Disruption of the endopeptidase ADAM10-Notch signaling axis leads to skin dysbiosis and innate lymphoid cell-mediated hair follicle destruction.

Hair follicles (HFs) function as hubs for stem cells, immune cells, and commensal microbes, which must be tightly regulated during homeostasis and transient inflammation. Here we found that transmembrane endopeptidase ADAM10 expression in upper HFs was crucial for regulating the skin microbiota and protecting HFs and their stem cell niche from inflammatory destruction. Ablation of the ADAM10-Notch signaling axis impaired the innate epithelial barrier and enabled Corynebacterium species to predominate the microbiome. Dysbiosis triggered group 2 innate lymphoid cell-mediated inflammation in an interleukin-7 (IL-7) receptor-, S1P receptor 1-, and CCR6-dependent manner, leading to pyroptotic cell death of HFs and irreversible alopecia. Double-stranded RNA-induced ablation models indicated that the ADAM10-Notch signaling axis bolsters epithelial innate immunity by promoting ß-defensin-6 expression downstream of type I interferon responses. Thus, ADAM10-Notch signaling axis-mediated regulation of host-microbial symbiosis crucially protects HFs from inflammatory destruction, which has implications for strategies to sustain tissue integrity during chronic inflammation.

Obesity accelerates hair thinning by stem cell-centric converging mechanisms.

Obesity is a worldwide epidemic that predisposes individuals to many age-associated diseases, but its exact effects on organ dysfunction are largely unknown1. Hair follicles-mini-epithelial organs that grow hair-are miniaturized by ageing to cause hair loss through the depletion of hair follicle stem cells (HFSCs)2. Here we report that obesity-induced stress, such as that induced by a high-fat diet (HFD), targets HFSCs to accelerate hair thinning. Chronological gene expression analysis revealed that HFD feeding for four consecutive days in young mice directed activated HFSCs towards epidermal keratinization by generating excess reactive oxygen species, but did not reduce the pool of HFSCs. Integrative analysis using stem cell fate tracing, epigenetics and reverse genetics showed that further feeding with an HFD subsequently induced lipid droplets and NF-κB activation within HFSCs via autocrine and/or paracrine IL-1R signalling. These integrated factors converge on the marked inhibition of Sonic hedgehog (SHH) signal transduction in HFSCs, thereby further depleting lipid-laden HFSCs through their aberrant differentiation and inducing hair follicle miniaturization and eventual hair loss. Conversely, transgenic or pharmacological activation of SHH rescued HFD-induced hair loss. These data collectively demonstrate that stem cell inflammatory signals induced by obesity robustly represses organ regeneration signals to accelerate the miniaturization of mini-organs, and suggests the importance of daily prevention of organ dysfunction.

Polydopamine Synergizes with Quercetin Nanosystem to Reshape the Perifollicular Microenvironment for Accelerating Hair Regrowth in Androgenetic Alopecia.

Accumulated reactive oxygen species (ROS) and their resultant vascular dysfunction in androgenic alopecia (AGA) hinder hair follicle survival and cause permanent hair loss. However, safe and effective strategies to rescue hair follicle viability to enhance AGA therapeutic efficiency remain challenging. Herein, we fabricated a quercetin-encapsulated (Que) and polydopamine-integrated (PDA@QLipo) nanosystem that can reshape the perifollicular microenvironment to initial hair follicle regeneration for AGA treatment. Both the ROS scavenging and angiogenesis promotion abilities of PDA@QLipo were demonstrated. In vivo assays revealed that PDA@QLipo administrated with roller-microneedles successfully rejuvenated the "poor" perifollicular microenvironment, thereby promoting cell proliferation, accelerating hair follicle renewal, and facilitating hair follicle recovery. Moreover, PDA@QLipo achieved a higher hair regeneration coverage of 92.5% in the AGA mouse model than minoxidil (87.8%), even when dosed less frequently. The nanosystem creates a regenerative microenvironment by scavenging ROS and augmenting neovascularity for hair regrowth, presenting a promising approach for AGA clinical treatment.

Effect of N-acetylcysteine on hair follicle changes in mouse model of cyclophosphamide-induced alopecia: histological and biochemical study.

Chemotherapy-induced alopecia (CIA) represents one of the most severe side effects of chemotherapy, which forces some patients to reject cancer treatment. The exact pathophysiological mechanisms of CIA are not clearly understood, which makes it difficult to discover efficient preventive or therapeutic procedures for this adverse effect. N-acetylcysteine (NAC) has a strong antioxidant activity as it stimulates glutathione synthesis and acts as an oxygen radical scavenger. The current study tried to investigate the efficacy of NAC in preserving biochemical parameters and hair follicle structure against cyclophosphamide (CYP) administration. In total, 40 adult female C57BL/6 mice were induced to enter anagen by depilation (day 0) and divided into four groups: group I (control), group II (CYP) received a single dose of CYP [150 mg/kg body weight (B.W.)/intraperitoneal injection (IP)] at day 9, group III (CYP & NAC) received a single dose of CYP at day 9 as well as NAC (500 mg/kg B.W./day/IP) from day 6-16, and group IV (NAC) received NAC from day 6-16. CYP administration in group II induced an increase in malondialdehyde (MDA), decrease in superoxide dismutase (SOD), histological hair follicle dystrophy, disruption of follicular melanogenesis, overexpression of p53, and loss of ki67 immunoreactivity. NAC coadministration in group III reversed CYP-induced alterations in the biochemical parameters and preserved hair follicle structure, typical follicular melanin distribution as well as normal pattern of p53 and ki67 expression. These findings indicated that NAC could be used as an efficient and safe therapeutic option for hair loss induced by chemotherapy.

Lessons from a scoping review: Clinical presentations of central centrifugal cicatricial alopecia.

BACKGROUND: Central centrifugal cicatricial alopecia (CCCA) nomenclature describes a typical clinical presentation of cicatricial hair loss that begins on the vertex scalp with progressive, symmetric, and centrifugal evolution. However, atypical presentations have been noted clinically by the authors and reported in the literature. OBJECTIVE: We sought to characterize the distribution of hair loss in published cases of adult patients with CCCA. METHODS: A 3-step search process was used to evaluate research articles in Cumulative Index to Nursing & Allied Health, EMBASE, Google Scholar, MEDLINE, Scopus, and Web of Science databases. Studies with scalp photography or description of hair loss distribution were included. Three researchers evaluated eligible studies for clinical subtypes. Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Review was used to report results. RESULTS: Ninety-nine studies consisting of 281 cases of CCCA were included. Hair loss distributions included variants of the classic presentation along with distinct subtypes such as patchy, occipital, parietal, frontal, temporal, and trichorrhexis. LIMITATIONS: Studies had significant homogeneity, as the classic distribution of CCCA was commonly reported. Additionally, clinically diagnosed cases may have concurrent diagnoses, and numerous studies did not report trichoscopy findings. CONCLUSION: CCCA terminology may not always be reflective of clinical presentation. Understanding atypical presentations is essential to inform appropriate and targeted treatment.

Sebaceous gland atrophy due to seborrheic dermatitis in a patient with alopecia: A potential pitfall.

Seborrheic dermatitis is an inflammatory condition that usually presents with erythema, scaly greasy papules, and plaques affecting sebaceous gland-rich areas and predominantly involving the face and scalp. The diagnosis of seborrheic dermatitis can often be rendered based on the clinical presentation. However, in certain cases, a biopsy can be useful to distinguish it from clinical mimics such as psoriasis, discoid lupus, and rosacea. Prominent sebaceous gland atrophy without scarring has been well-described as an important and relatively specific clue for psoriatic or drug-induced alopecia. However, sebaceous gland atrophy is not specific to psoriasis and has been demonstrated in seborrheic dermatitis, facial discoid dermatitis, and potentially may occur in other inflammatory dermatoses of the scalp. We report a 23-year-old female patient presenting with non-scarring hair loss and histopathological findings demonstrating mild androgenetic alopecia and changes of seborrheic dermatitis with dramatic sebaceous gland atrophy. The patient had no history or evidence of psoriasis clinically. Our case suggests that in patients with seborrheic dermatitis, sebaceous gland atrophy may complicate the evaluation of alopecia biopsies and should be recognized as a pitfall. Seborrheic dermatitis should be included in the differential diagnosis of alopecia biopsies showing prominent sebaceous gland atrophy.

Clinical Characterization and Treatment Response of Folliculitis Decalvans Lichen Planopilaris Phenotypic Spectrum: A Unicentre Retrospective Series of 31 Patients.

Folliculitis decalvans and lichen planopilaris phenotypic spectrum has been described as a form of cicatricial alopecia. The aim of this study is to describe the clinical and trichoscopic features and therapeutic management of this condition in a series of patients. A retrospective observational unicentre study was designed including patients with folliculitis decalvans and lichen planopilaris phenotypic spectrum confirmed with biopsy. A total of 31 patients (20 females) were included. The most common presentation was an isolated plaque of alopecia (61.3%) in the vertex. Trichoscopy revealed hair tufting with perifollicular white scaling in all cases. The duration of the condition was the only factor associated with large plaques (grade III) of alopecia (p = 0.026). The mean time to transition from the classic presentation of folliculitis decalvans to folliculitis decalvans and lichen planopilaris phenotypic spectrum was 5.2 years. The most frequently used treatments were topical steroids (80.6%), intralesional steroids (64.5%) and topical antibiotics (32.3%). Nine clinical relapses were detected after a mean time of 18 months (range 12-23 months). Folliculitis decalvans and lichen planopilaris phenotypic spectrum is an infrequent, but probably underdiagnosed, cicatricial alopecia. Treatment with anti-inflammatory drugs used for lichen planopilaris may be an adequate approach.

Transcriptome analysis of frontal fibrosis alopecia revealed involvement of immune cells and ferroptosis.

BACKGROUND: Frontal fibrosis alopecia (FFA) is a primary cicatricial alopecia and has received increasing attention in recent years. However, the pathogenesis of FFA has not been fully elucidated. METHODS AND RESULTS: Herein, we collected the transcriptome data of scalp lesions of seven patients with FFA and seven healthy controls. The differential expression analysis and weighted gene co-expression network analysis were conducted and we identified 458 differentially expressed genes (DEGs) in two key modules. Later, we performed functional enrichment analysis and functional modules identification, revealing the participation of immune response and fatty acid metabolism. Based on the results, we processed further studies. On the one hand, we analyzed the infiltrating immune cells of FFA through CIBERSORT algorithm, indicating the activation of M1 macrophage and CD8+ T cell. On the other hand, considering lipid metabolism of FFA and oxidative stress of hair follicle cells in alopecia, we explored the potential ferroptosis of FFA. By intersection of DEGs and ferroptosis-related genes from FerrDb database, 19 genes were identified and their expression was validated in an external dataset containing 36 FFA cases and 12 controls. Then, we used LASSO algorithms to construct a four-gene diagnostic model, which achieved an AUC of 0.924 in validation dataset. Additionally, the immune cells were found to be related to ferroptosis in FFA. CONCLUSION: Taken together, this study contributed to reveal the molecular mechanisms of FFA and is expected to inspire future research on treatment.

Sonographic comparison of subcutaneous fat layer thickness in the scalp area in patients with androgenetic alopecia compared to healthy individuals: Cross-sectional.

INTRODUCTION: Androgenetic alopecia (AGA) is one of the most common alopecia among men and women worldwide. It is a nonscarring alopecia that has a characterized pattern. In female pattern AGA, the hairline is stable but general thinning occurs most notably in the frontal region. In male-pattern AGA, the hairline is receding and the thinning is most notable in the frontotemporal region. AGA has a complex pathogenesis and relation of subcutaneous fat in the scalp region and the miniaturization of terminal hair follicles is vague. In this study, subcutaneous fat in the frontal scalp an important region for AGA is compared to the occipital scalp that is spared in AGA. METHOD: Our study is a cross-sectional study that has four groups. Male patient, female patient, male control, female control. Every group has 15 individuals. All of the people in the study are those referred to Rasoul Akram's dermatology clinic. The severity of alopecia is classified by Norwood scaling for male pattern AGA and Ludwig scaling for female pattern AGA. Subcutaneous tissue in the frontal and occipital regions is measured by ultrasonography. For evaluating the effect of aging on subcutaneous fat thickness, we subdivided any group into more than 40 years old and between 20 and 40 years old and compared these two subgroups. RESULTS: The mean age of the three groups of male patient, female patient, and female control is 40 y/o and the mean age of male control is 41 y/o. The mean subcutaneous fat layer thickness in frontal region in male patients group is 6.0 mm (more than 40 y/o = 6.6 mm, between 20 and 40 y/o = 5.5 mm), in female patients group 5.1 mm (more than 40 y/o = 5.7 mm, between 20 and 40 y/o = 4.6 mm), in the male control group is 4.4 mm (more than 40 y/o = 4.7 mm, between 20 and 40 y/o = 4 mm) and in the female control group is 4.1 mm (more than 40 y/o = 4.5 mm, between 20 and 40 y/o = 3.6 mm). The mean subcutaneous fat layer thickness in the occipital region in the male patient's group is 6.4 mm (more than 40 y/o = 6.7 mm, between 20 and 40 y/o = 6 mm), in the female patient's group 6.1 mm (more than 40 y/o = 6.5 mm, between 20 and 40 y/o = 5.7 mm), in the male control group is 6.3 mm (more than 40 y/o = 6.8 mm, between 20 and 40 y/o = 5.7 mm) and in the female control group is 6.2 mm (more than 40 y/o = 6.6 mm, between 20 and 40 y/o = 5.8 mm). CONCLUSION: This study demonstrates that the subcutaneous fat layer in the frontal region in both males and females is thicker in AGA patients than healthy group and the more severe the AGA, the thicker is subcutaneous layer in the frontal region. In the male patients group, the subcutaneous fat layer in the frontal region is thicker than in the female patients group but in the male and female control groups is not so different. The subcutaneous fat layer in the occipital region is thicker in older individuals in both patients and control groups but is not different when compared to AGA patients and control individuals.

High-frequency ultrasonography of the scalp: A comparison between androgenetic alopecia and healthy volunteers.

OBJECTIVE: This study aimed to assess differences in various scalp parameters between patients with androgenetic alopecia (AGA) and healthy volunteers using 22 MHz ultrasound. METHODS: Thirty patients with AGA (AGA group) and 30 healthy volunteers (control group) who visited the Department of Dermatology at the Second Affiliated Hospital of Soochow University from September 2021 to June 2022 were randomly selected. The patients with AGA met the diagnostic criteria outlined in the Chinese Guidelines for the Diagnosis and Treatment of Androgenetic Alopecia. The severity of alopecia was assessed for males between grades 2 and 4 on the Norwood-Hamilton scale, and for females between stages 2 and 3 on the Ludwig scale. No artificial interventions were conducted at the vertex, and all examination conditions remained consistent. Ultrasound examinations at 22 MHz were performed on the scalp at the vertex in both the AGA and control groups. Seven parameters were measured, namely, epidermis + dermis thickness, entire scalp thickness, subcutaneous tissue thickness, average follicle width, average follicle length, follicle count, and the presence of color flow signals in the subcutaneous tissue. The differences in these parameters were then compared. RESULTS: The AGA group showed reduced thickness of the entire scalp and subcutaneous tissue, narrower average follicle width, shorter average follicle length, lower hair follicle count, and fewer instances of color flow signals in the subcutaneous tissue at the vertex area (p < 0.05). CONCLUSION: High-frequency (22 MHz) ultrasonography can be employed to visualize the entrance echo, dermis, subcutaneous tissue, and hair follicles of the scalp, thereby providing imaging for the clinical assessment of hair loss.

Line-field confocal optical coherence tomography: Characteristic hints for the diagnosis of scarring alopecia due to lupus erythematodes: A preliminary study.

INTRODUCTION: Lupus erythematosus (LE) is an inflammatory autoimmune disease, that can affect the skin to varying degree. In particular, discoid LE (DLE) and the rare form of lupus panniculitis/profundus are associated with scarring alopecia. The heterogeneity of the clinical, dermatoscopic, and histologic presentation poses a major challenge to the clinician in the diagnosis and differential diagnosis of other forms of scarring alopecia. OBJECTIVE: While noninvasive imaging techniques using optical coherence tomography (OCT) and reflectance confocal microscopy (RCM) have proven to be helpful in the diagnosis of scarring alopecia in the context of LE, this study aimed to investigate line-field confocal OCT (LC-OCT) to identify characteristic features of cicatricial alopecia in LE. METHODS: Fifteen patients with cicatricial alopecia in LE were included and the most affected/inflamed areas of the scalp were prospectively examined. In analogy to histopathology and previously reported criteria in RCM, all images were evaluated according to seven established criteria and underwent descriptive analyses. RESULTS: LC-OCT revealed characteristic features of cicatricial alopecia, such as lymphocytic interface dermatitis (14/15; 93.3%) and basal cell vacuolization (13/15; 86.7%). The most impressive feature was the occurrence of prominent hyperreflective fibers in 14/15 patients (93.3%). CONCLUSION: LC-OCT imaging can noninvasively detect morphologic criteria such as lymphocytic and vacuolar interface dermatitis of cicatricial alopecia due to LE. In particular, the presence of hyperreflective collagen fibers appears to be a characteristic easily recognizable feature that may facilitate differential diagnosis with other forms of cicatricial alopecia. Further studies are mandatory to differentiate other forms of scarring alopecia.

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.

Hair Thickness Growth Effect of Adenosine Complex in Male-/Female-Patterned Hair Loss via Inhibition of Androgen Receptor Signaling.

Aging (senescence) is an unavoidable biological process that results in visible manifestations in all cutaneous tissues, including scalp skin and hair follicles. Previously, we evaluated the molecular function of adenosine in promoting alopecia treatment in vitro. To elucidate the differences in the molecular mechanisms between minoxidil (MNX) and adenosine, gene expression changes in dermal papilla cells were examined. The androgen receptor (AR) pathway was identified as a candidate target of adenosine for hair growth, and the anti-androgenic activity of adenosine was examined in vitro. In addition, ex vivo examination of human hair follicle organ cultures revealed that adenosine potently elongated the anagen stage. According to the severity of alopecia, the ratio of the two peaks (terminal hair area/vellus hair area) decreased continuously. We further investigated the adenosine hair growth promoting effect in vivo to examine the hair thickness growth effects of topical 5% MNX and the adenosine complex (0.75% adenosine, 1% penthenol, and 2% niacinamide; APN) in vivo. After 4 months of administration, both the MNX and APN group showed significant increases in hair density (MNX + 5.01% (p < 0.01), APN + 6.20% (p < 0.001)) and thickness (MNX + 5.14% (p < 0.001), APN + 10.32% (p < 0.001)). The inhibition of AR signaling via adenosine could have contributed to hair thickness growth. We suggest that the anti-androgenic effect of adenosine, along with the evaluation of hair thickness distribution, could help us to understand hair physiology and to investigate new approaches for drug development.

Bi-Allelic UQCRFS1 Variants Are Associated with Mitochondrial Complex III Deficiency, Cardiomyopathy, and Alopecia Totalis.

Isolated complex III (CIII) deficiencies are among the least frequently diagnosed mitochondrial disorders. Clinical symptoms range from isolated myopathy to severe multi-systemic disorders with early death and disability. To date, we know of pathogenic variants in genes encoding five out of 10 subunits and five out of 13 assembly factors of CIII. Here we describe rare bi-allelic variants in the gene of a catalytic subunit of CIII, UQCRFS1, which encodes the Rieske iron-sulfur protein, in two unrelated individuals. Affected children presented with low CIII activity in fibroblasts, lactic acidosis, fetal bradycardia, hypertrophic cardiomyopathy, and alopecia totalis. Studies in proband-derived fibroblasts showed a deleterious effect of the variants on UQCRFS1 protein abundance, mitochondrial import, CIII assembly, and cellular respiration. Complementation studies via lentiviral transduction and overexpression of wild-type UQCRFS1 restored mitochondrial function and rescued the cellular phenotype, confirming UQCRFS1 variants as causative for CIII deficiency. We demonstrate that mutations in UQCRFS1 can cause mitochondrial disease, and our results thereby expand the clinical and mutational spectrum of CIII deficiencies.

The histopathologic diagnosis of traction alopecia: An evidence-based model.

BACKGROUND: Traction alopecia (TA) is common, but histopathologic criteria for TA have not been objectively defined. OBJECTIVE: Determine whether the pauci-follicular unit (PFU) can be used as a diagnostic criterion for TA. Compared to a normal follicular unit (NFU), the PFU is a noninflamed follicular unit with an intact sebaceous gland but fewer than 2 follicles. METHODS: A retrospective review of 25 cases of TA and 25 cases of "normal scalp" was performed. Data included all follicles (by size and phase), sebaceous glands, and total follicular units. RESULTS: Comparing data (traction vs normal), we found a significantly higher number of PFUs in cases of TA (median 6 vs 0, P < .001), which can be used as a helpful and easily recognizable diagnostic tool in diagnosing cases of TA. LIMITATIONS: Comparison to other forms of alopecia was not performed. CONCLUSIONS: The number of PFUs in an alopecia biopsy can be used to establish the diagnosis of TA.

A comparative study of histopathologic features in alopecia areata and pattern hair loss.

BACKGROUND: When peribulbar infiltrates are absent, other histopathologic findings are necessary to distinguish alopecia areata (AA) from pattern hair loss (PHL). The purpose of this study is to determine which histopathologic features are most useful for differentiation. METHODS: A retrospective slide review was conducted of AA and PHL scalp biopsy specimens from 2014 to 2019 at a tertiary referral center. RESULTS: Ninety-six cases were retrieved, of which 38 were AA. Peribulbar infiltrates were identified in 24 AA (63.2%) cases. A catagen/telogen shift was observed more frequently in AA than PHL (25 cases, 65.5% vs. 10 cases, 17.2%; p ≤ 0.0001). Lymphocytes (4 cases, 10.5% vs. 1 case, 1.7%; p = 0.058) and melanin (25 cases, 65.8% vs. 5 cases, 8.6%; p ≤ 0.0001) in fibrous tracts were more common in AA. Apoptotic bodies within vellus hairs were more frequently identified in AA (32 cases, 84.2% vs. 37 cases, 63.8%; p = 0.030). Small dystrophic follicles were also more common in AA (16 cases, 42.1% vs. 1 case, 1.7%; p < 0.0001). CONCLUSIONS: Common features of AA other than peribulbar infiltrates include a catagen/telogen shift, melanin in fibrous tracts, and small dystrophic follicles. Practitioners should consider these features when distinguishing AA from PHL in specimens without peribulbar infiltrates. The retrospective design limits our ability to exclude multifactorial alopecia, such as telogen effluvium.

The modified HoVert (mHoVert) method improves diagnostic certainty compared to the St John's protocol for alopecia biopsy specimens: A retrospective single center study.

BACKGROUND: Access to vertical and transverse sections of a punch biopsy specimen improves the diagnosis of alopecia. Both two biopsy specimen and single-punch biopsy specimen techniques to visualize both transverse and vertical sections have been described. Their comparative diagnostic certainty is not known. We aimed to assess the diagnostic certainty of a modified HoVert (mHoVert) method, without direct immunofluorescence (DIF), compared to the St John's protocol, a two-biopsy technique with DIF. METHODS: Fifty-seven cases of alopecia processed using the St John's protocol and 60 cases of alopecia processed using mHoVert were reviewed. Diagnoses made were rated as certain/probable, possible, or uncertain, depending on the language in the histopathology report. Cases processed by the St John's protocol had final diagnosis and DIF result recorded. RESULTS: In the mHoVert group, significantly more diagnoses were certain/probable (66%, 95% confidence interval [CI]: 57%-75%), compared to 46% (95% CI: 36%-56%) of diagnoses in the St John's protocol group (p = 0.005). DIF result did not affect the final diagnosis in any of the 57 cases reviewed. CONCLUSIONS: DIF is not required in the diagnosis of most cases of alopecia. The mHoVert method provides more certain/probable diagnoses than the St John's protocol and can reduce cost and patient morbidity.

Clinical and dermatoscopic features of temporal triangular alopecia in infants.

OBJECTIVE: To summarize the clinical and dermatoscopic features of temporal triangular alopecia in infants and explore the clinical significance of dermatoscopy in the diagnosis of triangular alopecia temporalis in infants. METHODS: A retrospective analysis was performed on 20 children with temporal triangular alopecia diagnosed in the dermatology clinic of Tianjin Children's Hospital from January 2015 to December 2021. Dermatoscopy was performed on all children, and images were collected. RESULTS: The clinical features of 20 children were 15 males and five females, all of which were born immediately after birth; There were eight cases (40%) in the left temporal region, 10 cases (50%) in the right temporal region, one case (5%) in the head region, and one case (5%) in the occipital region; 19 cases were single (95%), one case was multiple (5%); There were 21 skin lesions, 15 triangular lesions (71.4%), four quasi-circular lesions (19%), and two lance-shaped lesions (9.5%). Trichoscopic features: The hair follicle opening in all skin lesions is normal, and the hair follicle opening can be seen with fluffy hair (vellus hair). The vellus hair is evenly distributed, and the length is diverse (both short and long vellus hair exist in the same hair loss area). There are 14 cases of white vellus hair (70%), five cases of white spots (25%), one case of honeycomb pigment pattern (5%), and one case of vascular dilation pattern (5%). CONCLUSION: Temporal triangular alopecia in infants has typical clinical and dermatoscopic characteristics, and the dermatoscopy can provide clinical basis for its diagnosis and differential diagnosis.

Linear alopecia in pediatrics: RCM and dermoscopy reveal diagnostic cues.

BACKGROUND: Alopecia areata (AA), trichotillomania (TM), nevus sebaceous (NS), and linear scleroderma en coup de sabre (LSCS) can all present with a patch of linear alopecia, making diagnosis challenging. The purpose of this study was to combine reflectance confocal microscopy (RCM) and dermoscopy in the diagnosis of these lesions in children. METHODS: A total of 36 patients with linear alopecia were enrolled, of whom 14 had AA, seven had TM, nine had NS, and six had LSCS. We evaluated the characteristics and distinguishing features of the four conditions using RCM and dermoscopy. RESULTS: The key to differential diagnosis was the dermal Hair follicle density in the dermis was decreased in AA, and the size and density of the follicular openings were normal in TM. In NS, the major features were petal-like and frogspawn-like structures. In LSCS, dermal papillary rings, sebaceous glands, and follicles were partially or completely missing, and abundant fibrous material was distributed in the dermis. Dermoscopy revealed alopecia, and all four conditions resulted in decreased hair density. AA patients exhibited yellow dots, black dots, and exclamation mark hairs. TM patients presented with irregularly broken hairs and blood spots. Both NS and LSCS patients exhibited an absence of follicular openings; NS patients demonstrated whitish and yellowish round structures, while an atrophic area with white patches, linear vessels, and no yellow or black dots was observed in LSCS patients CONCLUSION: RCM combined with dermoscopy can provide additional information on disease states and differentiate between AA, TM, NS, and LSCS.

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.