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A unique dermatopathology incident arose after administration of the mRNA-1273 SARS-CoV-2 (Moderna) vaccine. Specifically, a transient purpuric interface dermatitis occurred 5 days post-second vaccine with the presentation of erythematous papules with erythema multiforme-type findings. A patient developed purpuric interface dermatitis with micro-vesiculation post-vaccination which ultimately resolved without sequelae.

Abstract A 39‐year‐old man presented with an acneiform facial eruption, bilateral vegetating erythematous plaques on the inguinal folds, focal palmoplantar keratoderma, keratotic violaceous plaques of the dorsum of both hands, and whitish striated lesions on the oral mucosa. Laboratory work‐up showed high titre of ANAs, anti‐SSA(Ro) and anti‐SSB(La) and hypocomplementemia (low C4). Three skin biopsies from different locations were suggestive of cutaneous lupus erythematosus (CLE). Treatment with hydroxychloroquine 400 mg/day plus topical and systemic corticosteroids led to significant clinical improvement after 2 months. Lupus erythematosus comedonicus is a form of discoid CLE and clinically characterized by acneiform lesions. Vegetating lesions, named as lupus erythematosus vegetans, are extremely rare in CLE. The combination of both manifestations in our patient may be better described as ‘lupus erythematous comedonicus and vegetans’.

Equine herpesvirus-5 (EHV-5) is commonly found in healthy asymptomatic horses worldwide. Although a cause-and-effect relationship has not been thoroughly determined, this virus has been associated with several disease conditions including equine multinodular pulmonary fibrosis (EMPF) and 1 case of interface dermatitis. The authors searched the New York State Animal Health Diagnostic Center database for cases of equine interface dermatitis between 2007 and 2022. Ten cases were identified and scrutinized for viral inclusion bodies which were present in 5 of 10 cases. Two similar cases with interface dermatitis and viral inclusion bodies, which were not part of a retrospective search, were from the Oregon Veterinary Diagnostic Laboratory. The authors describe a total of 7 horses with dermatitis characterized by crusted, alopecic, non-pruritic, non-painful, irregular to annular areas over the face, most commonly the muzzle, for up to several years duration. Histologically, there was a CD3+ T lymphocyte-dominated lymphohistiocytic interface dermatitis with hydropic degeneration, apoptotic keratinocytes, and pigmentary incontinence. Keratinocytes within the upper stratum spinosum and stratum granulosum had glassy pale basophilic intranuclear inclusion bodies consistent with herpesvirus. The presence of EHV-5 was confirmed by quantitative polymerase chain reaction (qPCR) and in situ hybridization in 7 horses and by electron microscopy in 1 horse. One horse later developed EMPF and was euthanized. EHV-5 was not detected with qPCR from 5 control horses and 5 horses with interface dermatitis without histologic evidence of viral inclusion bodies. These are the first cases of facial interface dermatitis associated with EHV-5 reported in the United States. [ABSTRACT FROM AUTHOR]

Cutaneous manifestations of the 2019 coronavirus disease (COVID-19) are diverse and may be the only clinical evidence of infection, particularly in children [1]. The authors report a 10-year-old girl with erythematous vesicular papules and targetoid lesions of the extremities two weeks after polymerase chain reaction (PCR) confirmed severe acute respiratory syndrome coronavirus two (SARS-COV-2) infection. Biopsy depicted classic erythema multiforme (EM) and serology confirmed positive COVID-19 antibodies. This report demonstrates one of the first reported pediatric cases of typical clinical and histopathologic EM in relation to confirmed COVID-19.

Keratosis lichenoides chronica (KLC) or Nekam's disease, is an uncommon dermatosis, assumed for years as a variant of another inflammatory dermatosis (such as cutaneous lupus erythematosus or lichen planus) but currently accepted as a distinctive condition. Although pathophysiologic mechanisms need further research, clinical aspects of KLC are well-characterised, particularly lichenoid hyperkeratotic papules arranged linearly or in a reticulate pattern over the extremities, seborrheic-like dermatitis on the face and oral or genital erosions. Histopathology usually shows lichenoid interface dermatitis with numerous necrotic keratinocytes and parakeratosis. Keratosis lichenoides chronica (KLC) typically has a chronic progressive course with poor response to treatment. In the following case, we present a 56-year-old man with chronic dermatosis whose clinicopathological findings allowed the diagnosis of KLC. The patient was treated with acitretin, topical steroids and topical calcineurin inhibitors with partial improvement of the lesions. [ABSTRACT FROM AUTHOR]

Toxic erythema of chemotherapy (TEC) is an infrequently reported cutaneous condition, with diagnosis predominately based on clinical presentation, histologic findings, and known reported associations. Therefore, it is important to both recognize common presentations of TEC and be mindful of chemotherapeutic agents associated with this cutaneous side effect to prevent misdiagnosis and prolonged time to treatment. Herein, we present a patient with TEC occurring in intertriginous skin (malignant intertrigo) with classic clinical and histologic findings. In our patient this was associated with a combination neoadjuvant gemcitabine and paclitaxel therapy, a relationship that, to our knowledge, has yet to be reported in the literature.

Background: Extranodal NK/T cell lymphoma, nasal type (ENK/T) with cutaneous involvement has various histopathological findings and diverse clinical manifestations. Methods: A retrospective study of cutaneous involvement of ENK/T lymphoma between 2006 and 2018 was conducted. Results: Twenty-two cases were eligible for this study. Twelve cases could be proven as secondary cutaneous involvement by ENK/T lymphoma, while the remaining could not be confirmed as primary cutaneous ENK/T lymphoma. The histopathological patterns included dermal and subcutaneous nodular infiltration pattern in 11/22 cases (50%), lobular panniculitis pattern in 6/22 cases (27.3%), interface dermatitis pattern in 4/22 cases (18.2%), and granulomatous dermatitis pattern in 1/22 case (4.5%). The median follow-up was 18.3 months. Overall, the one-year and five-year survival rates were 31.3% and 13.3%, respectively. Conclusions: A variety of histopathological patterns of cutaneous involvement by ENK/T lymphoma should be differentiated from other cutaneous lymphomas, dermatitis, and infection. When atypical medium or large-sized lymphoid cells are encountered within skin lesions, pathologists should realize these lesions can be ENK/T lymphoma, especially in cases with coexisting tumor necrosis or angioinvasion. A complete evaluation of the upper aerodigestive tract is mandatory to identify the occult primary site of ENK/T lymphoma before establishing primary cutaneous ENK/T lymphoma.

Background: Histopathologic features of interface dermatitis can occasionally be seen in mycosis fungoides (MF), particularly in early patch-stage disease. Materials and Methods: We identified six patients with MF whose early biopsy specimens showed such prominent interface dermatitis that a benign diagnosis was favored. All subsequent specimens were reviewed for these patients, and the histopathologic evolution of disease was documented. Immunohistochemistry (IHC) for CD2, CD3, CD4, CD5, CD7, CD8, CD30, and CD123 was performed retrospectively. Educational archives were reviewed to assess the incidence of interface dermatitis in biopsies otherwise diagnostic of MF. Results: A spectrum of vacuolar and lichenoid patterns of interface change was observed in this series of six patients eventually diagnosed as having MF, and was seen as a recurring pattern in multiple specimens over time. In retrospect, findings described in early MF such as lining up of lymphocytes along the dermal--epidermal junction within the basal layer, papillary dermal fibrosis, and intraepidermal lymphocyte atypia could be appreciated to varying degrees in the confounding specimens. CD123 was negative in all cases, putatively excluding a connective tissue disease (CTD). None of the early biopsies showed loss of pan-T antigens CD2, CD5, and CD7. Forty-six of 164 cases (28%) of MF in an archival study set showed varying degrees of interface dermatitis in the setting of otherwise diagnostic changes of MF. Conclusions: Early MF can show prominent interface change and mimic inflammatory dermatoses. Histopathologic clues suggestive of MF should be carefully assessed, and IHC for CD123 may be helpful in distinguishing MF from CTD. Repeat biopsies over time may be necessary to arrive at a definitive diagnosis, in conjunction with ancillary studies and strong clinicopathologic correlation. [ABSTRACT FROM AUTHOR]

Lupus erythematosus is an autoimmune connective tissue disorder showing a broad spectrum of clinical manifestations.

Background: Early inflammatory lesions of lichen sclerosus are histopathologically difficult to diagnose until the hallmark of the disease i.e., papillary sclerosis becomes visible in histological sections. Pre-sclerotic and late or resolved phases of the disease have not been extensively studied. Methods: We retrospectively reviewed all cases diagnosed as genital lichen sclerosus over a ten-year period from 2006 to 2016, correlating the clinical findings with the histological features. Results: A total of 133 cases of genital lichen sclerosus (90 males and 43 females) were identified. Both genders demonstrated a similar histological spectrum. Fifty eight (44%) cases were identified as having pre-sclerotic lichen sclerosus, 64 (48%) as having progressive disease and 11 (8%) cases were classified as fully resolved with atrophy. Asymptomatic vitiligoid lesions were identified in 19 (14%) cases of which 12 were male. Low-grade squamous cell carcinoma was seen within the areas affected by long-standing lichen sclerosus, in four patients (3%, 2 male). Limitations: We studied only haematoxylin and eosin stained sections. The presence of basement membrane thickening could have been better illustrated with the periodic acid–Schiff stain. Conclusion: The pathogenesis of lichen sclerosus probably involves an immune reaction to the basement membrane at the epidermal interface and around the adnexa. The initial band of inflammation shifts gradually downwards from the epidermal interface into the dermis destroying the vascular channels and appendages, resulting in excessive deposition of altered extracellular matrix. Basilar infiltration of lymphocytes along with a grossly vacuolated or thickened basement membrane is proposed as the characteristic diagnostic feature of the pre-sclerotic stage. Greater awareness of the clinicopathological spectrum of lichen sclerosus should enable early diagnosis and treatment, thereby preventing structural damage and possible malignant transformation in chronic cases. [ABSTRACT FROM AUTHOR]

Apalutamide, an oral androgen receptor signaling inhibitor, is approved for the treatment of nonmetastatic castration-resistant prostate cancer and metastatic prostate cancer. In the international randomized placebo-controlled clinical trials, apalutamide was associated with a higher rate of rash than placebo. However, given that reports from a dermatological perspective are limited, the skin manifestations and histopathology of the skin lesions caused by apalutamide are largely unknown. Here, we report a case of apalutamide-induced drug eruption. A 66-year-old man developed itchy maculopapular erythema on the trunk and extremities 10 weeks after starting apalutamide for progressive prostate cancer. A biopsy specimen showed interface dermatitis with perivascular lymphocytic infiltration in the upper dermis. The lymphocyte transformation test was positive for apalutamide. The skin manifestations improved after discontinuation of apalutamide and treatment with topical corticosteroids and systemic prednisolone. A review of the dermatology literature on apalutamide-induced drug eruption yielded only six cases, including our case. Dermatologically, there were four cases of maculopapular rash and two of toxic epidermal necrolysis and histopathologically, there were three cases of interface dermatitis, two of epidermal necrosis, and one of spongiotic dermatitis. Four patients had peripheral eosinophilia. A lymphocyte transformation test was performed in three cases and was positive for apalutamide in all cases. Except for the two cases of toxic epidermal necrolysis, which were fatal, the skin eruptions appeared 10 weeks after starting apalutamide. Considering the increasing number of patients with prostate cancer being treated with apalutamide, cases of apalutamide-induced drug eruption need to be accumulated and analyzed. [ABSTRACT FROM AUTHOR]

Background: Extranodal NK/T cell lymphoma, nasal type (ENK/T) with cutaneous involvement has various histopathological findings and diverse clinical manifestations. Methods: A retrospective study of cutaneous involvement of ENK/T lymphoma between 2006 and 2018 was conducted. Results: Twenty-two cases were eligible for this study. Twelve cases could be proven as secondary cutaneous involvement by ENK/T lymphoma, while the remaining could not be confirmed as primary cutaneous ENK/T lymphoma. The histopathological patterns included dermal and subcutaneous nodular infiltration pattern in 11/22 cases (50%), lobular panniculitis pattern in 6/22 cases (27.3%), interface dermatitis pattern in 4/22 cases (18.2%), and granulomatous dermatitis pattern in 1/22 case (4.5%). The median follow-up was 18.3 months. Overall, the one-year and five-year survival rates were 31.3% and 13.3%, respectively. Conclusions: A variety of histopathological patterns of cutaneous involvement by ENK/T lymphoma should be differentiated from other cutaneous lymphomas, dermatitis, and infection. When atypical medium or large-sized lymphoid cells are encountered within skin lesions, pathologists should realize these lesions can be ENK/T lymphoma, especially in cases with coexisting tumor necrosis or angioinvasion. A complete evaluation of the upper aerodigestive tract is mandatory to identify the occult primary site of ENK/T lymphoma before establishing primary cutaneous ENK/T lymphoma. [ABSTRACT FROM AUTHOR]

Lichen striatus is a rare inflammatory dermatosis that follows the lines of Blaschko. This paper discusses an unusual presentation of lichen striatus following hepatitis B vaccination and reviews the literature of vaccine-induced lichen striatus.

Lichen planus follicularis tumidus (LPFT) is a rare subtype of lichen planus (LP) that has been most commonly described in middle-aged women. LPFT clinically manifests as recurrent cystic follicular nodules that preferentially involve the retroauricular area; concurrent classic LP lesions on the extremities and mucosal surfaces may also be present. Histologically, LPFT demonstrates epithelial-lined follicular cysts filled with orthokeratotic keratin surrounded by a dense lichenoid infiltrate. We present a case of a 67-year-old man with clinical and histopathologic findings consistent with LPFT and discuss differential diagnostic considerations for entities resembling LPFT. Lastly, treatment options for LPFT are reviewed.

Annular lichenoid dermatitis of youth is a rare chronic dermatosis with an unknown cause, affecting both genders at an equal frequency. It is clinically characterized by a hypopigmented center and an erythematous border or hyperpigmented annular patches or plaques. The differential diagnosis includes annular dermatoses, such as tinea, erythema annulare centrifugum, erythema chronicum migrans, morphea, and mycosis fungoides. In this case report, we examined the clinical and histopathological features of two male patients aged 9 and 12 years with annular lichenoid dermatitis and presented their 3-year follow-up data while also reviewing the cases reported in the literature.

(1) Background: Coronavirus disease 2019 (COVID-19) vaccines are currently employed on a population-wide scale in most countries worldwide. Data about unusual cutaneous adverse drug reactions (ADR) are scant, though. (2) Methods: We retrospectively analyzed moderate to severe vaccine-related ADR in the Department of Dermatology and Allergy of the University Hospital Bonn between May to June 2021 and analyzed related skin biopsies. (3) Results: As a specialized dermatological academic center, we encountered a total of n = 19 clinically and pathologically heterogeneous cutaneous ADR with a female predominance. Delayed cutaneous ADR occurred as late as 30 days after vaccination. The majority of ADR were mild, though a few patients required systemic treatment (antihistamines, glucocorticosteroids). (4) Conclusions: The clinico-pathological spectrum of cutaneous side effects with COVID-19 vaccines is wide; however, the benefits outweigh the risks by far. More dermatopathological studies on cutaneous ADR not limited to COVID-19 vaccines are desirable to enable a better understanding of underlying pathophysiological mechanisms.

The interface dermatitides encompass a vast array of cutaneous entities which, at times, may present with particular clinical variants with adnexal predilection. Similarly, hair follicle and eccrine gland involvement of some of these entities has been observed on histopathology. This review aims to describe the various adnexotropic presentations of the interface dermatitides. Recognizing that the adnexa can be a frequent site of involvement of these conditions may aid dermatopathologists in making the correct diagnosis and avoid misinterpreting adnexotropism for other conditions such as the great imitator, mycosis fungoides.

Copyright of ScienceRise: Medical Science is the property of PC TECHNOLOGY CENTER and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cutaneous lupus erythematosus (CLE) is an interferon (IFN)-driven autoimmune disease that may be limited to the skin or can be associated with systemic lupus erythematosus (SLE). CLE occurs in several morphologic subtypes ranging from isolated, disc-shaped plaques to disseminated skin lesions. The typical histopathologic pattern of skin lesions is named interface dermatitis and characterized by a lymphocytic infiltrate and necroptotic keratinocytes at the dermo-epidermal junction. Other histopathologic patterns primarily involve the dermis or subcutis, depending on the subtype. One critical mechanism in CLE is the chronic reactivation of innate and adaptive immune pathways. An important step in this process is the recognition of endogenous nucleic acids released from dying cells by various pattern recognition receptors (PRRs), including Toll-like receptors (TLRs) and other cytosolic receptors. Crucial cells in CLE pathogenesis comprise plasmacytoid dendritic cells (pDCs) as major producers of type I IFN, T cells exerting cytotoxic effects, and B cells, previously believed to contribute via secretion of autoantibodies. However, B cells are increasingly considered to have additional functions, supported by studies finding them to occur in highest numbers in chronic discoid lupus erythematosus (CDLE), a subtype in which autoantibodies are often absent. More precise knowledge of how CLE subtypes differ pathophysiologically may allow a tailored pharmacotherapy in the future, taking into account the specific molecular signature in relation to the morphologic subtype.

Cutaneous Lupus Erythematosus (CLE) is an autoimmune skin disease that occurs in almost two-thirds of people with Systemic Lupus Erythematosus (SLE) and can exist as its own entity. Despite its negative impact on the quality of life of patients, lupus pathogenesis is not fully understood. In recent years, the role of gene expression analysis has become important in understanding cellular functions and disease causation within and across species. Interestingly, dogs also develop CLE, providing a spontaneous animal model of disease. Here, we present a targeted transcriptomic analysis of skin biopsies from a case series of four dogs with complex autoimmunity with suspected CLE. We identified 92 differentially expressed genes (DEGs), including type 1 interferon, B cell, and T cell-related genes, in the four cases compared to healthy skin margin controls. Additionally, we compared our results with existing CLE datasets from humans and mice and found that humans and canines share 49 DEGs, whereas humans and mice shared only 25 DEGs in our gene set. Immunohistochemistry of IFNG and CXCL10, two of the most highly upregulated inflammatory mediators, confirmed protein-level expression and revealed immune cells as the primary source of CXCL10 in dogs with SLE, whereas keratinocytes stained strongly for CXCL10 in dogs without SLE. We propose that gene expression analysis may aid the diagnosis of complex autoimmune skin diseases and that dogs may provide important insights into CLE and SLE pathogeneses, or more broadly, skin manifestations during systemic autoimmunity.

(1) Background: Coronavirus disease 2019 (COVID-19) vaccines are currently employed on a population-wide scale in most countries worldwide. Data about unusual cutaneous adverse drug reactions (ADR) are scant, though. (2) Methods: We retrospectively analyzed moderate to severe vaccine-related ADR in the Department of Dermatology and Allergy of the University Hospital Bonn between May to June 2021 and analyzed related skin biopsies. (3) Results: As a specialized dermatological academic center, we encountered a total of n = 19 clinically and pathologically heterogeneous cutaneous ADR with a female predominance. Delayed cutaneous ADR occurred as late as 30 days after vaccination. The majority of ADR were mild, though a few patients required systemic treatment (antihistamines, glucocorticosteroids). (4) Conclusions: The clinico-pathological spectrum of cutaneous side effects with COVID-19 vaccines is wide; however, the benefits outweigh the risks by far. More dermatopathological studies on cutaneous ADR not limited to COVID-19 vaccines are desirable to enable a better understanding of underlying pathophysiological mechanisms. [ABSTRACT FROM AUTHOR]

Dysregulated skin immunity is a hallmark of many skin diseases such as atopic dermatitis, autoimmune blistering diseases, and interface dermatitis. Current treatment options for the inflammatory skin diseases are limited and sometimes ineffective, therefore further understanding of pathomechanisms in the inflammatory skin conditions is necessary to develop new therapeutic alternatives. Recent studies suggest that the serine protease, granzyme B, is a key mediator in multiple inflammatory skin diseases, implying that strategies targeting granzyme B may be an attractive treatment option for such diseases. Specifically, granzyme B exhibits not only an intracellular apoptotic function but also extracellular proteolytic roles in inflammatory skin diseases including infectious diseases, pemphigoid diseases, atopic dermatitis, alopecia areata, and interface dermatitis. In this review, we summarize the current understanding with respect to the functions of granzyme B in the pathomechanism of various inflammatory skin diseases and evaluate the possibility of therapeutics targeting granzyme B. • Granzyme B is a serine protease exhibiting both cytotoxic and extracellular roles. • Granzyme B is released not only from cytotoxic T cells and NK cells, but also from other immune and non-immune cells. • Granzyme B exhibits pathological roles in multiple inflammatory skin diseases. • Inhibition of granzyme B may be a treatment option for these inflammatory skin diseases. [ABSTRACT FROM AUTHOR]

Copyright of Turkderm - Turkish Archives of Dermatology & Venereology is the property of Galenos Yayinevi Tic. LTD. STI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The interface dermatitides encompass a vast array of cutaneous entities which, at times, may present with particular clinical variants with adnexal predilection. Similarly, hair follicle and eccrine gland involvement of some of these entities has been observed on histopathology. This review aims to describe the various adnexotropic presentations of the interface dermatitides. Recognizing that the adnexa can be a frequent site of involvement of these conditions may aid dermatopathologists in making the correct diagnosis and avoid misinterpreting adnexotropism for other conditions such as the great imitator, mycosis fungoides. [ABSTRACT FROM AUTHOR]

Background: Dermatomyositis (DM) is conventionally characterized by interface dermatitis (ID) on skin histopathology. A subset of DM patients has skin biopsies showing spongiotic dermatitis (SD), a histopathology more commonly seen in eczema. In this study, we aimed to (a) identify the percentage of clinically diagnosed DM patients with SD skin biopsies, (b) identify cytokine and cell markers that can help determine if a SD skin biopsy is consistent with DM. Methods: In this case‐control study, biopsy specimens from ten DM patients with SD (DM‐SD) were compared to specimens from ten healthy controls, ten patients with eczema, and 12 patients with DM with ID (DM‐ID). Specimens were stained by immunohistochemistry for MxA, IFN‐β, CD11c, and BDCA2. One‐way ANOVA with Bonferroni's multiple comparison test was used to compare protein expression between groups. Results: Eleven of 164 (6.7%) patients with a clinical diagnosis of DM at our tertiary care center were identified as having SD. MxA, IFN‐β, CD11c, and BDCA2 protein expression was significantly higher in DM‐SD compared to eczema and healthy controls. Expressions of MxA, IFN‐β, and BDCA2 were not significantly different between DM‐SD and DM‐ID. Conclusion: Increased MxA, IFN‐β, CD11c, and BDCA2 protein expression may aid in distinguishing between DM‐SD and eczema and warrants further investigation. [ABSTRACT FROM AUTHOR]

Abstract is missing (Short communication)

Cutaneous Lupus Erythematosus (CLE) is a clinically diverse group of autoimmune skin diseases with shared histological features of interface dermatitis and autoantibodies deposited at the dermal–epidermal junction. Various genetic and environmental triggers of CLE promote infiltration of T cells, B cells, neutrophils, antigen presenting cells, and NK cells into lesional skin. In this mini-review, we will discuss the clinical features of CLE, insights into CLE immunopathogenesis, and novel treatment approaches.

Abstract We report a case of noninfectious vacuolar interface dermatitis associated with colonic and perianal ulceration in a patient with acquired immunodeficiency syndrome (AIDS), which responded to immunosuppressive treatment. Our findings suggest that interface dermatitis in the setting of AIDS may warrant further gastrointestinal evaluation and may respond to immunosuppression.

Background: There are conflicting reports on the association between interface dermatitis and hepatic involvement in DRESS. Methods: A cross‐sectional analysis of the clinical and the histopathologic features of DRESS was performed to study the association between the histopathology of the skin rash and hepatic involvement. Results: The clinical and the histopathologic findings were evaluated in 40 cases of DRESS. Thirty patients (75%) had a hepatic involvement. Thirty (75%) biopsy specimens showed a combination of different inflammatory patterns. The interface dermatitis was noted in 24 specimens (60%). Twenty‐one patients with the interface dermatitis had a hepatic involvement (P =.04). Conclusions: The skin rash of DRESS often shows the coexistence of different inflammatory patterns. The interface dermatitis showed a statistically significant association with the hepatic involvement in DRESS. [ABSTRACT FROM AUTHOR]

Discrete junctional cellular aggregates ("nests"), partially staining with melanocytic markers, are described in lichenoid tissue reaction, mainly from chronically sun‐exposed skin. The concomitant epidermal flattening and papillary dermal fibrosis with melanophages, may raise the differential diagnosis to that of a regressing melanoma. We describe three cases of interface dermatitis of the head/neck area with clinicopathological features of melanotic discoid lupus erythematosus. These cases showed junctional aggregates, a few composed of inflammatory cells and colloid bodies ("pseudomelanocytic nests"), while others composed of S100‐ but MART‐1+, MITF+, and SOX‐10+ cells ("true melanocytic nests"); negativity of the melanocytic component for PRAME was a clue to benignity. True junctional melanocytic nesting may be induced by lichenoid dermatoses on chronically sun‐damaged skin. The presence of colloid bodies and of the double negativity for S100 (within nests) and PRAME (both within nests and single melanocytes), together with clinicopathological correlation, avoids misdiagnosis. [ABSTRACT FROM AUTHOR]

Lichen planus is an idiopathic inflammatory dermatological condition affecting skin and mucosa. Certain variants of lichen planus may present a difficulty in diagnosis especially when the lesions are arranged in linear or blaschkoid pattern. Correct diagnosis and treatment of this condition are necessary to prevent any undue investigation and for cosmetic appearance. We herein report case series of 3 patients with unilateral blaschkoid lichen planus. [ABSTRACT FROM AUTHOR]

Cutaneous Lupus Erythematosus (CLE) is a clinically diverse group of autoimmune skin diseases with shared histological features of interface dermatitis and autoantibodies deposited at the dermal–epidermal junction. Various genetic and environmental triggers of CLE promote infiltration of T cells, B cells, neutrophils, antigen presenting cells, and NK cells into lesional skin. In this mini-review, we will discuss the clinical features of CLE, insights into CLE immunopathogenesis, and novel treatment approaches. [ABSTRACT FROM AUTHOR]

Keywords: allergic contact dermatitis; case report; cicatricial alopecia; color shampoo; hair dye; hyperpigmentation; interface dermatitis; lichenoid reaction; paraphenylenediamine; patch test EN allergic contact dermatitis case report cicatricial alopecia color shampoo hair dye hyperpigmentation interface dermatitis lichenoid reaction paraphenylenediamine patch test 59 61 3 12/17/21 20220101 NES 220101 Allergic reactions to hair dye are common and may vary from mild localized pigmentation to severe dermatitis and rarely systemic complications. We here report an unusual case of cicatricial alopecia following severe allergic contact dermatitis from paraphenylenediamine (PPD) in hair dyes. [Extracted from the article]

Copyright of Der Hautarzt is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Cutaneous warts have high prevalence and cause significant morbidity. Understanding the mechanisms by which warts evade the immune system could lead to targeted and improved treatments.Objective: To determine whether cutaneous warts express programmed cell death ligand 1 (PD-L1) and to characterize the expression of programmed cell death 1 (PD-1) within the immune infiltrate of inflamed lesions.Methods: In total, 44 biopsies of cutaneous warts were retrieved from the Department of Dermatopathology archives of the University of California, San Francisco. Biopsies were stained with hematoxylin and eosin and PD-L1 monoclonal antibody, and biopsies of inflamed lesions were stained with PD-1 monoclonal antibody.Results: PD-L1 was expressed on keratinocytes in cases of verrucae vulgares (12/30, 40%) and myrmecia (7/14, 50%) and was associated with an interface inflammatory reaction. PD-1 was expressed by the inflammatory infiltrate in verrucae vulgares (21/24, 88%) and myrmecia (5/8, 63%).Limitations: This was a retrospective observational study conducted at a single institution.Conclusion: Many cutaneous warts express PD-L1, suggesting that human papillomavirus might use this pathway to promote immune dysfunction. This discovery helps explain the recalcitrance of warts to current therapies and provides a rationale for investigating anti-PD-1 immunotherapy as a potential treatment for warts. [ABSTRACT FROM AUTHOR]

Autoimmune diseases are devastating conditions in which the immune system is directed against the host, leading to life-threatening destruction of organs. Although autoantigens are ill-defined in most autoimmune diseases, this is not the case in the skin. Autoimmune bullous diseases have been extensively studied with detailed characterization of autoantigens, the epitopes that are targeted, and the mechanisms of action that mediate autoimmune tissue destruction. Pemphigus is an autoimmune bullous disease caused by circulating IgG that targets two desmosomal proteins, desmoglein 1 and 3, which are crucial for cell–cell adhesion of keratinocytes. Binding of auto-antibodies to desmogleins impairs keratinocyte adhesion, leading to severe blistering disease. Mouse models that recapitulate the human disease have been instrumental in elucidating the detailed pathophysiology. Taking advantage of the fact that desmogleins are specifically targeted in pemphigus, studying humoral and cellular autoimmunity against these autoantigens provides us with an opportunity to understand not only the effector mechanisms of B and T cells in mediating pathology but also how autoreactive lymphocytes are regulated during development in the thymus and post-development in the periphery. This review introduces pemphigus and its subtypes as prototypic autoimmune diseases from which recent basic and translational developments should provide insight into how autoimmunity develops. [ABSTRACT FROM AUTHOR]

Background: Common histopathologic findings in cutaneous dermatomyositis include vacuolar interface with dyskeratosis, mucin, and perivascular inflammation. Data examining the relationships between these and other histologic abnormalities, or their dependence on biopsy site, and medications are limited. Methods: Using 228 dermatomyositis skin biopsies and statistical analyses including Chi‐squared analyses, calculations of relative risk, and adjusted generalized estimating equation regressions, we investigated relationships between 14 histopathologic findings and the impact of clinical factors on these findings. Results: In biopsies taken from sites of visible rash, interface dermatitis was seen in 91%, and 95% had at least one of perivascular inflammation, mucin, or basal vacuolization. Vascular abnormalities were not closely associated with epidermal or inflammatory findings. Concomitant prednisone significantly decreased the odds of basal vacuolization (odds ratio [OR] = 0.34, 95% confidence interval [CI]: 0.12‐0.98, P‐value = 0.05), perivascular inflammation (OR = 0.19, 95% CI: 0.07‐0.53, P‐value = 0.002), and vessel damage (OR = 0.81, 95% CI: 0.68‐0.96, P‐value = 0.02). Conclusion: Vasculopathy and classic findings of interface dermatitis may be driven by unique pathways in dermatomyositis. Corticosteroid use may impact skin biopsy findings. There is a need for clinicopathologic correlation when diagnosing dermatomyositis. [ABSTRACT FROM AUTHOR]