Skin Biopsy Specimens Research Articles

Nocardia huaxiensis sp. nov., an actinomycete isolated from human skin.

A novel actinomycete, designated as strain WCH-YHL-001T, was isolated from skin biopsy specimens of a patient at West China Hospital, Chengdu, Sichuan Province, PR China. The cells were Gram-positive, aerobic, heterotrophic and non-motile. They formed an extensive substrate with short aerial mycelia, whose branches fragmented into rod-shaped elements. Growth occurred at 10-40 °C, pH 5.0-12.0 and with NaCl concentrations of 0-4.0 % (w/v). The major cellular fatty acids of strain WCH-YHL-001T were C16 : 0, C18 : 1 ω9c, C18 : 0 10-methyl and summed feature 3. The predominant respiratory quinone was MK-8 (H4ω-cycl). The major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylinositol mannoside, unknown phospholipids and unidentified glycolipids. The diagnostic diamino acid of peptidoglycan was meso-diaminopimelic acid. The whole-cell sugar pattern consisted of arabinose and glucose. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain WCH-YHL-001T belonged to the genus Nocardia. The average nucleotide identity (ANI) and in silico DNA-DNA hybridization (isDDH) values between strain WCH-YHL-001T and type strains of Nocardia species were lower than the cut-offs (≥95-96 % for ANI and ≥70 % for isDDH) required to define a bacterial species. The genomic DNA G+C content was 67.8 mol%. Phylogenetic, physiological and chemotaxonomic data suggested that strain WCH-YHL-001T represented a novel species of the genus Nocardia, for which the name Nocardia huaxiensis sp. nov. is proposed, with the type strain WCH-YHL-001T (=GDMCC 4.181T=JCM 34475 T=NBRC 114973T).

Successful treatment of a presumed autoimmune subepidermal bullous dermatosis in a horse

AbstractAutoimmune subepidermal bullous dermatoses are rarely described in the horse. Few reported cases have not been cured favourably. A 15‐year‐old male horse was presented with general ulcerative and blistering lesions on skin and oral cavity. Histopathological evaluation of skin biopsy specimens revealed dermal and epidermal separation with subepidermal vesicles and mild infiltration of inflammatory cells (predominantly mononuclear cells). Clinical, historical and histopathological examinations demonstrated a subepidermal vesicular dermatosis. Treatment was initiated with dexamethasone at 0.05 mg/kg IM daily for 3 days, followed by oral prednisolone at 1 mg/kg daily for 2 months. A complete resolution of clinical signs was observed after 2 months, and no recurrence was observed after 24 months follow‐up. No adverse effects were observed.

Bilateral Chilblain-like Lesions of the Toes Characterized by Microvascular Remodeling in Adolescents During the COVID-19 Pandemic

Chilblain-like lesions have been one of the most frequently described cutaneous manifestations during the COVID-19 pandemic. Their etiopathogenesis, including the role of SARS-CoV-2, remains elusive. To examine the association of chilblain-like lesions with SARS-CoV-2 infection. This prospective case series enrolled 17 adolescents who presented with chilblain-like lesions from April 1 to June 30, 2020, at a tertiary referral academic hospital in Italy. Macroscopic (clinical and dermoscopic) and microscopic (histopathologic) analysis contributed to a thorough understanding of the lesions. Nasopharyngeal swab, serologic testing, and in situ hybridization of the skin biopsy specimens were performed to test for SARS-CoV-2 infection. Laboratory tests explored signs of systemic inflammation or thrombophilia. Structural changes in peripheral microcirculation were investigated by capillaroscopy. Of the 17 adolescents (9 [52.9%] male; median [interquartile range] age, 13.2 [12.5-14.3] years) enrolled during the first wave of the COVID-19 pandemic, 16 (94.1%) had bilaterally localized distal erythematous or cyanotic lesions. A triad of red dots (16 [100%]), white rosettes (11 [68.8%]), and white streaks (10 [62.5%]) characterized the dermoscopic picture. Histologic analysis revealed a remodeling of the dermal blood vessels with a lobular arrangement, wall thickening, and a mild perivascular lymphocytic infiltrate. SARS-CoV-2 infection was excluded by molecular and serologic testing. In situ hybridization did not highlight the viral genome in the lesions. This study delineated the clinical, histologic, and laboratory features of chilblain-like lesions that emerged during the COVID-19 pandemic, and its findings do not support their association with SARS-CoV-2 infection. The lesions occurred in otherwise healthy adolescents, had a long but benign course to self-resolution, and were characterized by a microvascular remodeling with perivascular lymphocytic infiltrate but no other signs of vasculitis. These results suggest that chilblain-like lesions do not imply a concomitant SARS-CoV-2 infection. Ongoing studies will help clarify the etiopathogenic mechanisms.

Advantages of an Automated Method Compared With Manual Methods for the Quantification of Intraepidermal Nerve Fiber in Skin Biopsy.

Intraepidermal nerve fiber density (IENFD) measurements in skin biopsy are performed manually by 1–3 operators. To improve diagnostic accuracy and applicability in clinical practice, we developed an automated method for fast IENFD determination with low operator-dependency. Sixty skin biopsy specimens were stained with the axonal marker PGP9.5 and imaged using a widefield fluorescence microscope. IENFD was first determined manually by 3 independent observers. Subsequently, images were processed in their Z-max projection and the intradermal line was delineated automatically. IENFD was calculated automatically (fluorescent images automated counting [FIAC]) and compared with manual counting on the same fluorescence images (fluorescent images manual counting [FIMC]), and with classical manual counting (CMC) data. A FIMC showed lower variability among observers compared with CMC (interclass correlation [ICC] = 0.996 vs 0.950). FIMC and FIAC showed high reliability (ICC = 0.999). A moderate-to-high (ICC = 0.705) was observed between CMC and FIAC counting. The algorithm process took on average 15 seconds to perform FIAC counting, compared with 10 minutes for FIMC counting. This automated method rapidly and reliably detects small nerve fibers in skin biopsies with clear advantages over the classical manual technique.

Tissue-Resident Memory CD8+ T Cells From Skin Differentiate Psoriatic Arthritis From Psoriasis.

ObjectiveTo compare immune cell phenotype and function in psoriatic arthritis (PsA) versus psoriasis in order to better understand the pathogenesis of PsA.MethodsIn‐depth immunophenotyping of different T cell and dendritic cell subsets was performed in patients with PsA, psoriasis, or axial spondyloarthritis and healthy controls. Subsequently, we analyzed cells from peripheral blood, synovial fluid (SF), and skin biopsy specimens using flow cytometry, along with high‐throughput transcriptome analyses and functional assays on the specific cell populations that appeared to differentiate PsA from psoriasis.ResultsCompared to healthy controls, the peripheral blood of patients with PsA was characterized by an increase in regulatory CD4+ T cells and interleukin‐17A (IL‐17A) and IL‐22 coproducing CD8+ T cells. One population specifically differentiated PsA from psoriasis: i.e., CD8+CCR10+ T cells were enriched in PsA. CD8+CCR10+ T cells expressed high levels of DNAX accessory molecule 1 and were effector memory cells that coexpressed skin‐homing receptors CCR4 and cutaneous lymphocyte antigen. CD8+CCR10+ T cells were detected under inflammatory and homeostatic conditions in skin, but were not enriched in SF. Gene profiling further revealed that CD8+CCR10+ T cells expressed GATA3, FOXP3, and core transcriptional signature of tissue‐resident memory T cells, including CD103. Specific genes, including RORC, IFNAR1, and ERAP1, were up‐regulated in PsA compared to psoriasis. CD8+CCR10+ T cells were endowed with a Tc2/22‐like cytokine profile, lacked cytotoxic potential, and displayed overall regulatory function.ConclusionTissue‐resident memory CD8+ T cells derived from the skin are enhanced in the circulation of patients with PsA compared to patients with psoriasis alone. This may indicate that aberrances in cutaneous tissue homeostasis contribute to arthritis development.

POS0326 ROLE OF THE IL-25 / IL-17RB AXIS IN TH9 POLARIZATION IN PATIENTS WITH PROGRESSIVE SYSTEMIC SCLEROSIS

Background:Systemic sclerosis (SSc) is an inflammatory connective tissue disease leading to chronic and progressive fibrosis, typically affecting the skin and internal organs. The alteration of both innate and adaptive immune responses plays a pivotal role in SSc pathophysiology, although it has not yet been fully elucidated [1].Recent findings have demonstrated interleukin (IL)-9 overexpression and significant group 2 innate lymphoid cells (ILC2) expansion in patients with SSc. Th9-ILC2-mast cells axis seems to be involved in SSc tissue damage and in the induction of fibrosis [2]. Activation and production of IL-9 by Th9 cells are promoted by transforming growth factor (TGF)-β, thymic stromal lymphopoietin (TSLP), IL-25 and IL-33. Thus, the IL-25 / IL-17RB pathway would act as a key player in SSc.Objectives:The purpose of this study was to evaluate the role of the IL-25 / IL-17RB axis as a driver in Th9 polarization and ILC2 expansion and polarization in SSc patients.Methods:26 patients were enrolled in this study. Peripheral blood and skin biopsy specimens were obtained from SSc patients. PBMCs were isolated and incubated with and without recombinant (r)IL-25 for 24-48-72 hours and the frequencies of Th9 cells, Th17 cells and ILC2 were assessed by flow cytometry analysis. Moreover, the ex vivo expression of IL-17RB in ILC2 was also assessed. Immunofluorescence analysis was performed on biopsy skin samples to evaluate IL-17RB expression in ILC2.Results:In SSc samples, Th9 cells frequency progressively increased after stimulation with rIL-25, compared to healthy controls in which IL-9 frequency decreased over time regardless of rIL-25.Simultaneously, we evaluated the role of the IL-25 / IL-17RB axis in Th17 cells.In the SSc pool, the initially low rate of IL-17 increased at 72 hours after stimulation with rIL-25. In unstimulated SSc samples, the initially higher IL-17 rate decreased at 72 hours; conversely, it was consistently low in healthy controls, at both baseline and stimulated conditions.Our results confirmed the presence of IL-25-dependent clonal ILC2 expansion, suggesting a greater and progressive expansion over time in patients with SSc, compared to controls.Interestingly, increased IL-17RB expression was found in circulating ILC2 from SSc patients supporting the characterization of ILC2 inflammatory phenotype.Consistently, immunofluorescence on the skin of SSc patients showed a marked infiltrate of CD3-GATA3+ IL-17RB+ cells, confirming the presence of the activated inflammatory phenotype ILC2, absent in skin biopsies of healthy controls (Figure 1).Conclusion:These preliminary data suggest an active role of the IL-25/IL-17RB axis in SSc. It results in Th9 polarization and Th17 clonal expansion, inducing the production of IL-9 and, to a lesser extent, IL-17. Moreover, in addition to promoting Th9-mediated ILC2 differentiation, IL-25 directs the polarization of ILC2 towards the inflammatory phenotype.

Prediction of the Risk of Alopecia Areata Progressing to Alopecia Totalis and Alopecia Universalis: Biomarker Development with Bioinformatics Analysis and Machine Learning

Background: Alopecia areata (AA) is an autoimmune disease typified by nonscarring hair loss with a variable clinical course. Although there is an increased understanding of AA pathogenesis and progress in its treatments, the outcome of AA patients remains unfavorable, especially when they are progressing to the subtypes of alopecia totalis (AT) or alopecia universalis (AU). Thus, identifying biomarkers that reflect the risk of AA progressing to AT or AU could lead to better interventions for AA patients. Methods: In this study, we conducted bioinformatics analyses to select key genes that correlated to AU or AT based on the whole-genome gene expression of 122 human scalp skin biopsy specimens obtained from NCBI-GEO GSE68801. Then, we built a biomarker using 8 different machine learning (ML) algorithms based on the key genes selected by bioinformatics analyses. Results: We identified 4 key genes that significantly increased (CD28) or decreased (HOXC13, KRTAP1-3, and GPRC5D) in AA tissues, especially in the subtypes of AT and AU. Besides, the predictive accuracy (area under the curve [AUC] value) of the prediction models for forecasting AA patients progressing to AT/AU models reached 90.7% (87.9%) by logistic regression, 93.8% (79.9%) by classification trees, 100.0% (76.3%) by random forest, 96.9% (76.3%) by support vector machine, 83.5% (79.9%) by K-nearest neighbors, 97.1% (87.3%) by XGBoost, and 93.3% (80.6%) by neural network algorithms for the training (internal validation) cohort. Besides, 2 molecule drugs, azacitidine and anisomycin, were identified by Cmap database. They might have the potential therapeutic effects on AA patients with high risk of progressing to AT/AU. Conclusions: In the present study, we conducted high accuracy models for predicting the risk of AA patients progressing to AT or AU, which may be important in facilitating personalized therapeutic strategies and clinical management for different AA patients.

Detection of coxsackievirus A6 in formalin-fixed, paraffin-embedded skin biopsy specimens using immunohistochemistry and real-time reverse-transcriptase PCR

BackgroundHand, foot, and mouth disease (HFMD), classically a childhood viral infection, has an atypical and severe clinical presentation in adults. Coxsackievirus A6 is a leading cause of atypical HFMD, but current diagnostic methods utilizing formalin-fixed, paraffin-embedded skin biopsy specimens often lack sensitivity and specificity. MethodsFormalin-fixed, paraffin-embedded skin biopsies from seven case patients with clinical and histopathological suspicion of atypical HFMD were evaluated by coxsackievirus A6 (CVA6) immunohistochemistry, enterovirus-specific conventional reverse transcriptase-PCR with subsequent Sanger sequencing targeting the 5’UTR, and CVA6-specific real-time PCR targeting the VP1 gene. ResultsThe CVA6-specific antibody demonstrated appropriate antigen distribution and staining intensity in keratinocytes in all cases. Conventional RT-PCR and sequencing also detected the presence of enterovirus, and CVA6-specific real-time RT-PCR analysis identified CVA6. ConclusionApplying these immunohistochemistry and molecular techniques to formalin-fixed, paraffin-embedded tissues, CVA6 was determined to be the causative infectious agent in seven cases of atypical hand, foot, and mouth disease.

B cells join T cell clusters in the host response to recurrent herpes simplex virus 2 infection.

Recurrent genital herpes lesions are infiltrated by various leukocytes, yet the role of B cell subsets in this process is unknown. In this issue of the JCI, Ford et al. describe the presence and antibody-secreting role of local B cell populations in herpes simplex virus 2 (HSV-2) recurrent lesions. The authors analyzed a comprehensive array of sequential skin biopsy specimens from HSV-2-infected patients over time and at various stages of infection. Using immunofluorescence and in situ hybridization, the authors show the presence of rare IgD+ naive B cells and IgG-expressing antibody-secreting cells (ASCs) in recurrent HSV-2 lesions embedded in CD4+ T cell-rich dermal immune infiltrates, levels of which transiently increase during lesion reactivation and healing. Notably, local increases in HSV-2-specific antibodies in recurrent lesions were detected, whereas serum HSV-2 antibody levels remained stable. Future research is needed to understand the precise role of these tissue-visiting B cells in disease resolution.

Assessment of Diagnostic Strategy for Mucous Membrane Pemphigoid

An accurate diagnosis of mucous membrane pemphigoid (MMP) is essential to reduce diagnostic and therapeutic delay. To assess the diagnostic accuracy of direct immunofluorescence microscopy on mucosal biopsy specimens and immunoserology in a large cohort of patients with suspected MMP. This retrospective cohort study was carried out in a single tertiary care center for blistering diseases between January 2002 and March 2019. Eligible participants were patients with suspected MMP and paired data on at least a mucosal biopsy specimen for direct immunofluorescence microscopy (DIF) and indirect immunofluorescence microscopy (IIF) on a human salt-split skin substrate (SSS). In addition, an optional DIF test on a skin biopsy specimen and one or more performed routine immunoserologic tests were analyzed. Data analysis was conducted from April 2019, to June 2020. Diagnostic accuracy of DIF, IIF SSS, and immunoblot for BP180 and BP230. Of the 787 participants, 121 (15.4%) received the diagnosis of MMP (50 men [41.3%], 71 women [58.7%]; mean [SD] age at diagnosis, 60.1 [17.7] years). Sixty-seven of the patients with MMP (55.4%) had monosite involvement, of which oral site was the most frequently affected (51 [42.1%]). No significant difference was found between the sensitivity of DIF on a perilesional buccal biopsy and a normal buccal biopsy (89.3% vs 76.7%). Three patients with solitary ocular involvement showed a positive DIF of only the oral mucosa. In 6 patients with a negative mucosal DIF, a skin biopsy confirmed diagnosis of MMP. Overall, IIF SSS was less sensitive (44.6%), but highly specific (98.9%). The sensitivity of immunoblot (66.1%) was higher compared to SSS, but with lower specificity (91.3%). This comparative diagnostic accuracy study of a cohort of 787 patients found a high sensitivity of a mucosal DIF biopsy for diagnosis of MMP, and lower sensitivity of serologic analysis. A biopsy can be taken from either perilesional or normal buccal mucosa. An additional DIF biopsy of another mucosal site or of affected or unaffected skin may increase the diagnostic yield and is recommended in patients with negative DIF results and high clinical suspicion.

647 Clinical analysis of Hidroacanthoma simplex

Objective: To investigate the clinical, histopathological findings, immunohistochemical features and therapeutic methods of hidroacanthoma simplex (HS). Methods: The clinical presentation, histological findings, immunohistochemical features and therapeutic methods of 5 patients with HS diagnosed between January 2015 and August 2020 in the Second Affiliated Hospital of Xi”an Jiaotong University and 17 patients with HS reported in the literature searched in CNKI were retrospectively analyzed. Results: Mean age at onset of the skin eruption was 62 years (range 36-86 years), 14 patients (63.6%) were female, and the skin lesion had been present for a mean of 7.84 years (range 5 months-50 years). Typical clinical findings were keratotic plaques mainly distributed the lower extremities and the trunk. Skin biopsy specimens from 22 patients showed the “Jadassohn phenomenon” and was composed of bland basaloid cells that were smaller than neighboring epidermal keratinocytes. Intracytoplasmic glycogen and occasional ductal structures within the nests of cells were also found. And one case (4.5%) was diagnosed as malignant HS. Immunohistochemically, the cytoplasm of some tumor cells showed a positive reaction to EMA and the normal ductal structure showed a positive reaction of CEA. Most patients (81.8%) chossed surgical resection and no recurrence and malignant transformation in follow-up. Conclusion: HS is a rare intraepidermal benign tumor, but it has risk of malignant transformation. And this disease mostly occurs in female patients, which is different from previous literature reports. For dermatologists, it is extremely important to correctly recognize and diagnose this disease.

Assessment of Various Laboratory Diagnostic Methods in Diagnosis of Cutaneous Tuberculosis. A Study from A Tertiary Care Hospital of North India

Cutaneous tuberculosis (CTB) is the rarest case of extrapulmonary TB comprising 2% of total cases. It’s often a challenge both clinically and diagnostically. 1) To determine prevalence, age & gender-wise distribution of CTB. 2) To assess various diagnostic, microbiological modalities for the diagnosis of CTB. 76 skin biopsy specimens from suspected CTB lesions were analysed using following methods – Acid-fast Bacilli (AFB) staining (Ziehl-Neelsen method), growth of mycobacteria in culture (Lowenstein-Jensen media), and Gene Xpert MTB/RIF, Histopathological (H&E staining). Of the 76 specimens, 44 were males and 32 were females. The most commonly affected age group was 40–59 years. Infections were least common in 0-19 years age group. AFB was not seen in any of the primary smears. 10 were confirmed as CTB by the recovery of Mycobacterium in solid culture. Of the 10 culture positives, 9 were confirmed as MTB, and 1 was found to be NTM. Staining of 10 culture positive specimens revealed acid fast, beaded rods. Detection of MTB by Gene Xpert gave positive result in 9 cases with all RIF sensitive. All 9 PCR confirmed cases were also culture positive, all 9 were slow growers with a minimum of 5 weeks required for growth on the LJ slant. PCR is the test of choice and should be performed on all specimens of suspected CTB. However when coupled with the “gold standard” culture method, the diagnostic accuracy improves. Also, further, culture helps in identification and isolation of NTM’s.

A STUDY OF CONCORDANCE BETWEEN CLINICAL AND HISTOPATHOLOGICAL DIAGNOSIS IN CASES OF LEPROSY WITH RELEVANCE TO THERAPY

AIMS AND OBJECTIVES:To achieve the goal of WHO new global strategy of 2016-20 to decrease the case load, early and proper diagnosis for treatment and avoiding disability. Examination of a biopsy specimen of skin or nerve biopsies for histopathology can be a valuable aid for reaching conrmatory diagnosis of leprosy and its subtypes, differential diagnosis, prognosis of the disease and assessment or regression of the disease in patient under treatment and also for research, especially in early and borderline cases. The aim of this study was to correlate histopathological diagnosis of skin biopsies with clinical diagnosis of leprosy. This study was conducted to seek out and highlight the efcacy of the test and therefore its importance in current diagnostic scenario. MATERIALS AND METHODS: The retrospective study was carried out on the skin biopsies from untreated cases of leprosy seen in the Department of Dermatology and reported in the histopathology section of the Department of Pathology, School of Tropical Medicine, Calcutta between August 2016 to June 2019. HE sections of skin biopsies of all the cases of leprosy were examined for Epidermal atrophy, epithelioid granulomas, number & distribution of lymphocytes, histiocytes & foam cells; Inltration of nerves, blood vessels and adnexa; Grenz zone. Sections stained with ZN were examined for lepra bacilli in all cases. Histopathological ndings were graded into (TT), (BT), (BB), (BL) and (LL) according to Ridley and Jopling scale. Clinical diagnosis of the leprosy cases (as provided by department of Dermatology) using Ridley & Jopling scale was correlated with the results of histopathologic examinaton of their respective biopsies. RESULTS: Out of total cases in the OPD over Aug 2016 to June 2019,115 were sent for biopsy with conclusive clinical diagnosis of Leprosy out of which 45 cases came with the positive diagnosis of leprosy out of which TT(12) , BT(12), BB(3), BL(2),LL(8), Histoid(8). In 2016-17 the accuracy of clinichistopathological correlation was 35.4% ,41.3%in 2018 ,36.36% till mid 2019 . The discrepancy with the HPE refuting clinical diagnosis was 48.38% in 2017 ,58.62% in 2018 ,63.63% in mid 2019}. Histoid leprosy and ENL were 10 out of 31 cases in 2018-19 while 2cases were histopathologically diagnosed as leprosy despite having Sarcoidosis / Gr. Annulare clinically. Although the clinico- CONCLUSION: histopathological agreement in this study leaves much to be desired for prompt diagnosis, the disparity in correlation does decrease the chances of false positives and helps in better nalising the diagnosis for better treatment, Prognosis, follow-up and monitoring of the diseases are also aided by correct histopathological diagnosis especially in case of early and borderline cases of leprosy

Epithelialized tunnels are a source of inflammation in hidradenitis suppurativa

Hidradenitis suppurativa (HS), also known as acne inversa, is a chronic, painful, and burdensome inflammatory disease manifesting in nodules and abscesses, with progression to chronically draining tunnels in later-stage disease. We sought to determine whether HS tunnels are immunologically active participants in disease activity. Skin biopsy specimens were obtained by using ultrasound guidance in untreated patients with HS and those enrolled in an open-label study of brodalumab (ClinicalTrials.gov identifier NCT03960268) for patients with moderate-to-severe HS. Immunohistochemistry of HS biopsy specimens demonstrated that the epithelialized HS tunnels recapitulate the psoriasiform epidermal hyperplasia morphology of the overlying epidermis, displaying molecular inflammation, including S100A7 (psoriasin) positivity, as well as features of epidermal skin, including loricrin, filaggrin, lipocalin-2, and Melan-A positive cells. Tunnels were associated with increased infiltration of T cells, dendritic cells, and neutrophils; formation of neutrophil extracellular traps, and increased expression of psoriasiform proinflammatory cytokines. Unsupervised hierarchical clustering demonstrated a separation of HS samples based on the presence or absence of tunnels. Tunnels isolated by microdissection had higher levels of epithelium-derived inflammatory cytokines compared with the overlying epidermis and healthy controls. Clinically, the size and draining of the tunnels were decreased with treatment with the IL-17RA antagonist brodalumab. These data suggest that tunnels are a source of inflammation in HS.

PATTERNS OF HISTOMORPHOLOGICAL VARIANTS OF SKIN DISEASES IN A RURAL TERTIARY CARE CENTRE

Background: Skin biopsy is a common procedure in Dermatology practice. The usual intent of skin biopsy is to further characterize the nature of a skin growth or eruption and assist in diagnosis by allowing histopathological evaluation of a tissue sample. Although histopathology remains the gold standard for most dermatologic diagnoses, it must be recognized that not all lesions are amenable to definitive specific histological diagnosis1.
 Material & Methods: The present study is undertaken in the department of Pathology, Index Medical College Hospital and Research Center, Indore (M.P). This was a cross sectional observational study which included skin biopsy specimen from 122 cases reported for histopathological evaluation attending Skin & VD OPD of the institute from June 2018 to Feb 2020. On the basis of histopathological features these skin disorders were classified in different groups as per Lever’s classification2.
 Results: out of 116 cases included in the study, maximum cases belonged to group III (n=43) followed by group V (n=38), group IV (n=11), group I (n=7), group II (n=7), group VI (n=7) and group VII (n=3). Overall most common disease observed was Psoriasis followed by Leprosy. Highest number of cases were found in age group 41-50 years (n=25) and clinicopathological correlation was seen in 79.09% cases.
 Conclusion: The skin biopsy and subsequent histopathological examination has been proved as gold standard for identifying a specific dermatoses and appropriate management, being most cost effective tool.
 Keywords: Skin, Histopathology, Psoriasis, Leprosy

Immunoglobulin M pemphigoid

Pemphigoid diseases are a heterogeneous group of autoimmune blistering disorders characterized by predominant deposition of immunoglobulin G or immunoglobulin A autoantibodies against structural proteins of the dermoepidermal junction (DEJ). Sole linear immunoglobulin M (IgM) deposits at the DEJ in pemphigoid diseases have been observed; however, IgM-specific target antigens have not been identified. Characterization of patients with IgM pemphigoid. Skin biopsy specimens and sera from IgM-positive patients were assessed using histopathology, direct and indirect immunofluorescence microscopy, enzyme-linked immunosorbent assays, immunoblotting, cryosection assay, complement fixation test, and internalization assays. Tissue-bound linear IgM deposits along the DEJ and circulating IgM autoantibodies against type XVII collagen (Col17) were detected. These circulating IgM autoantibodies showed no complement activating or blister inducing capacity, but the ability of Col17 internalization exvivo. Limited number of patients. This study provides further evidence for the role of IgM autoantibodies in pemphigoid disease and highlights Col17 as a target antigen in IgM pemphigoid.

Histopathological Evaluation of Scar Tissue and Adjacent Non-Involved Skin

Background: Previous researches declared that scars are the end outcome of the natural healing and reparative process as a result of dermal fibrotic scar formation post inflammation. Few studies were conducted to explain the role of perilesional area in abnormal scar pathogenesis. Objective: To study the histopathological changes in different types of scars and adjacent apparently non-involved skin. Hopefully, this insight can set the route for newer therapeutic approaches. Patients and Methods: This prospective case control study was carried out on 30 participants divided into three groups. Group1 included ten keloid biopsies, Group2 included ten hypertrophic scar biopsies and Group3 included ten atrophic scar biopsies. Clinical assessment of scars was done. Skin biopsy specimens were taken from lesional and perilesional skin and sent to histopathology laboratory. Results: Increased epidermal thickening was significantly noted in 80% of perilesional specimens of keloid scar and that was significantly higher than lesional skin, while dermal fibroblasts/myofibroblasts were mildly increased in 80% of specimens and were associated with severe perivascular inflammatory infiltrates in 70% of perilesional specimens. Myofibroblasts/ fibroblasts and perivascular infiltrate were significantly higher in perilesional than lesional keloid skin. Epidermal thickening was significantly increased in all perilesional specimens of hypertrophic scar and was significantly higher than lesional skin. In dermis, hair follicles and sebaceous glands were identified in 100% of perilesional skin. Dermal cellularity was significantly mildly increased in 100% of perilesional specimens of atrophic and hypertrophic scars and both were significantly higher than normal skin. Conclusion: Perilesional area is a shadow area and may be a main player in abnormal scar pathogenesis and could be responsible for progression or regression of scar.

Histopathological Evaluation of Scar Tissue and Adjacent Non-Involved Skin

Background: Previous researches declared that scars are the end outcome of the natural healing and reparative process as a result of dermal fibrotic scar formation post inflammation. Few studies were conducted to explain the role of perilesional area in abnormal scar pathogenesis. Objective: To study the histopathological changes in different types of scars and adjacent apparently non-involved skin. Hopefully, this insight can set the route for newer therapeutic approaches. Patients and Methods: This prospective case control study was carried out on 30 participants divided into three groups. Group1 included ten keloid biopsies, Group2 included ten hypertrophic scar biopsies and Group3 included ten atrophic scar biopsies. Clinical assessment of scars was done. Skin biopsy specimens were taken from lesional and perilesional skin and sent to histopathology laboratory. Results: Increased epidermal thickening was significantly noted in 80% of perilesional specimens of keloid scar and that was significantly higher than lesional skin, while dermal fibroblasts/myofibroblasts were mildly increased in 80% of specimens and were associated with severe perivascular inflammatory infiltrates in 70% of perilesional specimens. Myofibroblasts/ fibroblasts and perivascular infiltrate were significantly higher in perilesional than lesional keloid skin. Epidermal thickening was significantly increased in all perilesional specimens of hypertrophic scar and was significantly higher than lesional skin. In dermis, hair follicles and sebaceous glands were identified in 100% of perilesional skin. Dermal cellularity was significantly mildly increased in 100% of perilesional specimens of atrophic and hypertrophic scars and both were significantly higher than normal skin. Conclusion: Perilesional area is a shadow area and may be a main player in abnormal scar pathogenesis and could be responsible for progression or regression of scar.

Histopathological spectrum and clinicopathological concordance of nonneoplastic skin lesions at a teaching hospital in South-Eastern Nigeria: A 16-year retrospective study

Background: Only a few clinicopathological epidemiological studies detailing histopathologically diagnosed skin diseases have been carried out in Nigeria. Thus, the aim of this study was to retrospectively survey the histopathological spectrum and clinicopathological concordance of histopathologically diagnosed skin diseases in Nigeria over a 16-year period. Materials and Methods: This study involved the assessment of all skin biopsy specimens received at the Department of Histopathology, Nnamdi Azikiwe University Teaching Hospital, Nnewi, Nigeria, from January 2004 to December 2019. Histopathological diagnoses based on these skin biopsies were made by consultant anatomical pathologists using routine hematoxylin and eosin-stained slides. All relevant demographic data and provisional clinical diagnoses were obtained from the histopathology laboratory requisition forms provided with the specimens. The skin lesions were then classified according to the International Classification of Diseases, Tenth revision (2019). Results: A total of 347 skin lesion biopsy specimens were included in this study. Most of the patients were aged 20–39 years old, with a mean age of 34.2 years. One hundred and forty-eight (42.7%) of the patients were males, whereas 199 (57.3%) were females. The most common 1CD-10 categories were disorders of skin appendages (105/347 [30.3%] cases) and papulo squamous disorders (81/347 [23.3%] cases), whereas the least common category was radiation-related disorders of the skin (2/347 [0.6%] cases). The most common disorder of the skin appendage was epidermal inclusion cyst (71/105 [71.4%] cases). Lichen planus was the most common papulosquamous disorder observed (26/81 [32.1%] cases). Only 202 cases included records of the biopsy site. The lower extremities were the most common sites of involvement (48/202 [23.8%] cases). The clinical diagnosis was concordant with the histopathological diagnosis in 55.3% of the cases, whereas it was discordant in the remaining cases. Conclusion: The most common skin diseases observed in this study were disorders of skin appendages and papulosquamous lesions. Our study provides baseline data for future population-targeted studies of nonneoplastic skin diseases.

Treatment of Discoid Lupus Erythematosus in a Dog with Human Intravenous Immunoglobulin

Background: Discoid lupus erythematosus (DLE) is a common canine autoimmune skin disease, in which systemic manifestations are absent. Skin Lesions are usually present on the nasal planum, and characterised by erythema, depigmentation, erosion, ulceration, and crusting. The diagnosis is based on histopathological results, which should demonstrate lymphoplasmacytic lichenoid-interface dermatitis. Human intravenous immunoglobulin (hIVIg) has been used in veterinary medicine to treat cutaneous diseases including erythema multiforme, PF, and severe adverse cutaneous drug reactions. In human medicine, it has been effective to treat DLE. This report firstly describes the clinical response to hIVIg in a dog with DLE resistant to common immunosuppressive drugs.Case: A 5-year-old, intact female Shih Tzu presented with a 1-month history of slowly progressive black crusting on the nasal planum, chin, and claw. Based on the results of a dermatologic examination, superficial pyoderma was diagnosed. The skin lesions did not improve during and after anti-infective treatment. After removing the crusts, a skin biopsy was obtained from the muzzle. Histopathology of lesional skin biopsy specimens revealed lymphoplasmacytic interface dermatitis at the dermoepidermal junction. Microscopic examination also revealed vacuolar changes and pigmentary incontinence of the basal layer as a lichenoid tissue reaction. No mites or fungi were detected on the skin section. The absence of acantholytic cells excluded pemphigus foliaceus, which is also characterised by the lesions of the nasal planum. Based on the distribution of the lesions, histopathology and exclusion of other dermatoses, the dog was diagnosed with DLE. The skin lesions temporarily improved after treatment with prednisolone (2 mg/kg PO q12h). However, after tapering the dose of prednisolone, new black crusts developed on the nasal planum and claw. Although the dog was successively treated with other immunosuppressive drugs, including azathioprine, cyclosporin with dexamethasone, and mycophenolate mofetil, black crusts still remained. Due to the low efficacy of these immunosuppressive drugs, hIVIg was administered at 0.5 g/kg once daily for 4 days, for a total dose of 2 g/kg. During hIVIg administration, the crusted lesions gradually improved. After the hIVIg administration, the dog was treated with prednisolone (1 mg/kg PO q12h). The lesions were almost in complete remission at 21 days after an additional application of prednisolone. The skin lesions did not recur, and the treatment was eventually discontinued after 6 weeks of additional prednisolone application.Discussion: The standard treatment of canine DLE includes glucocorticoids, and second-line immunosuppressive drugs, such as azathioprine and cyclosporine, are usually added in cases resistant to steroids. This case suggests that hIVIg may be beneficial as an adjunctive treatment option for canine DLE, especially when the application of standard immunosuppressive drugs is limited due to adverse effects or low efficacy. There is evidence from several studies that the steroid-sparing effect of hIVIg is significant in human patients. In the current case, the effective dose of prednisolone was reduced to 2 mg/kg/day after hIVIg administration, and prednisolone therapy was finally discontinued completely. The hIVIg appears to lower the daily steroid dose requirement in this dog. Keywords: autoimmune skin disease, discoid lupus erythematosus, canine dermatology, immunosuppressive drug, human intravenous immunoglobulin.