Dermoscopic findings and comparison of usefulness of longitudinal versus transversal sections in the histological diagnosis of alopecia X.

BACKGROUND: A combination of dermoscopic and histological findings may provide useful information for the diagnosis of hair follicle diseases. However, there are no studies on dermoscopic-histopathological correlations in dogs affected by alopecia X, and comparison of longitudinal versus transversal sectioning of skin biopsy specimens in the assessment of this hair loss disorder has not been thoroughly investigated. HYPOTHESIS/OBJECTIVES: The aim of this study was to correlate dermoscopic and histological features using both longitudinal and transversal sectioning of skin biopsy samples to gain additional information for the diagnosis of alopecia X. ANIMALS: Nineteen Pomeranian dogs affected by alopecia X and five healthy Pomeranians as controls. MATERIALS AND METHODS: Dermoscopic-histological correlation was performed within the diseased group, whereas histological comparisons against controls. The demographic and clinical characteristics also were related to the histological findings. RESULTS: The dermoscopic findings revealed scattered, thinned, short hairs mixed with amorphous keratoseborrhoeic-like material (follicular plugging), perifollicular and intrafollicular scaling, and hyperpigmentation varying from pinpoint black spots to a diffuse texture. Dermoscopic findings correlated with histological findings for selected qualitative and quantitative findings. The usefulness of transversal sections was demonstrated in accurately determining the hair follicular density and counts, growth arrest phases and in identifying mineralisation of hair follicle basement membrane when compared to the longitudinal. Conversely, no correlations between histological findings and demographic and clinical characteristics were detected. CONCLUSIONS AND CLINICAL RELEVANCE: These data provide evidence of the usefulness of dermoscopic evaluation as an accessory diagnostic tool and of transversal sections of skin biopsies as complementary to the diagnosis of alopecia X.

Diagnosis and differential diagnosis of tertiary androgenetic alopecia with severe alopecia areata based on high-resolution MRI.

BACKGROUND AND AIM: No previous study investigated the anatomical changes of the scalp and hair follicles between tertiary androgenetic alopecia and severe alopecia areata using high-resolution magnetic resonance imaging (HR-MRI). This study aimed to explore the value of HR-MRI in assessing alopecia. MATERIALS AND METHODS: Forty-eight people were included in this study. The imaging indicators of the vertex and occipital scalp were recorded and compared. The logistic regression model was developed for the indicators that differed between tertiary androgenetic alopecia and severe alopecia areata. The receiver-operating characteristic (ROC) curve was used to assess the diagnostic efficacy of the model for tertiary androgenetic alopecia and severe alopecia areata. RESULTS: At the vertex, the thickness of the subcutaneous tissue layer, follicle depth, relative follicle depth, total number of follicles within a 2-cm distance, and number of strands reaching the middle and upper third of the subcutaneous fat layer within a 2-cm distance were statistically different between patients with tertiary androgenetic alopecia, those with severe alopecia areata, and healthy volunteers (p < 0.05). The logistic regression model suggested that the subcutaneous tissue layer thickness was important in discriminating tertiary androgenetic alopecia from severe alopecia areata. The ROC curve showed that the area under the curve, sensitivity, specificity, and best cutoff values of the subcutaneous tissue layer were 0.886, 94.4%, 70%, and 4.31 mm, respectively. CONCLUSIONS: HR-MRI can observe the changes in anatomical structures of the scalp and hair follicles in patients with alopecia. HR-MRI can be applied to the differential diagnosis of tertiary androgenetic alopecia and severe alopecia areata.

Tricoscopia en la alopecia areata / Trichoscopy in Alopecia Areata

La alopecia areata es una enfermedad autoinmune, que afecta al folículo piloso. Se presenta en forma de placas alopécicas e incluso pérdida de pelo corporal. El diagnóstico es clínico. Sin embargo, la tricoscopia, una técnica valiosa no invasiva, simple y rápida, mejora el diagnóstico, la monitorización del tratamiento y reduce la necesidad de procedimientos invasivos. Realizaremos una descripción de la utilidad de la tricoscopia en la alopecia areata. Los hallazgos tricoscópicos más frecuentes de la alopecia areata son los puntos amarillos, los puntos negros, pelos en signos de exclamación, pelos vellosos cortos, pelos acodados. Sin embargo, existen otros hallazgos menos frecuentes, pero útiles para realizar el diagnóstico. La buena respuesta al tratamiento implica la desaparición de los puntos negros, pelos rotos y pelos con signo de exclamación, pero la presencia de los puntos amarillos indica enfermedad crónica y mala respuesta (AU)

Alopecia areata is an autoimmune disease that affects the hair follicle and can present as bald patches on the scalp and hair loss in other parts of the body. Diagnosis is clinical but can be aided by trichoscopy, a simple, rapid technique that reduces the need for invasive procedures and can also help with monitoring treatment response. We review the usefulness of trichoscopy in alopecia areata. The most common trichoscopic findings are yellow dots, black dots, exclamation mark hairs, short vellus hairs, and coudability hairs. Other, less common, findings can also help establish a diagnosis. Good response to treatment is indicated by the disappearance of black dots, broken hairs, and exclamation mark hairs. The observation of yellow dots, by contrast, indicates chronic disease and poor response to treatment (AU)

[Translated article] Trichoscopy in Alopecia Areata / Tricoscopia en la alopecia areata

Alopecia areata is an autoimmune disease that affects the hair follicle and can present as bald patches on the scalp and hair loss in other parts of the body. Diagnosis is clinical but can be aided by trichoscopy, a simple, rapid technique that reduces the need for invasive procedures and can also help with monitoring treatment response. We review the usefulness of trichoscopy in alopecia areata. The most common trichoscopic findings are yellow dots, black dots, exclamation mark hairs, short vellus hairs, and coudability hairs. Other, less common, findings can also help establish a diagnosis. Good response to treatment is indicated by the disappearance of black dots, broken hairs, and exclamation mark hairs. The observation of yellow dots, by contrast, indicates chronic disease and poor response to treatment (AU)

La alopecia areata es una enfermedad autoinmune, que afecta al folículo piloso. Se presenta en forma de placas alopécicas e incluso pérdida de pelo corporal. El diagnóstico es clínico. Sin embargo, la tricoscopia, una técnica valiosa no invasiva, simple y rápida, mejora el diagnóstico, la monitorización del tratamiento y reduce la necesidad de procedimientos invasivos. Realizaremos una descripción de la utilidad de la tricoscopia en la alopecia areata. Los hallazgos tricoscópicos más frecuentes de la alopecia areata son los puntos amarillos, los puntos negros, pelos en signos de exclamación, pelos vellosos cortos, pelos acodados. Sin embargo, existen otros hallazgos menos frecuentes, pero útiles para realizar el diagnóstico. La buena respuesta al tratamiento implica la desaparición de los puntos negros, pelos rotos y pelos con signo de exclamación, pero la presencia de los puntos amarillos indica enfermedad crónica y mala respuesta (AU)

Quantitative characterization of 3D structure of vellus hair arrector pili muscles by micro CT.

BACKGROUND: Vellus hair is the fine, wispy hair found over most of the body surface, and the arrector pili muscles (hair muscle) serve to raise these hairs. Hair muscles are also critical for skin regeneration, contributing to the maintenance of stem cells in epidermis and hair follicles. However, little is known about their fundamental properties, especially their structure, because of the limitations of conventional two-dimensional histological analysis. OBJECTIVES: We aimed to quantitatively characterize the structure of vellus hair muscles by establishing a method to visualize the 3D structure of hair muscle. METHODS: We observed young female abdominal skin specimens by means of X-ray micro CT and identified hair muscles in each cross-sectional CT image. We then digitally reconstructed the 3D structure of the hair muscles on computer (digital-3D skin), and numerically evaluated their structural parameters. RESULTS: Vellus hair muscles were clearly distinguished from the surrounding dermal layer in X-ray micro CT images and were digitally reconstructed in 3D from those images for quantification of the structural parameters. The mean value of number of divisions of vellus hair muscles was 1.6, mean depth was 943.6 µm from the skin surface, mean angle to the skin surface was 28.8 degrees, and mean length was 1657.9 µm. These values showed relatively little variation among subjects. The mean muscle volume was approximately 20 million µm3 but showed greater variability than the other parameters. CONCLUSION: Digital-3D skin technology is a powerful approach to understand the tiny but complex 3D structure of vellus hair muscles. The fundamental nature of vellus hair muscles was characterized in terms of their 3D structural parameters, including number of divisions, angle to the skin surface, depth, and volume.

Scanning electron microscopy of murine skin ultrathin sections and cultured keratinocytes.

Generating high-quality electron microscopy images of the skin and keratinocytes can be challenging. Here we describe a simple protocol for scanning electron microscopy (SEM) of murine skin. The protocol enables characterization of the ultrastructure of the epidermis, dermis, hair follicles, basement membrane, and cell-cell junctions. We detail the specific steps for sample preparation and highlight the critical need for proper orientation of the sample for ultrathin sectioning. We also describe the isolation and preparation of primary keratinocyte monolayers for SEM. For complete details on the use and execution of this protocol, please refer to Biswas et al. (2021).

Real-Time Confocal Imaging for Hidradenitis Suppurativa: Description of Morphological Aspects and Focus on the Role of Follicular Ostia.

BACKGROUND: Hidradenitis suppurativa (HS) is a chronic, recurrent, inflammatory skin disease involving the follicular unit. Growing evidence suggests a crucial role of hyperkeratosis, infundibular plugging and perifolliculitis in its pathogenesis. OBJECTIVES: To characterize the microscopic morphology of open comedos using in vivo reflectance confocal microscopy (RCM) and define alterations occurring in HS normal-appearing perilesional skin compared to healthy skin of a control group, discussing therefore microscopic differences. MATERIALS AND METHODS: Twenty patients (11 males, 9 females; aged 19-51 years) affected by HS were recruited. RCM was performed on open comedos of axillary/inguinal regions and on normal-appearing skin areas distant at least 1.5 cm from HS lesions. Ten healthy individuals (6 males, 4 females) were included as control group. RESULTS: RCM aspects of 78 open comedos were explored, observing circular/ovoidal structures disclosing a hyperrefractive amorphous material (72/78, 92.3%) within the infundibular cavity surrounded with a bright (51/78, 65.4%) and regular (52/78, 66.2%) border. Follicular ostia of HS perilesional skin (n = 541) compared to follicular ostia of a control group (n = 321) were characterized by a larger infundibular diameter (183.4 vs. 85.8 µm) and diverged in terms of material collected inside infundibula (44.5 vs. 21%) and keratinization of the border (47.6 vs. 25.5%). CONCLUSION: In vivo characterization of open comedos and the recognition of microscopic subclinical alterations of HS normal-appearing skin, compared to healthy skin, could add further insights into the definition of biological events leading to HS manifestations, including the dysregulated process of keratinization.

Dermal Adipose Tissue Secretes HGF to Promote Human Hair Growth and Pigmentation.

Hair follicles (HFs) are immersed within dermal white adipose tissue (dWAT), yet human adipocyte‒HF communication remains unexplored. Therefore, we investigated how perifollicular adipocytes affect the physiology of human anagen scalp HFs. Quantitative immunohistomorphometry, X-ray microcomputed tomography, and transmission electron microscopy showed that the number and size of perifollicular adipocytes declined during anagen‒catagen transition, whereas fluorescence-lifetime imaging revealed increased lipid oxidation in adipocytes surrounding the bulge and/or sub-bulge region. Ex vivo, dWAT tendentially promoted hair shaft production, and significantly stimulated hair matrix keratinocyte proliferation and HF pigmentation. Both dWAT pericytes and PREF1/DLK1+ adipocyte progenitors secreted HGF during human HF‒dWAT co-culture, for which the c-Met receptor was expressed in the hair matrix and dermal papilla. These effects were reproduced using recombinant HGF and abrogated by an HGF-neutralizing antibody. Laser-capture microdissection‒based microarray analysis of the hair matrix showed that dWAT-derived HGF upregulated keratin (K) genes (K27, K73, K75, K84, K86) and TCHH. Mechanistically, HGF stimulated Wnt/ß-catenin activity in the human hair matrix (increased AXIN2, LEF1) by upregulating WNT6 and WNT10B, and inhibiting SFRP1 in the dermal papilla. Our study demonstrates that dWAT regulates human hair growth and pigmentation through HGF secretion, and thus identifies dWAT and HGF as important novel molecular and cellular targets for therapeutic intervention in human hair growth and pigmentation disorders.

Comparison between single- versus double-spin prepared platelet-rich plasma injection in treatment of female pattern hair loss: clinical effect and relation to vascular endothelial growth factor.

Platelet-rich plasma (PRP) provides a treatment option for female pattern hair loss (FPHL). However, the most suitable preparation method is not yet clear. The primary aim is to compare between the efficacy of single- versus double-spin PRP preparation injection in the treatment of FPHL, while the secondary aim is to assess the relationship between vascular endothelial growth factor (VEGF) concentrations in different prepared PRP preparations (pre- and post-activation) and the obtained treatment results. 15 female patients with FPHL were subjected to intradermal injection of double-spin prepared PRP into the right (Rt) half of the scalp and single-spin prepared PRP into the left (Lt) half of the scalp, three sessions, 3 weeks apart. Evaluation of treatment response was done through comparing patients' photographs, patients' satisfaction and trichoscopic assessment (measurement of terminal hair density) before and after treatment. In addition, VEGF concentration was measured in different PRP samples before and after activation with calcium gluconate. Results showed clinical improvement in both sides of scalp 6 weeks after last PRP session. Meanwhile, Rt median terminal hair density measured by trichoscan following treatment was significantly higher compared to Lt median terminal hair density. Furthermore, VEGF concentration did not differ significantly in single- versus double-spin prepared PRP, or upon calcium activation. PRP is effective in treatment of FPHL. Double-spin method could yield better results than single-spin method. Adding calcium gluconate prior to PRP injection is of no value.

The Alopecia Areata Consensus of Experts (ACE) study part II: Results of an international expert opinion on diagnosis and laboratory evaluation for alopecia areata.

BACKGROUND: We previously reported the Alopecia Areata Consensus of Experts study, which presented results of an international expert opinion on treatments for alopecia areata. OBJECTIVE: To report the results of the Alopecia Areata Consensus of Experts international expert opinion on diagnosis and laboratory evaluation for alopecia areata. METHODS: Fifty hair experts from 5 continents were invited to participate in a 3-round Delphi process. Consensus threshold was set at greater than or equal to 66%. RESULTS: Of 148 questions, expert consensus was achieved in 82 (55%). Round 1 consensus was achieved in 10 of 148 questions (7%). Round 2 achieved consensus in 47 of 77 questions (61%). The final face-to-face achieved consensus in 25 of 32 questions (78%). Consensus was greatest for laboratory evaluation (12 of 14 questions [86%]), followed by diagnosis (11 of 14 questions [79%]) of alopecia areata. Overall, etiopathogenesis achieved the least category consensus (31 of 68 questions [46%]). LIMITATIONS: The study had low representation from Africa, South America, and Asia. CONCLUSION: There is expert consensus on aspects of epidemiology, etiopathogenesis, clinical features, diagnosis, laboratory evaluation, and prognostic indicators of alopecia areata. The study also highlights areas where future clinical research could be directed to address unresolved hypotheses in alopecia areata patient care.

Combining Deep Learning With Optical Coherence Tomography Imaging to Determine Scalp Hair and Follicle Counts.

BACKGROUND AND OBJECTIVES: One of the challenges in developing effective hair loss therapies is the lack of reliable methods to monitor treatment response or alopecia progression. In this study, we propose the use of optical coherence tomography (OCT) and automated deep learning to non-invasively evaluate hair and follicle counts that may be used to monitor the success of hair growth therapy more accurately and efficiently. STUDY DESIGN/MATERIALS AND METHODS: We collected 70 OCT scans from 14 patients with alopecia and trained a convolutional neural network (CNN) to automatically count all follicles present in the scans. The model is based on a dual approach of both detecting hair follicles and estimating the local hair density in order to give accurate counts even for cases where two or more adjacent hairs are in close proximity to each other. RESULTS: We evaluate our system on 70 OCT manually labeled scans taken at different scalp locations from 14 patients, with 20 of those redundantly labeled by two human expert OCT operators. When comparing the individual human predictions and considering the exact locations of hair and follicle predictions, we find that the two human raters disagree with each other on approximately 22% of hairs and follicles. Overall, the deep learning (DL) system predicts the number of follicles with an error rate of 11.8% and the number of hairs with an error rate of 18.7% on average on the 70 scans. The OCT system can capture one scalp location in three seconds, and the DL model can make all predictions in less than a second after processing the scan, which takes half a minute using an unoptimized implementation. CONCLUSION: This approach is well-positioned to become the standard for non-invasive evaluation of hair growth treatment progress in patients, saving significant amounts of time and effort compared with manual evaluation. Lasers Surg. Med. © 2020 Wiley Periodicals, Inc.

MR Imaging of Hair and Scalp for the Evaluation of Androgenetic Alopecia.

PURPOSE: Although androgenetic alopecia (AGA) is a common cause of hair loss, little is known regarding the magnetic resonance imaging (MRI) of the AGA or scalp. This study aimed to analyze whether MRI for hair and scalp (MRH) can evaluate anatomical changes in the scalp caused by AGA. METHODS: Twenty-seven volunteers were graded for the severity of AGA using the Hamilton-Norwood Scale (HNS), commonly used classification system. All subjects underwent MRH; two radiologists independently analyzed the images. As a quantitative measurement, the number of hair follicles was analyzed and compared with the HNS. As a qualitative analysis, each MRH scan was visually graded in terms of the severity of alopecia, using a 4-point MR severity score. The scores were compared with the HNS. RESULTS: The volunteers were divided into two groups of 12 and 15 males without and with AGA at their vertex, respectively. Inter-observer agreements for the hair count and the MR severity score were excellent. The mean hair count on MRI in the normal group was significantly higher than that in the AGA group (P < 10-4). The MR severity score in the AGA group was significantly more severe than that in the control group (P < 10-4). In terms of the presence or absence of thinning hair, the MR severity score was consistent with the HNS determined by a plastic surgeon in 96% of cases. MR severity scores of clinically moderate AGA cases were significantly lower than those of severe cases (P = 0.022). CONCLUSION: MRH could depict scalp anatomy showing a clear difference between AGA and normal scalps, in both hair count and subjective visual assessment. The MR severity score was in good agreement with the clinical stages by HNS. The results support the potential of MRH as a promising imaging technique for analyzing healthy and pathological scalps.

Quantitative analysis of the anatomical changes in the scalp and hair follicles in androgenetic alopecia using magnetic resonance imaging.

BACKGROUND: Although the structural changes of the scalp in androgenetic alopecia (AGA) have been reported, these changes have been poorly understood. It is expected that modern MRI would visualize the scalp anatomy in vivo. This study aimed to explore whether AGA causes (a) changes in the thickness of the scalp, (b) anatomical changes in the hair follicles, and (c) changes in the signal intensity of MRI. MATERIALS AND METHODS: Twenty-seven volunteers underwent MRI for hair and scalp (MRH) and were categorized into two according to the Hamilton-Norwood Scale: the "AGA group" and the "normal group." Two radiologists analyzed the thickness and signal intensity of the scalp, and the depth of hair follicles. These measurements were compared between the two groups. RESULTS: The thickness of the hypodermis and the entire scalp was significantly thinner in the AGA group than in the control group. The AGA group had significantly shallower depth of hair follicles and relative depth of the hair follicles to that of the entire scalp than the normal group. The hypodermis showed higher signal intensity in the AGA group than the normal group. CONCLUSION: MRH allowed noninvasive visualization of the scalp anatomy and demonstrated the thinner nature of the entire scalp and hypodermis, along with the shallower depth of the hair follicles in the AGA group in comparison to the normal group. Additionally, MRH demonstrated the increased MR signal intensity in the scalp associated with AGA. MRH may be a promising new method for quantitative and objective analyses of AGA.

Trichoscopy of Alopecia Areata: Hair Loss Feature Extraction and Computation Using Grid Line Selection and Eigenvalue.

Recently, the hair loss population, alopecia areata patients, is increasing due to various unconfirmed reasons such as environmental pollution and irregular eating habits. In this paper, we introduce an algorithm for preventing hair loss and scalp self-diagnosis by extracting HLF (hair loss feature) based on the scalp image using a microscope that can be mounted on a smart device. We extract the HLF by combining a scalp image taken from the microscope using grid line selection and eigenvalue. First, we preprocess the photographed scalp images using image processing to adjust the contrast of microscopy input and minimize the light reflection. Second, HLF is extracted through each distinct algorithm to determine the progress degree of hair loss based on the preprocessed scalp image. We define HLF as the number of hair, hair follicles, and thickness of hair that integrate broken hairs, short vellus hairs, and tapering hairs.

Eosinophilic folliculitis due to wearing protective gear in citizens volunteering for sanitation services during the COVID-19 pandemic - an original epidemiological, clinical, dermoscopic, and laboratory-based study.

BACKGROUND: An association between wearing protective gear and eosinophilic folliculitis has not been reported. We aimed to investigate such during the COVID-19 pandemic. METHODS: In three outpatient clinics, we hand-reviewed records of all patients having consulted us during a Study Period (90 days) in the early phase of the pandemic. Our inclusion criteria for Study Subjects were: (i) clear clinical diagnosis, (ii) dermoscopic confirmation, (iii) differential diagnoses excluded, (iv) eosinophilia, (v) protective gear worn during sanitation services, (vi) temporal correlation, (vii) distributional correlation, (viii) physician-assessed association, and (ix) patient-assessed association. Control Periods in the same season were elected. RESULTS: Twenty-five study subjects fulfilled all inclusion criteria. The incidence was significantly higher than in the control periods (IR: 3.57, 95% CI: 1.79-7.43). Male predominance was significant (P < 0.001). Such for patients in the control periods were insignificant. Study subjects were 21.2 (95% CI: 11.0-31.4) years younger than patients in the control periods. For the study subjects, the distribution of erythematous or skin-colored folliculocentric dome-shaped papules and pustules were all compatible with body parts covered by the gear. Lesional biopsy performed on two patients revealed eosinophilic dermal infiltrates within and around the pilosebaceous units. Polarized dermoscopy revealed folliculitis with peri-/interfollicular vascular proliferation. Lesion onsets were 6.4 (SD: 2.1) days after wearing gear. Remissions were 16.7 (SD: 7.5) days after ceasing to wear gear and treatments. CONCLUSIONS: Wearing protective gear in volunteered sanitizing works could be associated with eosinophilic folliculitis. Owing to the significant temporal and distributional correlations, the association might be causal.