgenetic alopecia (AGA) is the most prevalent type of hair loss in women and men. Recently, a European consensus group published guidelines for the diagnostic evaluation of AGA in men, women, and adolescents. This S1 guideline presents expert opinion-based recommendations for gender-dependent steps in the diagnostic procedure, which can easily be implemented in the daily clinical routine. For diagnosing AGA, detailed anamnesis and objective learning are not enough because there are several conditions mimicking this disease. Trichoscopy can be considered an important, non-invasive tool for diagnosing hair and scalp disorders that may have similar clinical signs to AGA.

Diagnoseverzögerung, komorbide Hidradenitis suppurativa und die prognostische Bedeutung bakterieller Kulturen bei Folliculitis decalvans: eine Kohortenstudie

Hintergrund

Folliculitis decalvans (FD) ist eine primäre neutrophile vernarbende Alopezie, die häufig zu irreversiblem Haarverlust führt. Daten zu Epidemiologie, klinischen Merkmalen, Folgen und prognostischen Faktoren sind nur eingeschränkt verfügbar.

Ziel

Die Beurteilung einer Patientenkohorte mit FD sowie die Charakterisierung schwerer Krankheitsverläufe und prognostischer Faktoren, die eine Remission verhindern.

Patienten und Methoden

Diese retrospektive Kohortenstudie umfasste 192 Patienten, bei denen zwischen 2010 und 2020 an einem tertiären Zentrum eine FD diagnostiziert und die mindestens sechs Monate nachverfolgt wurden.

Ergebnisse

Die Diagnose wurde im Mittel um 22,2 (± 29,7) Monate verzögert gestellt. Komorbide Erkrankungen mit Okklusion der Haarfollikel waren häufig. In 45,6% der Fälle waren Bakterienkulturen positiv, am häufigsten mit Staphylococcus (S.) aureus. Schwere Krankheitsverläufe waren mit komorbider Hidradenitis suppurativa und positiver Bakterienkultur, insbesondere S. aureus, assoziiert. Bei 50,7% der Patienten kam es zu vollständiger Remission: Bei 32% innerhalb der ersten sechs Monate der Behandlung und bei 18,7% während der Nachkontrolle. Rezidive waren häufig. Negative Prognosefaktoren bezüglich der Remission waren jüngeres Alter und positive Bakterienkultur.

Schlussfolgerungen

Es besteht Bedarf hinsichtlich der Ausbildung von Dermatologen, um die Diagnoseverzögerung zu reduzieren. Das Screening von FD‐Patienten auf komorbide Hidradenitis suppurativa und Bakterienkulturen sind wichtig für die Behandlungsplanung.

Diagnostic delay, comorbid hidradenitis suppurativa and the prognostic value of bacterial culture in folliculitis decalvans: A cohort study

BACKGROUND

Folliculitis decalvans (FD) is a type of primary neutrophilic cicatricial alopecia often leading to irreversible hair loss. Data on its epidemiology, clinical features, outcomes, and prognostic factors are limited.

OBJECTIVE

To evaluate a cohort of patients with FD and identify characteristics of severe disease and prognostic factors which impede remission.

PATIENTS AND METHODS

This retrospective cohort study included 192 patients diagnosed with FD and followed for at least six months at a tertiary center between 2010 and 2020.

RESULTS

There was a diagnostic delay averaging 22.2 (± 29.7) months. Comorbid follicular occlusion disorders were common. Bacterial cultures were positive in 45.6% of the cases, with Staphylococcus (S.) aureus being the most common pathogen. Severe disease was associated with comorbid hidradenitis suppurativa and a positive bacterial culture, particularly S. aureus. 50.7% of patients experienced complete remission: 32% within the first six months of treatment and 18.7% later during follow-up. Relapses were frequent. Negative prognostic factors for achieving remission included younger age and a positive bacterial culture.

CONCLUSIONS

There is a need for the education of dermatologists to reduce the diagnostic delay. Screening FD patients for comorbid hidradenitis suppurativa and obtaining bacterial cultures is important for treatment planning.

The dermatoscope in the hair clinic: Trichoscopy of scarring and nonscarring alopecia

Trichoscopy is currently regarded as an essential part of the hair loss consultation. It allows visualization of morphologic structures that are not obvious to the naked eye, including peri- and interfollicular skin surface abnormalities and changes to hair shaft thickness and shape. In this paper, we aim to discuss current knowledge on trichoscopy of the most common forms of scarring and nonscarring alopecias.

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.

[Translated article] Trichoscopy: An Update

Trichoscopy is a simple, noninvasive office procedure that can be performed using a handheld or digital dermatoscope. This tool has gained popularity in recent years, because it provides useful diagnostic information for hair loss and scalp disorders by enabling the visualization and identification of distinctive signs and structures. We present an updated review of the trichoscopic features described for some of the most common hair loss disorders seen in clinical practice. Dermatologists should be familiar with these helpful features, as they can significantly aid the diagnosis and follow-up of numerous conditions, such as alopecia areata, trichotillomania, and frontal fibrosing alopecia.

Trichoscopy: An Update

Trichoscopy is a simple, noninvasive office procedure that can be performed using a handheld or digital dermatoscope. This tool has gained popularity in recent years, because it provides useful diagnostic information for hair loss and scalp disorders by enabling the visualization and identification of distinctive signs and structures. We present an updated review of the trichoscopic features described for some of the most common hair loss disorders seen in clinical practice. Dermatologists should be familiar with these helpful features, as they can significantly aid the diagnosis and follow-up of numerous conditions, such as alopecia areata, trichotillomania, and fibrosing frontal alopecia.

Primary cicatricial alopecia: Recent advances in evaluation and diagnosis based on trichoscopic and histopathological observation, including overlapping and specific features

Primary cicatricial alopecia (PCA) is a form of alopecia in which inflammatory cells target follicles, including the bulge region containing follicular stem cells, leading to permanent alopecia. New classifications of PCA subtypes have recently been proposed, including those that account for novel trichoscopic and histopathological features of PCA, enabling greater precision in the evaluation and diagnosis of this condition. Nonetheless, diagnosis remains challenging clinically and histopathologically because the etiology of PCA is multifactorial. Inconsistent use of terminology, overlapping disease concepts, and changes in the clinical or histopathological severity of inflammation in the disease course in the same patient also make diagnosis quite challenging. The present study comprehensively reviews recent progress in diagnostic techniques, including the use of clinical, trichoscopic, and histopathological features, in evaluating each PCA subtype, containing overlapping and specific features. Elucidating the features of PCA, including those that are common to multiple subtypes as well as specific to each in both early and advanced-stage lesions, is important for accurate diagnosis. Improving the evaluation and treatment of this disease depends on having a broader clinical understanding that takes into account not only the features of the disease at a given point in time, but also the changes that occur during the entire disease course.

Dermatoscopy

The dermatoscope has gained tremendous popularity among dermatologists as an adjunctive tool to better visualize subsurface structures and identify patterns that may improve the diagnosis of a wide range of skin diseases. Initially, the pigmented lesion experts who were the early adopters promoted the use of the dermatoscope to increase diagnostic accuracy of early melanomas and decrease the harvesting of benign lesions. With current near universal adoption of the diagnostic technique by dermatologists, the dermatoscope is now employed to help identify a wide variety of inflammatory, infectious, and vascular conditions of the skin, hair, and nails, resulting in the emergence of several branches of dermatoscopy-inflammoscopy, trichoscopy, onychoscopy, and entodermoscopy. The future of dermatoscopy will involve incorporation of artificial intelligence that will make the assessment process increasingly objective, more accurate, and universally available. Despite the wide acceptance and adoption of dermatoscopy, the overall impact of its widespread use still remains unclear, whether it has decreased biopsy rates of benign lesions, reduced health care costs, or improved patient outcomes.

Update on trichoscopy: Integration of the terminology by systematic approach and a proposal of a diagnostic flowchart

Trichoscopy represents a non-invasive diagnostic modality widely used in daily practice. Despite the common perception that this technique has been fairly established, some key issues remain to be addressed. Complexity and inconsistency in terminology in past literature are likely to confuse investigators when they are recording, reporting, and retrieving the findings. In addition, a diagnostic algorithm adopting sufficiently integrated and updated findings is not readily available. By adopting a systematic review approach, this review attempted to redefine major trichoscopic findings and integrate their synonyms individually into the most frequently used terms besides identifying and discussing terms which potentially cause confusion. The findings are categorized into five subgroups: hair shaft, follicular, perifollicular, scalp findings, and hair distribution pattern abnormalities. The calculation of sensitivities and positive predictive values of such redefined findings was conducted by reviewing the descriptions in the past literature on major hair diseases, including alopecia areata, androgenetic alopecia/female pattern hair loss, telogen effluvium, trichotillomania, lichen planopilaris, frontal fibrosing alopecia, central centrifugal cicatricial alopecia, discoid lupus erythematosus, folliculitis decalvans, tinea capitis, and dissecting cellulitis, to confirm the diagnostically meaningful findings for representative diseases. This attempt redefined, for instance, yellow dots, short vellus hairs, exclamation mark hairs, black dots, and broken hairs as the findings of diagnostic significance for alopecia areata and hair diameter diversity, peripilar sign, and focal atrichia for androgenetic alopecia/female pattern hair loss. An updated diagnostic flowchart is proposed with the instructions to maximize its usefulness. Current limitations and future perspectives of trichoscopy as well as other emerging non-invasive diagnostic modalities for hair diseases are also discussed.

Assessment, reliability, and validity of trichoscopy in the evaluation of alopecia in women

Background

Alopecia in women is generally difficult to diagnose clinically. Trichoscopy may help make the correct diagnosis in doubtful cases.

Objective

The aims of the study were to assess the trichoscopic features of different types of alopecia in women, the reliability of trichoscopy vis-à-vis clinical findings, and the validity of trichoscopy in cases with a doubtful clinical diagnosis.

Methods

A hospital-based observational, cross-sectional study was carried out on female patients with alopecia. A trichoscopic diagnosis was made and correlated with a clinical diagnosis. The validity of trichoscopy in doubtful cases was evaluated by reporting the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic value.

Results

On trichoscopy, increased hair diameter diversity > 20%, single-hair follicular unit, vellus hair, peripilar sign, and focal atrichia were commonly seen in female pattern hair loss. In telogen effluvium, there was a scarceness of specific findings. In cicatricial alopecias, loss of follicular ostia, erythema, white macules, blue-gray dots, white dots, tufted hair, and keratotic follicular plugging were observed. A good agreement between trichoscopy and clinical diagnosis was found (Cohen’s Kappa = 0.824; 95% confidence interval, 0.756–0.892). The validity of trichoscopy in doubtful cases was evaluated using the validity parameters, which were high in all alopecias.

Limitations

Histopathology testing was not done in all patients.

Conclusion

Trichoscopy helped reach a definitive diagnosis in patients in whom the clinical diagnosis was doubtful. Thus, trichoscopy is a sensitive and specific investigation that can be valuable in women with alopecia.

Pili Torti: A Feature of Numerous Congenital and Acquired Conditions

Pili torti is a rare condition characterized by the presence of the hair shaft, which is flattened at irregular intervals and twisted 180° along its long axis. It is a form of hair shaft disorder with increased fragility. The condition is classified into inherited and acquired. Inherited forms may be either isolated or associated with numerous genetic diseases or syndromes (e.g., Menkes disease, Björnstad syndrome, Netherton syndrome, and Bazex-Dupré-Christol syndrome). Moreover, pili torti may be a feature of various ectodermal dysplasias (such as Rapp-Hodgkin syndrome and Ankyloblepharon-ectodermal defects-cleft lip/palate syndrome). Acquired pili torti was described in numerous forms of alopecia (e.g., lichen planopilaris, discoid lupus erythematosus, dissecting cellulitis, folliculitis decalvans, alopecia areata) as well as neoplastic and systemic diseases (such as cutaneous T-cell lymphoma, scalp metastasis of breast cancer, anorexia nervosa, malnutrition, cataracts, and chronic graft-vs.-host disease). The condition may also be induced by several drugs (epidermal growth factor receptor inhibitors, oral retinoids, sodium valproate, and carbamide perhydrate). The diagnosis of pili torti is based on trichoscopic or microscopic examination. As pili torti is a marker of numerous congenital and acquired disorders, in every case, the search for the signs of underlying conditions is recommended.

Fluorescence advanced videodermoscopy: a new method of hairs and scalp evaluation. Comparison with trichoscopy

INTRODUCTION

Non-invasive diagnostic methods in clinical dermatology are widely used to reduce the need for invasive techniques, with great advantages in terms of cost and time. Dermoscopy is the reference test for the in vivo diagnosis of cutaneous lesions, and when it is performed on the scalp region it is named trichoscopy. Fluorescence advanced videodermoscopy (FAV) has been lately proposed as a new non-invasive method for the in vivo skin examination at high magnification, with cell-level resolution. So far, it has shown promising results for the assessment of melanocytic and vascular lesions and for the in vivo diagnosis of parasitosis.

OBJECTIVES

This observational study aims to perform, for the first time, a morphologic study of healthy scalp and scalp elementary lesions using FAV and to compare it with trichoscopy.

METHODS

We enrolled 90 healthy individuals for the evaluation of the scalp using FAV. Then, we recruited 53 patients with alopecia and collected images of the elementary lesions using FAV and trichoscopy.

RESULTS

Three hundred healthy scalp FAV images of different epidermal layers, papillary dermis, follicular ostia and healthy hair shafts were collected. Three hundred and eighty FAV and trichoscopic images of alopecic scalp elementary lesions were collected, showing that FAV provided a more detailed observation than trichoscopy, with higher magnification and cellular resolution.

CONCLUSION

Fluorescence advanced videodermoscopy may represent a new valid technique of support to trichoscopy, adding further information, increasing chances of diagnosis and decreasing the need of invasive procedures.

Ultra high-frequency ultrasound with seventy-MHz transducer in hair disorders: Development of a novel noninvasive diagnostic methodology

BACKGROUND

Ultra high-frequency ultrasound (uHFUS) is a recently developed diagnostic technology. Despite its potential usefulness, no study has assessed its advantage in diagnosis and evaluation of hair disorders in comparison with other diagnostic methods.

OBJECTIVES

To assess the practicability of uHFUS in diagnosing hair disorders and propose a diagnostic methodology.

METHODS

Ultrasonographic images of scalp and forehead from patients with hair disorders (n = 103) and healthy controls (n = 40) were obtained by uHFUS and analyzed by both descriptive and numerical parameters. Furthermore, the data were compared with trichoscopic and histopathological findings.

RESULTS

The pattern of inflammation and fibrosis, hair cycle abnormality, and the findings in subcutis were detected by uHFUS. Significant differences were noted in the numerical parameters associated with the number of hair shafts and follicles, hair diameters and their diversity, and dermal echogenicity in both cicatricial and non-cicatricial hair disorders. Findings in uHFUS were associated with those observed in trichoscopy and scalp biopsy but uHFUS was able to detect pathological findings associated with hair cycle, inflammation, fibrosis, and subcutaneous abnormalities, which are hardly assessable by trichoscopy.

CONCLUSION

The findings of this study highlighted usefulness of uHFUS in diagnosing hair disorders, while overcoming the weaknesses and limitations of other diagnostic tools.

Trichoscopic Findings in Androgenetic Alopecia

Background:

Androgenetic alopecia (AGA) is an androgen-related condition that develops in genetically predisposed individuals. The condition is characterized by the progressive loss of terminal hairs on the scalp in a characteristic distribution. Trichoscopy represents the dermoscopy imaging of the scalp and hair. Structures which may be visualized by trichoscopy include hair shafts, hair follicle openings, perifollicular epidermis and cutaneous microvessels.

Objective:

The aim of this prospective study was to identify the trichoscopic features of androgenetic alopecia.

Methods:

Hundred-four patients with AGA and 80 healthy subjects were enrolled in this study. Data on age, gender, personal and family history, clinical type and duration of disease were collected and analyzed. Control group consisted of 80 generally healthy subjects. Trichoscopic examination was performed using either videodermatoscope or handheld dermatoskope. Trichoscopy results were obtained in frontal, occipital and both temporal areas of the scalp, including number of yellow dots and vellus hairs, number of hairs in one pilosebaceous unit and percentage of follicular ostia with perifollicular hyperpigmentation. The data were statistically evaluated.

Results:

The number of yellow dots, pilosebaceous units with only one hair and with perifollicular hyperpigmentation was significantly increased in androgenetic alopecia (p<0.05). The percentage of thin hairs (<0.03 mm) in AGA was significantly higher than in healthy controls (p<0.05).

Conclusion:

Our study has shown the significances of trichoscopy of patients with AGA. Regular clinical and trichoscopical follow-ups are very important to monitor disease activity and treatment tolerance.