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Many patients with chronic wounds have skin changes that can provide important clues as to the etiology of the wound and/or inappropriate treatment. As the largest human organ, the skin is easily accessible for clinical inspection. However, healthcare professional teams currently do not always assess and document these skin changes correctly and consistently. The board of the professional society Initiative Chronische Wunden (ICW) e. V. has therefore decided to draw up a position paper to clarify the most important technical terms for skin changes around wounds. One focus here is on the definition and differentiated description of the wound edge and wound surrounding skin. Atrophies, blisters, eczema, erythema, hemorrhages, hyperpigmentation, hypopigmentation, hyperkeratosis, maceration, necrosis, oedema, pustules, sclerosis and scales are then described in more detail and placed in a clinical context., Competing Interests: Die Autorinnen/Autoren geben an, dass kein Interessenkonflikt besteht., (Thieme. All rights reserved.)

Cutaneous imaging is a central tenant to the practice of dermatology. In this article, the authors explore various noninvasive and invasive skin imaging techniques, as well as the latest deployment of these technologies in conjunction with the use artificial intelligence and machine learning. The authors also provide insight into the benefits, limitations, and challenges around integrating these technologies into dermatologic practice., Competing Interests: Disclosure Dr Y.R. Semenov is an advisory board member/consultant and has received honoraria from Incyte Corporation, Castle Biosciences, Galderma, and Sanofi outside of the submitted work. Dr Y.R. Semenov is supported in part by the Melanoma Research Alliance Young Investigator Award., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Macular amyloidosis (MA) is a primary localized cutaneous amyloidosis, characterized by amyloid deposition in the papillary dermis. The clinical presentation includes pruritic hyperpigmented macules and patches with a reticulated or rippled pattern, primarily found on the upper back and extremities. Biopsy is an essential diagnostic tool for confirming MA. This systematic review focused on the biopsy outcomes in patients diagnosed with MA., (© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Acute skin failure (ASF) is an inevitable damage to the skin and subcutaneous tissue caused by hemodynamic instability and/or low perfusion. At present, there are some understandings and reports about adult ASF at home and abroad, but there are few reports about children's ASF. This article reviewed the definition, pathophysiological changes, risk factors, clinical manifestations, and management of children's ASF, and put forward suggestions in order to provide ideas for clinical diagnosis and treatment of children's ASF, and promote the further study of children's ASF.

This manuscript reviews the significant skin manifestations of Lewy body disease, including Parkinson's disease and dementia with Lewy bodies, and the diagnostic utility of skin biopsy. Besides classic motor and cognitive symptoms, non-motor manifestations, particularly dermatologic disorders, can play a crucial role in disease presentation and diagnosis. This review explores the intricate relationship between the skin and Lewy body disease. Seborrheic dermatitis, autoimmune blistering diseases (bullous pemphigoid and pemphigus), rosacea, and melanoma are scrutinized for their unique associations with Parkinson's disease, revealing potential links through shared pathophysiological mechanisms. Advances in diagnostic techniques allow the identification of promising biomarkers such as α-synuclein in samples obtained by skin punch biopsy. Understanding the dermatologic aspects of Lewy body disease not only contributes to its holistic characterization but also holds implications for innovative diagnostic approaches.

In this chapter, we provide detailed instructions to perform quantitative reflectance imaging in a mouse model of a rare epidermal disorder caused by hyperactive connexin 26 hemichannels. Reflectance imaging is a versatile and powerful tool in dermatology, offering noninvasive, high-resolution insights into skin pathology, which is essential for both clinical practice and research. This approach offers several advantages and applications. Unlike traditional biopsy, reflectance imaging is noninvasive, allowing for real-time, in vivo examination of the skin. This is particularly valuable for monitoring chronic conditions or assessing the efficacy of treatments over time, enabling the detailed examination of skin morphology. This is crucial for identifying features of skin diseases such as cancers, inflammatory conditions, and infections. In therapeutic applications, reflectance imaging can be used to monitor the response of skin lesions to treatments. It can help in identifying the most representative area of a lesion for biopsy, thereby increasing the diagnostic accuracy. Reflectance imaging can also be used to diagnose and monitor inflammatory skin diseases, like psoriasis and eczema, by visualizing changes in skin structure and cellular infiltration. As the technology becomes more accessible, it has potential in telemedicine, allowing for remote diagnosis and monitoring of skin conditions. In academic settings, reflectance imaging can be a powerful research tool, enabling the study of skin pathology and the effects of novel treatments, including the development of monoclonal antibodies for therapeutic applications., (© 2024. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Over 1000 heritable disorders have cutaneous manifestations, some of which are syndromicin association with extracutaneous manifestations, whereas others are limited to the skin. The genetic basis of many of these conditions has been deciphered, and mutation analyses using next-generation sequencing approaches, including whole-exome sequencing, whole-genome sequencing, and whole-transcriptome analysis, are now increasingly becoming part of the diagnostic process. Besides confirming the diagnosis, information on the specific mutations can be used for subclassification with prognostication and identification of the carriers, leading to accurate genetic counseling. It also forms a basis for prenatal testing and preimplantation genetic diagnosis. Furthermore, the ongoing therapeutics developments for heritable skin diseases are often allele-specific, necessitating the knowledge of the specific genes and mutations. Although practicing clinicians increasingly employ molecular diagnostics for heritable skin diseases, they often lack the sufficient knowledge required to interpret the implications of the mutations with precision. The purpose of this primer is to provide an overview of mutation-detection strategies and how to interpret genetic information for improved diagnostics and the management of such patients., Competing Interests: Conflicts of interest None disclosed., (Copyright © 2021 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.)

Accurate skin lesion diagnosis requires a great effort from experts to identify the characteristics from clinical and dermoscopic images. Deep multimodal learning-based methods can reduce intra- and inter-reader variability and improve diagnostic accuracy compared to the single modality-based methods. This study develops a novel method, named adversarial multimodal fusion with attention mechanism (AMFAM), to perform multimodal skin lesion classification. Specifically, we adopt a discriminator that uses adversarial learning to enforce the feature extractor to learn the correlated information explicitly. Moreover, we design an attention-based reconstruction strategy to encourage the feature extractor to concentrate on learning the features of the lesion area, thus, enhancing the feature vector from each modality with more discriminative information. Unlike existing multimodal-based approaches, which only focus on learning complementary features from dermoscopic and clinical images, our method considers both correlated and complementary information of the two modalities for multimodal fusion. To verify the effectiveness of our method, we conduct comprehensive experiments on a publicly available multimodal and multi-task skin lesion classification dataset: 7-point criteria evaluation database. The experimental results demonstrate that our proposed method outperforms the current state-of-the-art methods and improves the average AUC score by above 2% on the test set., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

With the development of artificial intelligence, technique improvement of the classification of skin disease is addressed. However, few study concerned on the current classification system of International Classification of Diseases, Tenth Revision (ICD)-10 on Diseases of the skin and subcutaneous tissue, which is now globally used for classification of skin disease. This study was aimed to develop a new taxonomy of skin disease based on cytology and pathology, and test its predictive effect on skin disease compared to ICD-10. A new taxonomy (Taxonomy 2) containing 6 levels (Project 2-4) was developed based on skin cytology and pathology, and represents individual diseases arranged in a tree structure with three root nodes representing: (1) Keratinogenic diseases, (2) Melanogenic diseases, and (3) Diseases related to non-keratinocytes and non-melanocytes. The predictive effects of the new taxonomy including accuracy, precision, recall, F1, and Kappa were compared with those of ICD-10 on Diseases of the skin and subcutaneous tissue (Taxonomy 1, Project 1) by Deep Residual Learning method. For each project, 2/3 of the images were included as training group, and the rest 1/3 of the images acted as test group according to the category (class) as the stratification variable. Both train and test groups in the Projects (2 and 3) from Taxonomy 2 had higher F1 and Kappa scores without statistical significance on the prediction of skin disease than the corresponding groups in the Project 1 from Taxonomy 1, however both train and test groups in Project 4 had a statistically significantly higher F1-score than the corresponding groups in Project 1 (P = 0.025 and 0.005, respectively). The results showed that the new taxonomy developed based on cytology and pathology has an overall better performance on predictive effect of skin disease than the ICD-10 on Diseases of the skin and subcutaneous tissue. The level 5 (Project 4) of Taxonomy 2 is better on extension to unknown data of diagnosis system assisted by AI compared to current used classification system from ICD-10, and may have the potential application value in clinic of dermatology.

The SARS-CoV-2 pandemic has dramatically changed our lives and habits. In just a few months, the most advanced and efficient health systems in the world have been overwhelmed by an infectious disease that has caused 3.26 million deaths and more than 156 million cases worldwide. Although the lung is the most frequently affected organ, the skin has also resulted in being a target body district, so much so as to suggest it may be a real "sentinel" of COVID-19 disease. Here we present 17 cases of skin manifestations studied and analyzed in recent months in our Department; immunohistochemical investigations were carried out on samples for the S1 spike-protein of SARS-CoV-2, as well as electron microscopy investigations showing evidence of virions within the constituent cells of the eccrine sweat glands and the endothelium of small blood vessels. Finally, we conduct a brief review of the COVID-related skin manifestations, confirmed by immunohistochemistry and/or electron microscopy, described in the literature.

Precise measurement of particulate matter (PM) on skin is important for managing and preventing PM-related skin diseases. This study aims to directly visualize the deposition and penetration of PM into human skin using a multimodal nonlinear optical (MNLO) imaging system. We successfully obtained PM particle signals by merging two different sources, C-C vibrational frequency and autofluorescence, while simultaneously visualizing the anatomical features of the skin via keratin, collagen, and elastin. As a result, we found morphologically dependent PM deposition, as well as increased deposition following disruption of the skin barrier via tape-stripping. Furthermore, PM penetrated more and deeper into the skin with an increase in the number of tape-strippings, causing a significant increase in the secretion of pro-inflammatory cytokines. Our results suggest that MNLO imaging could be a useful technique for visualizing and quantifying the spatial distribution of PM in ex vivo human skin tissues.

Our skin is the interface between us and our environment - a flexible barrier that has evolved for protection, immunity, regulation and sensation. Once regarded as inert, we now know that it is a dynamic environment. Skin lipids are crucial to the structure and function of skin. From deep in the hypodermis, through the ceramide-rich epidermis, to the lipids of the skin surface, there are a vast array of different lipids with important roles to play. This review firstly discusses the lipid composition of human skin and secondly, changes that have been found in skin lipid composition in different skin diseases. Further research into skin lipids facilitated by ever-improving methodologies will no doubt generate new knowledge, paving the way for diagnosis, prevention and treatment of skin disorders and diseases., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Traditional immunohistochemistry (IHC) is inherently limited by its ability to analyze only several markers within a histological tissue section at a given time, which hinders in-depth characterization and phenotyping of tissues. Imaging mass cytometry (IMC), which combines IHC using metal-labeled antibodies with laser ablation and detection using mass cytometry by time-of-flight, overcomes this limitation with the capability to simultaneously analyze up to 40 protein markers to generate high-dimensional images from a single tissue section. IMC analysis preserves tissue architecture and spatial cellular relationships that would otherwise be lost or significantly altered in applications requiring tissue dissociation, such as flow cytometry or single-cell RNA sequencing. Resulting high-dimensional histological images permit spatially conserved analysis to identify unique cell populations, cellular interactions and avoidances, and insight into activation and behavioral status based on tissue location. IMC can be performed on both frozen and formalin-fixed paraffin-embedded tissue, allowing for previously banked samples to be analyzed and correlated with known clinical outcomes. Expectedly, IMC will change the landscape of investigative pathology, particularly when used in coordination with multiomic platforms to combine transcriptomic and proteomic data at a single-cell resolution. Here, we aim to highlight the potential utility of IMC within dermatologic research and clinical applications., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Technological advances in flow cytometry and the development of mass cytometry by time-of-flight (CyTOF) have led to progressive increases in the number of proteins and biochemical processes that can be simultaneously measured. The most recent development of these platforms, imaging mass cytometry (IMC), allows for the visualization of up to 40 unique cellular markers and also employs rare metal isotopes conjugated to antibodies. However, IMC also adds the important benefit of preserving two-dimensional (2D) tissue architecture; this is accomplished by staining in situ and direct tissue vaporization followed by generation of a 2D spectral reconstruction using CyTOF-captured events. We review the experimental methodology for IMC that enables high-resolution multilayer images depicting protein expression, cellular localization, and interaction in situ in dermatology research., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Importance: This is the first study to review the incidence of nasal skin compromise after open rhinoplasty surgery and outcomes of treatment. Objectives: To determine whether risk of skin compromise after open rhinoplasty surgery can be predicted and whether our treatment protocol led to acceptable outcomes. Design, Setting, and Participants: This is a retrospective chart review of the senior author's private patients. In total, 384 rhinoplasty cases were reviewed and all cases with signs of vascular compromise requiring treatment were analyzed. Main Outcomes and Measures: Descriptive statistics were used to evaluate characteristics of patients who developed intra- and postoperative skin compromise, and unpaired two-tailed t -test was used to compare the characteristics of patients with and without compromised nasal skin when possible. Overall satisfaction results and complications in the skin compromise group were reported. Results: A total of 384 open rhinoplasties were performed by the senior author between October 1, 2015, and December 31, 2018. Of them, 109 were primary rhinoplasties and 275 were revision rhinoplasties. Of the 384 rhinoplasties, 27 (7%) had skin compromise leading to unplanned postoperative treatment. Two of the patients in the skin compromise group underwent primary surgeries (7.4%) and 25 underwent revision procedures (92.6%). Advanced age ( p  < 0.0001), prior or current history of smoking ( p  = 0.027), and greater number of prior rhinoplasty surgeries ( p  = 0.0002) were significantly correlated with risk of skin compromise. The average time to last follow-up in the skin compromise group was 392 days (range 15-1057 days). At their last follow-up, 12 patients had complete resolution of all signs of nasal skin compromise with no further treatment required (44.4%). The revision rate for patients experiencing skin compromise was 22.2%. One patient underwent revision surgery directly related to a complication of skin compromise and one is considering revision directly related to skin breakdown. Conclusions and Relevance: The rate of skin compromise after open rhinoplasty is low. Older patients and patients with more prior rhinoplasty surgeries may be at increased risk. Prompt treatment of compromised nasal blood supply after rhinoplasty surgery can salvage skin in most patients.

The skin is the primary interface between the body and the environment. It is exposed to a variety of external physical factors to which it must respond in a dynamic manner. In the following review such cutaneous reactions to physical damage are discussed under the aspects of rheumatological differential diagnoses. In particular, circumscribed hyperpigmentation and hyperkeratosis, reactive patterns to cold, with or without humidity, and lightning are presented. Most of these disorders do not need extensive laboratory investigations or imaging techniques. Knowledge of such cutaneous disease symptoms due to physical damage prevents overdiagnostics and possible overtreatment.

Access to health information online has resulted in increased internet use to !nd medical education resources.1,2 The United States (US) population is comprised of 60.1% Whites, 18.5% Hispanics or Latinos, 13.4% Blacks or African Americans, with trends toward increasing diversity. Our objectives were to analyze skin color distributions on the American Academy of Dermatology (AAD) public education website.

We report a rare case of Wells syndrome in which a 61-year-old Caucasian male presented with three distinct skin lesions including a cutaneous bulla, an erythematous plaque, and a linear streak located on the patient's left anterior thigh, left dorsal wrist, and left anterior forearm, respectively. Histologic examination revealed diffuse and interstitial eosinophilic infiltrate admixed with lymphocytes and macrophages that predominantly involve the dermis. Nodular aggregates of eosinophils surrounding dermal collagen fibers suggestive of 'flame figures' were identified. Luna histochemical stain was used and highlighted the deposition of eosinophilic granules over the collagen bundles confirming the presence of flame figures. Laboratory workup revealed peripheral eosinophilia, but a comprehensive clinical evaluation failed to reveal a systemic disease and ultimately the diagnosis of eosinophilic cellulitis 'Wells Syndrome' was rendered. After a short course of immunosuppressive therapy, the patient experienced a complete resolution of the skin lesions on his last follow-up visit several weeks from the initial diagnosis. This case highlights the various clinical forms that Wells syndrome may present with and may serve as a good example for the use of Luna stain as a simple and cost-effective diagnostic tool that can help to arrive at the accurate diagnosis and inform therapy.

Skin conditions are one of the most common chief complaints encountered in the primary care setting. Primary care providers (PCPs) may not have not received enough exposure and education on dermatologic conditions. Of all skin conditions, atopic dermatitis, acne vulgaris, cellulitis/abscess, verruca vulgaris, and benign skin lesions are typically the most common to present in the primary care setting. PCPs must be well educated on these topics and confident in their diagnostic and management skills. This article reviews the five most common skin conditions encountered in primary care so that PCPs can reduce the number of referrals to dermatology for conditions that can easily be managed by PCPs.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the cause of the COVID-19 global pandemic, is notable for an expanding list of atypical manifestations including but not limited to coagulopathies, renal dysfunction, cardiac injury and a multisystem inflammatory syndrome in children. In addition, SARS-CoV-2 has been purportedly linked to multiple cutaneous manifestations, among them chilblain-like skin lesions, also known as "COVID toes." Driven in large part by social media, dermatologists around the world reported a dramatic increase in the frequency of chilblain-like diagnoses early in the COVID-19 pandemic, often in members of the same family. This phenomenon has been captured in a rapidly expanding medical literature. As of this writing, the chilblain-like presentation has been reported to occur predominantly in younger, minimally symptomatic patients and to emerge late in the COVID-19 disease course. Evidence of SARS-CoV-2 infection is not consistently found when these patients are evaluated by polymerase chain reaction. A robust antiviral immune response in young patients that induces microangiopathic changes has been posited as a mechanism. Herein we review the rapid evolution of the literature regarding chilblain-like skin lesions early in the COVID-19 global pandemic., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The initial clinical manifestations of COVID 19 in Wuhan was fever, cough and shortness of breath but early reports in Italy and Spain preceded emerging literature of skin involvement. COVID19 was first reported in December, 2019 and after several observations of cutaneous involvement in patients with the disease there was need to document such in literature. The details of the clinical presentation and the pathophysiological mechanisms of these cutaneous lesions are, however, still poorly understood. This is a review of twenty-four published scientific articles summarizing the various cutaneous features observed by the frontline health care givers involved in the management of patients with Covid-19. Maculopapular exanthem was the most common pattern reported, accounting for 44.4% of skin manifestations. The pseudo-chilblain, urticarial, vesicular, livedoid and Kawasaki-like disease patterns accounted for 18.1%, 17.6%, 12.9%, 5.1% and 1.9% respectively. Anumber of the patients (9.5%) developed skin lesions at the time of diagnosis of Covid-19 or at the onset of Covid-19 respiratory symptoms while 75.1% developed the lesions after the onset of Covid-19 respiratory symptoms or after laboratory diagnosis of the disease had been made. There is no gainsaying that apart from the respiratory and other reported systems, Covid-19 also affects the skin. Clinicians, especially dermatologists, should therefore watch out for the already reported skin lesions and for possible yet to be discovered or reported skin lesions in patients with Covid-19. Dermatologists must bear in mind that patients presenting at skin clinics may actually be infected with Covid-19.

Background: During the coronavirus disease 2019 pandemic, several acral chilblain-like lesions were observed in young patients with suspected, but mostly unconfirmed, infection with severe acute respiratory syndrome coronavirus 2. The histopathologic aspect of these lesions is as yet poorly known., Objective: To investigate the pathologic features of chilblain-like lesions., Methods: Biopsies were obtained from 17 cases of chilblain-like lesions during the coronavirus disease 2019 pandemic in France and were studied by routine histologic examination, immunohistochemistry, and direct immunofluorescence. The patients had suspected but unconfirmed infection with severe acute respiratory syndrome coronavirus 2 (negative nasopharyngeal polymerase chain reaction and serologic test results)., Results: Chilblain-like lesions showed many features in common with those reported in idiopathic and autoimmune-related chilblains, including epidermal necrotic keratinocytes, dermal edema, perivascular and perieccrine sweat gland lymphocytic (predominantly CD3/CD4 + ) inflammation, and frequent vascular changes (endothelialitis, microthromboses, fibrin deposition, and immunoreactant deposits on vessels)., Conclusions: Chilblain-like lesions show histopathologic features similar to those of idiopathic and autoimmune-related chilblains, with a high rate of vascular changes and direct immunofluorescence positivity. The role of severe acute respiratory syndrome coronavirus 2 in the development of these puzzling lesions remains to be elucidated., (Copyright © 2020 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.)

The novel coronavirus disease of 2019 (COVID-19) is associated with significant morbidity and mortality. While much of the focus has been on the cardiac and pulmonary complications, there are several important dermatologic components that clinicians must be aware of., Objective: This brief report summarizes the dermatologic manifestations and complications associated with COVID-19 with an emphasis on Emergency Medicine clinicians., Discussion: Dermatologic manifestations of COVID-19 are increasingly recognized within the literature. The primary etiologies include vasculitis versus direct viral involvement. There are several types of skin findings described in association with COVID-19. These include maculopapular rashes, urticaria, vesicles, petechiae, purpura, chilblains, livedo racemosa, and distal limb ischemia. While most of these dermatologic findings are self-resolving, they can help increase one's suspicion for COVID-19., Conclusion: It is important to be aware of the dermatologic manifestations and complications of COVID-19. Knowledge of the components is important to help identify potential COVID-19 patients and properly treat complications., Competing Interests: Declaration of competing interest None., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Localized deposition of mucin in the upper dermis is referred to as cutaneous focal mucinosis. Patients with this condition either present with a single skin lesion (solitary cutaneous focal mucinosis) or numerous skin lesions (multiple cutaneous focal mucinosis). A man with solitary cutaneous focal mucinosis is described and the features of this condition are reviewed. Solitary cutaneous focal mucinosis has a slight male predominance and typically presents in adults, ranging in age from 29 years to 60 years, as a nodule or papule that is flesh-colored or white and most commonly located on an extremity or the trunk. Microscopic examination shows deposition of mucin in the upper dermis; the overlying epidermis can be normal, atrophic or hyperplastic. The skin lesion is often removed at the time of biopsy. However, recurrence has not been observed when the mucin deposition is present at the edge of the biopsy or excision specimen. Although the pathogenesis of this condition remains to be established, in contrast to individuals with multiple cutaneous focal mucinosis, solitary cutaneous focal mucinosis is a unique primary cutaneous mucinosis unrelated to mucinosis-associated systemic diseases.

Objectives: Multicentric reticulohistiocytosis (MRH), a rare histiocytic disease that can mimic other rheumatic conditions, may be associated with cancer and other autoimmune disorders. To better understand the disorder and its other associations, we aimed to evaluate clinical correlates and outcomes of all patients with MRH seen at Mayo Clinic, Rochester between 1980 and 2017., Methods: A retrospective medical record review was conducted to identify all patients with MRH between 1 January 1980 and 30 April 2017., Results: We identified 24 patients with biopsy-proven MRH (58% female, 75% Caucasian, median age at diagnosis 52 years, median follow-up of 2.3 years). All patients had cutaneous and articular involvement; 23 (96%) patients had papulonodular skin lesions (87% periungual and dorsal hand) and seven (30%) mucosal nodules; and 22 (92%) patients had arthralgias, 21 (88%) joint effusions and 13 (54%) synovitis. Most frequently used therapies included corticosteroids, cyclophosphamide, methotrexate and bisphosphonates. Biologics were used in four patients. Nine patients had symptomatic resolution at 1 year and 12 partial improvement. Radiological findings included erosive changes in three (60%) patients and arthritis mutilans in two patients (40%). Twenty-nine per cent of patients had a concomitant autoimmune disease and 25% malignancy including melanoma, endometrial, peritoneal and lung carcinoma. The 5-year survival rate was 85% (95% CI: 74, 100%)., Conclusion: To our knowledge, this is the largest single-centre series of patients with MRH highlighting the rarity of the condition and an unmet need for treatment options that can allow sustained disease remission. It also highlights the need for a high vigilance for malignancy and autoimmune diseases., (© The Author(s) 2019. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Artificial intelligence is becoming increasingly important in dermatology, with studies reporting accuracy matching or exceeding dermatologists for the diagnosis of skin lesions from clinical and dermoscopic images. However, real-world clinical validation is currently lacking. We review dermatological applications of deep learning, the leading artificial intelligence technology for image analysis, and discuss its current capabilities, potential failure modes, and challenges surrounding performance assessment and interpretability. We address the following three primary applications: (i) teledermatology, including triage for referral to dermatologists; (ii) augmenting clinical assessment during face-to-face visits; and (iii) dermatopathology. We discuss equity and ethical issues related to future clinical adoption and recommend specific standardization of metrics for reporting model performance., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

We aim to evaluate the change in the diagnostic spectrum in dermatology outpatient applications compared to before COVID-19. All patients were enrolled from the Department of Dermatology between February 12 and May 8, 2020, the duration of 4 weeks before COVID-19 and 8 weeks after were analyzed in three parts consisting of 4 weeks. Data obtained from the database such as age, gender, diagnoses were anonymized. Repeated applications with the same diagnosis in 10 days after the first presentation were ignored. Compared to the pre-outbreak, there was a 3.5-fold decrease in dermatology applications in the first month after COVID-19 and an 8.8-fold in the second month. We found a significant increase in the frequency of diagnoses such as generalized pruritus, pityriasis rosea, alopecia areata, bacterial skin/mucosa diseases, and zona zoster after COVID-19. The frequency declined in diseases such as verruca vulgaris, hyperpigmentation, skin tag, melanocytic nevus, and seborrheic keratosis/solar lentigo. It has been found that the frequencies of most diseases, including acne (⁓25% of patients), did not change. We think that many factors, such as affecting the quality of life, risk perception, increased stress burden may cause a change in the diagnostic distribution of the dermatology applications., (© 2020 Wiley Periodicals LLC.)

COVID-19, first appeared in December 2019 in Wuhan, China, has been spreading quickly throughout the world. We reviewed the evidence on cutaneous manifestations of COVID-19 based on PubMed database. The searching strategy was (COVID* or coronavirus*) and (dermatol* or skin* or cutaneous*). The publication time was limited to 2019 onward. After independent review by two authors, 14 studies with 228 confirmed cases were included in the analysis. A total of 60 patients developed skin rashes, and the age ranged from 8 to 84. Exanthematous eruptions potentially related to COVID-19 infection were highly variable and heterogeneous. Skin lesions mainly appeared erythematous, urticarial, and vesicular (chicken pox-like or varicelliform). Petechiae rash, livedo reticularis, and reactivation of oral HSV-1 were also observed in single cases. Newly reported eruptions like vascular lesions and peculiar (perniosis-like) skin lesions caused concern among dermatologists. Exanthems were widely distributed and were primarily located on the trunk. Associated symptoms, latency time, treatment, and prognosis were also carefully summarized. This study reviewed the recently published COVID-19 studies with skin manifestations, which may pave the way for further research., (© 2020 Wiley Periodicals LLC.)

The study and applications of in vivo skin optics have been openly documented as early as the year 1954, or possibly earlier. To date, challenges in analyzing the complexities of this field remain, with wide scopes requiring more scrutiny. Recent advances in spectroscopic research and multivariate analytics allow a closer look into applications potentially for detecting or monitoring diseases. One of the challenges in this field is in establishing a reference for applications which correspond to certain bandwidths. This article reviews the scope on past research on skin spectroscopy, and the clinical aspects which have or may have applications on disease detection or enhancing diagnostics. A summary is supplied on the technicalities surrounding the measurements reported in literature, focused towards the wavelength-dependent applications in themes central to the respective research. Analytics on the topology of the papers' data cited in this work is also provided for a statistical perspective. In short, this paper strives to immediately inform the reader with possible applications via the spectroscopic devices at hand. Graphical Abstract .

In vivo reflectance confocal microscopy (RCM) enables clinicians to examine lesions' morphological and cytological information in epidermal and dermal layers while reducing the need for biopsies. As RCM is being adopted more widely, the workflow is expanding from real-time diagnosis at the bedside to include a capture, store, and forward model with image interpretation and diagnosis occurring offsite, similar to radiology. As the patient may no longer be present at the time of image interpretation, quality assurance is key during image acquisition. Herein, we introduce a quality assurance process by means of automatically quantifying diagnostically uninformative areas within the lesional area by using RCM and coregistered dermoscopy images together. We trained and validated a pixel-level segmentation model on 117 RCM mosaics collected by international collaborators. The model delineates diagnostically uninformative areas with 82% sensitivity and 93% specificity. We further tested the model on a separate set of 372 coregistered RCM-dermoscopic image pairs and illustrate how the results of the RCM-only model can be improved via a multimodal (RCM + dermoscopy) approach, which can help quantify the uninformative regions within the lesional area. Our data suggest that machine learning-based automatic quantification offers a feasible objective quality control measure for RCM imaging., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Acquired perforating dermatosis (APD) comprises an uncommon group of skin disorders that develop in adulthood in association with systemic diseases. The aim of this study was to characterize clinicopathologic features and treatment outcomes in a series of patients diagnosed with APD., Methods: Retrospective study of all patients diagnosed with an APD over a 10-year period (2009-2018) at a tertiary teaching hospital in Lisbon, Portugal., Results: Fifty-seven patients with APD were identified. Thirty-five patients presented lesions in multiple anatomic areas (61.4%), and the lower limbs were the most common location. Forty-six patients reported pruritus (80.7%), which was classified as severe in 21 of them (36.8%). An underlying systemic disease was identified in 53 patients (93.0%). Diabetes mellitus (DM) and chronic kidney disease (CKD) were the most common associated systemic diseases, but psychiatric disorders, malignancies, and chronic infections were present in a significant number of patients. The combination of topical steroids with antihistamines was the most prescribed initial treatment, but only 37.8% of the patients had a complete response. Acitretin, systemic steroids, and phototherapy were the treatments associated with the best outcome., Conclusion: Acquired perforating dermatosis can be associated with many systemic disorders that have pruritus as a common factor. Chronic viral infections and an occult malignancy should be sought, particularly in the absence of DM and CKD. The management of APD is challenging and is best achieved with the control of the underlying systemic diseases., (© 2019 The International Society of Dermatology.)

Background: Dermatologists play an important role in diagnosing and managing hospitalized patients with cutaneous abnormalities. Skin biopsies remain an indispensable tool for aiding dermatologists in accurate diagnosis and treatment. We aimed to determine the range of conditions, and the most common conditions, prompting skin biopsy by dermatology hospital consultation (HCON) services to aid in evaluation of hospitalized patients., Methods: All hospitalized patients seen by a single tertiary care center dermatology HCON service between 2015 and 2018 who had associated skin biopsies were identified. Histologic features and clinical diagnoses of each patient were classified into 13 histologic reaction pattern categories., Results: Eight hundred and thirty one inpatients evaluated by our dermatology HCON service had 914 skin biopsies. The most frequent diagnostic categories prompting biopsy were vasculopathic (17.6%), interface dermatitis (16.5%), infectious (12.6%), and spongiotic dermatitis (10.9%). The most frequent diagnostic categories included drug reaction (13.2%), leukocytoclastic vasculitis (8.5%), skin cancer (5.4%), graft-vs-host disease (3.5%), connective tissue disease (3.3%), and calciphylaxis (3.0%)., Conclusion: Our study suggests a variety of serious diseases affecting inpatients prompts biopsy by dermatology consultation services. Educational curricula for dermatology and pathology residents, fellows, and staff designed with these data may enhance knowledge that improves the quality of inpatient dermatology care., (© 2019 The Authors. Journal of Cutaneous Pathology published by John Wiley & Sons Ltd.)

Deep learning is a branch of artificial intelligence that uses computational networks inspired by the human brain to extract patterns from raw data. Development and application of deep learning methods for image analysis, including classification, segmentation, and restoration, have accelerated in the last decade. These tools have been progressively incorporated into several research fields, opening new avenues in the analysis of biomedical imaging. Recently, the application of deep learning to dermatological images has shown great potential. Deep learning algorithms have shown performance comparable with humans in classifying skin lesion images into different skin cancer categories. The potential relevance of deep learning to the clinical realm created the need for researchers in disciplines other than computer science to understand its fundamentals. In this paper, we introduce the basics of a deep learning architecture for image classification, the convolutional neural network, in a manner accessible to nonexperts. We explain its fundamental operation, the convolution, and describe the metrics for the evaluation of its performance. These concepts are important to interpret and evaluate scientific publications involving these tools. We also present examples of recent applications for dermatology. We further discuss the capabilities and limitations of these artificial intelligence-based methods., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Langerhans cell histiocytosis (LCH) is an uncommon but serious inflammatory neoplasia that affects many organs, including the skin. Though uncommon, it should remain high on a clinician's differential diagnosis in treatment-resistant cases of conditions, such as seborrheic dermatitis, diaper dermatitis, arthropod bites, and many more. A thorough history nd physical examination for each patient can aid in the diagnosis; however, if clinically suspicious for LCH, a punch biopsy should be performed. Histologic evaluation of LCH is often enough to differentiate it from the many clinical mimickers. Characteristic findings include a histiocytic infiltrate with "coffee bean"-cleaved nuclei, rounded shape, and eosinophilic cytoplasm. Immunohistochemical stains, including CD1a, S100, and CD207 (langerin) are often needed for a definitive diagnosis. Electron microscopy also demonstrates the ultrastructural presence of Birbeck granules, but this is no longer needed due to immunohistochemical staining. Treatment is often necessary for LCH, if systemic involvement exists., (Copyright © 2019. Published by Elsevier Inc.)