Histologic features of chronic cutaneous lupus erythematosus of the scalp using horizontal sectioning: Emphasis on follicular findings

The role of the scalp biopsy in the evaluation of alopecia

A biopsy should be performed whenever the diagnosis is in doubt. A 4-mm punch biopsy sectioned horizontally at multiple levels is best. In general, noncicatricial alopecia should be sampled where hair is sparsest (most involved area), and cicatricial alopecia should be biopsied in an area of active disease, which is best determined using a dermatoscope and is most often at the margin of a lesion. The goal with cicatricial alopecia is to capture both follicular scars as well as actively inflamed hairs. Information provided by the clinician to the pathologist can be decisive in rendering a definitive diagnosis. The wording of the biopsy report provides a clue to the confidence of the pathologist's diagnosis.

Comparative histopathological analyses of non-scarring alopecia in systemic lupus erythematosus patients in Lagos Nigeria

Background

Systemic lupus erythematosus (SLE) is known to cause non-scarring alopecia. However, histopathological evaluation is uncommon.

Aim

The objective of this study was to document the histopathology of non-scarring alopecia and to compare histopathology of alopecic and normal appearing scalp areas in SLE hair loss patients.

Patients and Methods

A cross-sectional comparative evaluation of scalp biopsies from 23 SLE patients; 12 with hair loss and 11 without was conducted over a 7-month period in 2020. A total of 58 scalp biopsies stained with H and E (23 vertical and 35 cross-sectional) were evaluated. Mucin deposit evaluation was done using Alcian blue (pH 2.5).

Results

There were no significant differences in the sociodemographic data between the patients. The SLE hair loss patients demonstrated mucin deposition (91.7%), reduced size/number of sebaceous glands (58.3%), epidermal atrophy (50.0%), naked arrector pili muscles (50.0%), lymphocytic infiltration (33.3%), pigment incontinence (16.7%), fibrous stellae (16.7%), increased telogen percentage, and increased terminal versus vellus hair ratios. On comparing the histopathology of those who had hair loss to those without hair loss, the only significant difference was in the number and size of sebaceous gland. There were no significant differences between scalp areas with and without hair loss in the SLE hair loss patients.

Conclusion

There are differences in size and number of sebaceous glands on histopathology between SLE patients who have hair loss and those who do not. Also, there are no histopathological differences between alopecic and non-alopecic scalp areas of SLE patient.

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.

Scarring Alopecias: Pathology and an Update on Digital Developments

Primary cicatricial alopecias (PCA) represent a challenging group of disorders that result in irreversible hair loss from the destruction and fibrosis of hair follicles. Scalp skin biopsies are considered essential in investigating these conditions. Unfortunately, the recognised complexity of histopathologic interpretation is compounded by inadequate sampling and inappropriate laboratory processing. By sharing our successes in developing the communication pathway between the clinician, laboratory and histopathologist, we hope to mitigate some of the difficulties that can arise in managing these conditions. We provide insight from clinical and pathology practice into how diagnoses are derived and the key histological features observed across the most common PCAs seen in practice. Additionally, we highlight the opportunities that have emerged with advances in digital pathology and how these technologies may be used to develop clinicopathological relationships, improve working practices, enhance remote learning, reduce inefficiencies, optimise diagnostic yield, and harness the potential of artificial intelligence (AI).

Physical properties of gold nanoparticles affect skin penetration via hair follicles

Drug penetration through the skin is significant for both transdermal and dermal delivery. One mechanism that has attracted attention over the last two decades is the transport pathway of nanoparticles via hair follicle, through the epidermis, directly to the pilosebaceous unit and blood vessels. Studies demonstrate that particle size is an important factor for drug penetration. However, in order to gain more information for the purpose of improving this mode of drug delivery, a thorough understanding of the optimal physical particle properties is needed. In this study, we fabricated fluorescently labeled gold nanoparticles (GNP) with a tight control over the size and shape. The effect of the particles' physical parameters on follicular penetration was evaluated histologically. We used horizontal human skin sections and found that the optimal size for polymeric particles is 0.25 μm. In addition, shape penetration experiments revealed gold nanostars' superiority over spherical particles. Our findings suggest the importance of the particles' physical properties in the design of nanocarriers delivered to the pilosebaceous unit.

Recent Insight on the Management of Lupus Erythematosus Alopecia

Lupus erythematosus (LE) is a chronic autoimmune condition with a wide spectrum of clinical presentations. Alopecias, both non-scarring and scarring, frequently occur in the context of LE and can assume several different patterns. Furthermore, alopecia occurring with LE may be considered LE-specific if LE-specific features are present on histology; otherwise, alopecia is considered non-LE-specific. Non-scarring alopecia is highly specific to systemic LE (SLE), and therefore has been regarded as a criterion for the diagnosis of SLE. Variants of cutaneous LE (CLE), including acute, subacute, and chronic forms, are also capable of causing hair loss, and chronic CLE is an important cause of primary cicatricial alopecia. Other types of hair loss not specific to LE, including telogen effluvium, alopecia areata, and anagen effluvium, may also occur in a patient with lupus. Lupus alopecia may be difficult to treat, particularly in cases that have progressed to scarring. The article summarizes the types of lupus alopecia and recent insight regarding their management. Data regarding the management of lupus alopecia are sparse and limited to case reports, and therefore, many studies including in this review report the efficacy of treatments on CLE as a broader entity. In general, for patients with non-scarring alopecia in SLE, management is aimed at controlling SLE activity with subsequent hair regrowth. Topical medications can be used to expedite recovery. Prompt treatment is crucial in the case of chronic CLE due to potential for scarring and irreversible damage. First-line therapies for CLE include topical corticosteroids and oral antimalarials, with or without oral corticosteroids as bridging therapy. Second and third-line systemic treatments for CLE include methotrexate, retinoids, dapsone, mycophenolate mofetil, and mycophenolate acid. Additional topical and systemic medications as well as physical modalities used for the treatment of lupus alopecia and CLE are discussed herein.

Transverse sectioning in the evaluation of skin biopsy specimens from alopecic dogs

OBJECTIVES

Transverse sectioning of skin biopsy specimens has revolutionised assessment of human alopecia by demonstration of every hair in each specimen, allowing quantitative evaluation of follicular activity. Since only vertical sectioning is performed routinely in veterinary laboratories, we aimed to determine whether transverse sectioning was a valuable technique in assessment of canine alopecia.

METHODS

Paired vertical and transverse sections of biopsy specimens from 31 alopecic dogs were examined independently in triplicate in random order and blinded to previous diagnosis using a standard check-list proforma. Assessments of key features (follicular activity [anagen/telogen], infundibular hyperkeratosis, sebaceous gland abnormalities, pigment clumping, dermal inflammation) by each sectioning method were compared.

RESULTS

In the 31 cases, (atrophic [n = 13], dysplastic [n = 12], inflammatory diseases [n = 6]), follicular inactivity scores (median, [lower-upper quartile]) in transverse sections significantly exceeded those in vertical sections (transverse 4 [3-5], vertical 3 [2-4]). Agreement between the two sectioning planes was moderate for infundibular hyperkeratosis (kappa = 0.5210) and dermal inflammation (0.4351), fair for sebaceous gland abnormalities (0.3966) and pigment clumping (0.2197), but slight for follicular activity (0.1041). Vertical sectioning demonstrated diagnostically important epidermal pathology (n = 2) and dermal thinning (n = 3) whereas transverse sectioning enhanced assessment of hair growth phase (n = 11), follicular structure and architecture (n = 11), and focal luminal or mural folliculitides (n = 3).

CLINICAL SIGNIFICANCE

Transverse sectioning confers significant benefits and complements traditional vertical sectioning in the histological assessment of canine hair follicle diseases, particularly when subtle abnormalities comprise distorted compound follicle architecture, hair cycle arrest or when relatively few adnexal structures are affected.

Value of CD123 Immunohistochemistry and Elastic Staining in Differentiating Discoid Lupus Erythematosus from Lichen Planopilaris

Background:

Differentiating scarring alopecia secondary to lichen planopilaris (LPP) and discoid lupus erythematosus (DLE) has always been a challenge clinically and pathologically. Plasmacytoid dendritic cells (PDCs) have been reported in the cutaneous lupus erythematosus by CD123 immunostaining. This study assesses CD123 marker positivity and patterns of elastic fiber loss in scalp biopsy to differentiate DLE from LLP.

Patients and Methods:

Forty-three cases with clinical and pathological diagnosis of LPP and DLE were selected, and CD123 immunohistochemistry staining and elastic staining were performed on them. The presence of CD123-positive cells, clustering and distribution of cells, and patterns of elastic fibers loss in the dermis were evaluated. To analyze the data, the Chi-square test was used; moreover, the sensitivity and specificity of CD123 were calculated based on a diagnostic test for 2-by-2 tables.

Results:

Infiltration of PDC was seen in 90% of DLE cases. The presence of more than 10% and 20% PDC cells in inflammatory cells had 90% and 85% sensitivity and 34.7% and 91.3% specificity, respectively. PDC clusters more than 20 cells had 100% specificity for DLE. Location and patterns of PDC infiltration were not statistically significant (P = 0.378). The wedge-shaped loss of elastic fibers and the diffuse loss were the dominant patterns in LPP and DLE, respectively (P = 0.006).

Conclusion:

Our results suggested that CD123 along with elastic staining and histological features might be useful to diagnose challenging cases of lymphocytic scarring alopecia with clinical differential diagnosis of LPP and DLE.

Histopathologic and dermoscopic features of 42 cases of folliculitis decalvans: A case series

BACKGROUND

Folliculitis decalvans (FD) is a form of inflamed primary cicatricial alopecia (PCA). FD is classified as a neutrophilic PCA; however, only a few previous studies have described its histopathology, including the assessment of systematically evaluated and quantified follicular changes in horizontally sectioned biopsy specimens with clinical and dermoscopic findings of the early and advanced stages.

OBJECTIVE

We aimed to clarify the histopathologic and dermoscopic features of early and advanced active stage FD.

METHODS

We conducted a case series study of 42 patients with FD by dermoscopy and both horizontally and vertically sectioned biopsy specimens.

RESULTS

The histopathologic findings of the early-stage lesions included loss of sebaceous glands; interfollicular acanthosis; and fibrosis with depressed, fused follicular infundibula showing thickened interfollicular keloid-like areas with tufted hairs on dermoscopy. Active lesions showed a greater number of hair clusters, clefting, and fused infundibula with dense inflammation predominantly in the upper follicles. Neutrophil-predominant infiltrates were observed in fewer than half of the patients, including those with early-stage lesions.

LIMITATIONS

This was a retrospective study.

CONCLUSION

FD has the features of mixed-cell PCA. The features of early-stage FD are thickened interfollicular keloid-like areas with tufted hairs and loss of sebaceous glands.

Non-invasive Approaches for the Diagnosis of Autoimmune/Autoinflammatory Skin Diseases-A Focus on Psoriasis and Lupus erythematosus

The traditional diagnostic gold standard for inflammatory skin lesions of unclear etiology is dermato-histopathology. As this approach requires an invasive skin biopsy, biopsy processing and analysis by specialized histologists, it is a resource intensive approach requiring trained healthcare professionals. In many health care settings access to this diagnostic approach can be difficult and outside emergency cases will usually take several weeks. This scenario leads to delayed or inappropriate treatment given to patients. With dramatically increased sensitivity of a range of analysis systems including mass spectrometry, high sensitivity, multiplex ELISA based systems and PCR approaches we are now able to "measure" samples with unprecedented sensitivity and accuracy. Other important developments include the long-term monitoring of parameters using microneedle approaches and the improvement in imaging systems such as optical coherence tomography. In this review we will focus on recent achievements regarding measurements from non-invasive sampling, in particular from plucked hair and skin tape-strips which seem well suited for the diagnosis of lupus erythematosus and psoriatic inflammation, respectively. While these approaches will not replace clinical observation-they can contribute to improved subgroup diagnosis, stratified therapeutic approaches and have great potential for providing molecular and mechanistic insight in to inflammatory skin diseases.

Alopecia as a systemic disease

Alopecia is a skin condition of great social and psychologic impact. Primary alopecia originates from the hair follicles and usually does not have systemic manifestations; however, secondary alopecia can affect the hair follicles in the setting of systemic diseases, medications, and external trauma. Connective tissue diseases, granulomatous diseases, bullous diseases, infections, and tumors are some of the systemic diseases that will be covered in this review. Trichoscopy is a useful noninvasive tool that can help with the diagnosis in the office and can guide the selection of the optimal site for the scalp biopsy. Histopathology is the ultimate tool for the diagnosis in most cases of secondary alopecia and can be performed on vertical and horizontal sections. In most cases, treating the underlying condition is the single most important strategy, but topical treatments for the alopecia are also applied.

Plucked hair follicles from patients with chronic discoid lupus erythematosus show a disease-specific molecular signature

OBJECTIVE

When faced with clinical symptoms of scarring alopecia-the standard diagnostic pathway involves a scalp biopsy which is an invasive and expensive procedure. This project aimed to assess if plucked hair follicles (HFs) containing living epithelial cells can offer a non-invasive approach to diagnosing inflammatory scalp lesions.

METHODS

Lesional and non-lesional HFs were extracted from the scalp of patients with chronic discoid lupus erythematosus (CDLE), psoriasis and healthy controls. RNA was isolated from plucked anagen HFs and microarray, as well as quantitative real-time PCR was performed.

RESULTS

Here, we report that gene expression analysis of only a small number of HF plucked from lesional areas of the scalp is sufficient to differentiate CDLE from psoriasis lesions or healthy HF. The expression profile from CDLE HFs coincides with published profiles of CDLE from skin biopsy. Genes that were highly expressed in lesional CDLE corresponded to well-known histopathological diagnostic features of CDLE and included those related to apoptotic cell death, the interferon signature, complement components and CD8+ T-cell immune responses.

CONCLUSIONS

We therefore propose that information obtained from this non-invasive approach are sufficient to diagnose scalp lupus erythematosus. Once validated in routine clinical settings and compared with other scarring alopecias, this rapid and non-invasive approach will have great potential for paving the way for future diagnosis of inflammatory scalp lesions.

Alopecias in lupus erythematosus

Several patterns of hair loss can occur in lupus erythematosus (LE). Alopecias which show histological characteristics of LE are LE-specific, and include discoid LE (DLE), diffuse or patchy hair loss in acute LE, subacute cutaneous LE, and rarely tumid LE. Lupus hair in SLE is a poorly characterised entity and may be a form of telogen effluvium. Alopecia areata can coexist with LE and may mimic DLE. Non-lupus alopecias such as telogen effluvium and anagen effluvium have a myriad of causes which include disease flares, drugs and stress in the setting of LE. The latest validated Systemic Lupus International Collaborating Clinics classification criteria for SLE includes non-scarring alopecia as a criterion; therefore, recognising the aetiology of hair loss in the setting of LE is crucial in classifying a patient to have systemic disease.