Chilblain-like lesions during COVID-19 epidemic: a preliminary study on 63 patients

Defining the short-term and long-term skin manifestations of COVID-19: insights after more than three years of the pandemic

AIM

This review aimed to assess the impact of coronavirus disease 2019 (COVID-19) on skin health to establish a classification of the skin lesions that occur most frequently during the disease and whether a particular category of skin damage is more likely to occur both in the short term and in the long term.

METHODS

We conducted a literature search of the PubMed database. Ultimately, 109 articles were included in this review. The exact phrases∕syntax and connectors used for the database search∕query were as follows: "Coronavirus and skin", "COVID-19 and skin", "SARS-CoV-2 and skin", "Coronavirus cutaneous manifestations", "COVID-19 cutaneous manifestations", "SARS-CoV-2 cutaneous manifestations", "Coronavirus dermatology", "SARS-CoV-2 and dermatology", "COVID-19 and dermatology", "COVID-19 and skin eruption", "Coronavirus and skin rash", "COVID-19 and hair", "Coronavirus and hair", "Coronavirus and nails", "SARS-CoV-2 and hair", and "SARS-CoV-2 and nails". Only articles with abstracts referring strictly to cutaneous manifestations of COVID-19 were chosen. Articles without abstracts were not considered.

RESULTS

We established six of the most frequently reported clinical patterns associated with COVID-19 and their probability of occurring during COVID-19 disease evolution based on the current literature reports. We did not identify the particular types of skin lesions that are most prone to long-term persistence; most such cases are rare, and no conclusion can be drawn based on them.

CONCLUSIONS

Apart from classified COVID-19-related skin disorders, this pandemic has been a challenge for dermatologists and a wide range of cutaneous side effects related to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) treatments have been reported. We are aware of other polymorphic clinical presentations, with novel data being reported periodically, but the pathophysiological mechanisms and evolution are largely unknown.

3D deconvolution of human skin immune architecture with Multiplex Annotated Tissue Imaging System

Routine clinical assays, such as conventional immunohistochemistry, often fail to resolve the regional heterogeneity of complex inflammatory skin conditions. We introduce MANTIS (Multiplex Annotated Tissue Imaging System), a flexible analytic pipeline compatible with routine practice, specifically designed for spatially resolved immune phenotyping of the skin in experimental or clinical samples. On the basis of phenotype attribution matrices coupled to α-shape algorithms, MANTIS projects a representative digital immune landscape while enabling automated detection of major inflammatory clusters and concomitant single-cell data quantification of biomarkers. We observed that severe pathological lesions from systemic lupus erythematosus, Kawasaki syndrome, or COVID-19-associated skin manifestations share common quantitative immune features while displaying a nonrandom distribution of cells with the formation of disease-specific dermal immune structures. Given its accuracy and flexibility, MANTIS is designed to solve the spatial organization of complex immune environments to better apprehend the pathophysiology of skin manifestations.

Skin Manifestations Among Patients Admitted with COVID-19: A Cross-Sectional Study at a University-Based Tertiary Hospital in Jordan

Background

COVID-19 pandemic hit the entire world with severe health and economic consequences. Although the infection primarily affected the respiratory system, it was soon recognized that COVID-19 has a multi-systemic component with various manifestations including cutaneous involvement.

Objective

The main objective of this study is to assess the incidence and patterns of cutaneous manifestations among moderate-to-severe COVID-19 patients who required hospitalization and whether there was a prognostic indication for cutaneous involvement and the outcome in terms of recovery or death.

Methods

This is a cross-sectional observational study that included inpatients who were diagnosed with a moderate or severe COVID-19 infection. The demographic and clinical data of patients were assessed including age, sex, smoking, and comorbidities. All patients were examined clinically for the presence of skin manifestations. Patients were followed for the outcome of COVID-19 infection.

Results

A total of 821 patients (356 females and 465 males) aged 4-95 years were included. More than half of patients (54.6%) aged >60 years. A total of 678 patients (82.6%) had at least one comorbid condition, mostly hypertension and diabetes mellitus. Sixty-two patients (7.55%) developed rashes; 5.24% cutaneous and 2.31% oral. The rashes were then grouped into five major types: group A, Exanthema: morbilliform, papulovesicular, varicella-like. Group B, Vascular: Chilblain-like lesions, purpuric/petechial, livedoid lesions. Group C, Reactive erythemas: Urticaria, Erythema multiforme. Group D, other skin rashes including flare-up of pre-existing disease, and O for oral involvement. Most patients (70%) developed rash after admission. The most frequent skin rashes were reactive erythema (23.3%), followed by vascular (20.9%), exanthema (16.3%), and other rashes with flare-ups of pre-existing diseases (39.5%). Smoking and loss of taste were associated with the appearance of various skin rashes. However, no prognostic implications were found between cutaneous manifestations and outcome.

Conclusion

COVID-19 infection may present with various skin manifestations including worsening of pre-existing skin diseases.

The pathogenesis of coronavirus-19 disease

Severe acute respiratory syndrome-associated coronavirus-2 (SARS-CoV-2) is the causal agent of coronavirus disease-2019 (COVID-19), a systemic illness characterized by variably severe pulmonary symptoms, cardiac conduction abnormalities, diarrhea, and gastrointestinal bleeding, as well as neurologic deficits, renal insufficiency, myalgias, endocrine abnormalities, and other perturbations that reflect widespread microvascular injury and a pro-inflammatory state. The mechanisms underlying the various manifestations of viral infection are incompletely understood but most data suggest that severe COVID-19 results from virus-driven perturbations in the immune system and resultant tissue injury. Aberrant interferon-related responses lead to alterations in cytokine elaboration that deplete resident immune cells while simultaneously recruiting hyperactive macrophages and functionally altered neutrophils, thereby tipping the balance from adaptive immunity to innate immunity. Disproportionate activation of these macrophages and neutrophils further depletes normal activity of B-cells, T-cells, and natural killer (NK) cells. In addition, this pro-inflammatory state stimulates uncontrolled complement activation and development of neutrophil extracellular traps (NETS), both of which promote the coagulation cascade and induce a state of “thrombo-inflammation”. These perturbations have similar manifestations in multiple organ systems, which frequently show pathologic findings related to microvascular injury and thrombosis of large and small vessels. However, the pulmonary findings in patients with severe COVID-19 are generally more pronounced than those of other organs. Not only do they feature inflammatory thromboses and endothelial injury, but much of the parenchymal damage stems from failed maturation of alveolar pneumocytes, interactions between type 2 pneumocytes and non-resident macrophages, and a greater degree of NET formation. The purpose of this review is to discuss the pathogenesis underlying organ damage that can occur in patients with SARS-CoV-2 infection. Understanding these mechanisms of injury is important to development of future therapies for patients with COVID-19, many of which will likely target specific components of the immune system, particularly NET induction, pro-inflammatory cytokines, and subpopulations of immune cells.

Effect of stimulated platelets in COVID-19 thrombosis: Role of alpha7 nicotinic acetylcholine receptor

Since early 2020, SARS-CoV-2-induced infection resulted in global pandemics with high morbidity, especially in the adult population. COVID-19 is a highly prothrombotic condition associated with subsequent multiorgan failure and lethal outcomes. The exact mechanism of the prothrombotic state is not well understood and might be multifactorial. Nevertheless, platelets are attributed to play a crucial role in COVID-19-associated thrombosis. To date, platelets' role was defined primarily in thrombosis and homeostasis. Currently, more focus has been set on their part in inflammation and immunity. Moreover, their ability to release various soluble factors under activation as well as internalize and degrade specific pathogens has been highly addressed in viral research. This review article will discuss platelet role in COVID-19-associated thrombosis and their role in the cholinergic anti-inflammatory pathway. Multiple studies confirmed that platelets display a hyperactivated phenotype in COVID-19 patients. Critically ill patients demonstrate increased platelet activation markers such as P-selectin, PF4, or serotonin. In addition, platelets contain acetylcholine and express α7 nicotinic acetylcholine receptors (α7nAchR). Thus, acetylcholine can be released under activation, and α7nAchR can be stimulated in an autocrine manner and support platelet function. α7 receptor is one of the most important mediators of the anti-inflammatory properties as it is associated with humoral and intrinsic immunity and was demonstrated to contribute to better outcomes in COVID-19 patients when under stimulation. Hematopoietic α7nAchR deficiency increases platelet activation and, in experimental studies, α7nAchR stimulation can diminish the pro-inflammatory state and modulate platelet reactiveness via increased levels of NO. NO has been described to inhibit platelet adhesion, activation, and aggregation. In addition, acetylcholine has been demonstrated to decrease platelet aggregation possibly by blocking the e p-38 pathway. SARS-CoV-2 proteins have been found to be similar to neurotoxins which can bind to nAChR and prevent the action of acetylcholine. Concluding, the platelet role in COVID-19 thrombotic events could be explained by their active function in the cholinergic anti-inflammatory pathway.

SARS-CoV-2 Vaccination and Chilblain-like Lesions: What Do We Know so Far?

INTRODUCTION

The coronavirus pandemic has caused massive damage to global health care and the economy. The vaccination program has been paced around the globe to return as soon as possible to pre-COVID time. Although all the vaccines have been approved after the rigorous clinical and safety trials, some adverse effects have surfaced and are being reported from different parts of the world. One such side effect is chilblain-like lesions following the COVID vaccination. Chilblain lesions, also known as pernio, are an inflammatory condition usually affecting the acral regions of the body. It is mostly reported from cold and damp areas and has multiple causes associated with it.

OBJECTIVE

This study aims to review the publicly available data and to provide concise and comprehensive information as well as evaluate the potential pathology, clinical approach, and management of CLL post-vaccination.

METHODS

An extensive literature search over PubMed, Cochrane library, Google Scholar, and Clinicaltrails. gov from inception till 5th October 2021, without any restriction of language was carried out. All the recruited articles were reviewed, and their bibliographies were also screened for any relevant information.

RESULTS

12 studies (10 case reports and 2 case series) were retrieved reporting the incidence of CLL post-vaccination. 8 studies reported incidence in female patients while 5 reported in males, with one study mentioning no gender. Moreover, most of them were either from Europe or the United States of America, except for two cases, reported from Turkey.

CONCLUSIONS

Although the overall incidence of Chilblains following COVID-19 vaccination is low, there is still a strong need to find out the exact mechanism behind this to redefine the safety and administration criteria of the vaccines and to formulate a proper management protocol.

Cutaneous Manifestations of COVID-19 in the Lower Limbs: A Narrative Review

In 2020, the World Health Organization declared the COVID-19 pandemic. This infectious pathology can be associated with different manifestations in different body systems, among which are dermatological lesions. The purpose of this work is to determine the most frequent dermatological signs, in the lower limbs, produced by SARS-CoV-2. To carry this out, a bibliographic search was performed in the following databases: PubMed, SciELO, ScienceDirect, Cochrane Database of Systematic Reviews, and the Google Scholar literature. The inclusion criteria were articles that included confirmed subjects or those with a clinical suspicion of COVID-19, written in the Spanish or English languages, and the results presented clinical manifestations in the lower extremities. Initially, 128 scientific documents were identified and, after reading the title and abstract, 18 articles were selected. The most frequent skin lesions on the lower limbs are acral lesions such as pernio erythema or ischemic lesions, maculopapular rash, petechiae, and erythematous plaques.

COVID-19 disease and autoimmune disorders: A mutual pathway

Coronavirus disease 2019 (COVID-19) is a real challenge for humanity with high morbidity and mortality. Despite being primarily a respiratory illness, COVID-19 can affect nearly every human body tissue, causing many diseases. After viral infection, the immune system can recognize the viral antigens presented by the immune cells. This immune response is usually controlled and terminated once the infection is aborted. Nevertheless, in some patients, the immune reaction becomes out of control with the development of autoimmune diseases. Several human tissue antigens showed a strong response with antibodies directed against many severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) proteins, such as SARS-CoV-2 S, N, and autoimmune target proteins. The immunogenic effects of SARS-CoV-2 are due to the sizeable viral RNA molecules with interrupted transcription increasing the pool of epitopes with increased chances of molecular mimicry and interaction with the host immune system, the overlap between some viral and human peptides, the viral induced-tissue damage, and the robust and complex binding between sACE-2 and SARS-CoV-2 S protein. Consequently, COVID-19 and its vaccine may trigger the development of many autoimmune diseases in a predisposed patient. This review discusses the mutual relation between COVID-19 and autoimmune diseases, their interactive effects on each other, the role of the COVID-19 vaccine in triggering autoimmune diseases, the factors affecting the severity of COVID-19 in patients suffering from autoimmune diseases, and the different ways to minimize the risk of COVID-19 in patients with autoimmune diseases.

The Impact of COVID-19 Pandemic on Dermatological Conditions: A Novel, Comprehensive Review

Background: The earliest cases of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) emerged in Wuhan, China, in December 2019. Since the declaration as a pandemic on 11 March 2020, further dermatological conditions continue to be documented. We herein present a novel literature review of dermatological manifestations associated with the Coronavirus Disease 2019 (COVID-19) pandemic. To date, this literature review is the first broad-spectrum examination that analyzes a range of dermatological manifestations related to the COVID-19 pandemic: infection, vaccinations, personal protective equipment (PPE), and psychosocial factors. Methods: A detailed literature search was conducted using key terms for cutaneous manifestations associated with the scope of this review. The search retrieved 2199 articles. Results: The COVID-19 pandemic has triggered a significant range of dermatologic sequela. Etiologies of lesions continue to be investigated. Proposed mechanisms include inflammatory response to spike protein, vitamin D deficiency, ACE2 receptor activation, androgen levels, and increased psychological stress. One prominent mechanism describes viral spike protein invasion into the dermis by binding to the angiotensin-converting enzyme 2 (ACE-2) receptors in keratinocytes, with a secondary immunological response. Conclusions: Dermatologists play an integral role in the proper diagnosis and treatment of COVID-related lesions. Early treatment regimens and timely prophylaxis have been shown to safely reduce infection-related dermatological sequelae. Additional investigations and data collection can reduce disease burden and improve overall prognosis.

COVID-19 and cutaneous manifestations: Two cases and a review of the literature

COVID-19 can affect multiple organs, including skin. A wide range of skin manifestations have been reported in literature. Six main phenotypes have been identified: i) urticarial rash, ii) confluent erythematous/maculopapular/morbilliform rash, iii) papulovesicular exanthem, iv) a chilblain-like acral pattern, v) a livedo reticularis/racemosa-like pattern, and vi) a purpuric vasculitic pattern. The pathogenetic mechanism is still not completely clear, but a role of hyperactive immune response, complement activation and microvascular injury have been postulated. The only correlation between the cutaneous phenotype and the severity of COVID-19 has been observed in the case of chilblain-like acral lesions, that is generally associated with the benign/subclinical course of COVID-19. Herein, we report two cases of SARS-CoV- 2 infection in patients who developed cutaneous manifestations that completely solved with systemic steroids and antihistamines. The first case is a female patient not vaccinated for SARS-CoV-2 with COVID-19 associated pneumonia, while the second case is a vaccinated female patient with only skin manifestations.

COVID-19 cutaneous manifestations in children and adolescents: a systematic review

Objective:

The aim of this study was to evaluate the coronavirus disease 2019 (COVID-19) cutaneous manifestations described in pediatric patients and discuss their relevance for early diagnosis.

Data source:

The study consisted of a systematic review of original articles indexed in PubMed and Embase databases, as well as gray literature articles found through Google Scholar. A search strategy, based on PICO (Patient, Intervention, Comparison, Outcome) Tool, with the terms “child,” “infant,” “childhood,” “adolescents,” “teenagers,” “COVID-19,” “SARS-CoV-2,” and “skin manifestations,” was performed to optimize the findings. The study did not restrict any article regarding language.

Data synthesis:

Out of the 310 articles that initially met the inclusion criteria, 35 were selected for review, totalizing 369 patients. The most common COVID-19 cutaneous manifestations in children and adolescents were Chilblain-like lesions, presented in 67.5% of the cases, followed by erythema multiforme-like (31.7%) and varicella-like lesions (0.8%). The Chilblain-like lesions appeared 7.6 days (95%CI 7.4–7.8) after the viral infection and lasted for 17.5 days (95%CI 16.5–18.5), erythema multiforme-like lesions appeared in 9.5 days (95%CI 9–10) and lasted for 10.3 days (95%CI 9.1–11.5), and varicella-like lesions appeared in 12.3 days (95%CI 4–20.6) and lasted for 7 days.

Conclusions:

Knowledge of the different skin manifestations in children and adolescents with COVID-19 is essential for an early diagnosis and, consequently, the possibility of promptly care adoption as well as to interrupt the new coronavirus transmission chains in the current pandemic context.

[Skin and SARS-CoV-2 in pediatrics]

The clinical presentation, disease course, and outcome of SARS-CoV-2 infection in pediatrics differ from the presentation in adults. In a review by Hoang et al., the prevalence of dermatological manifestations was estimated in 0.25% of a total of 2,445 children with confirmed COVID-19. Similarly, the prevalence of skin manifestations was reported in 3% of 100 children in the Parri's study. A systematic review by Shah et al. analyzed 13 studies with 149 children who met eligibility criteria. The acral erythematous maculopapular lesion was the most common, as well as erythema multiforme, varicella rash, and presentations similar to Kawasaki disease. The duration of the skin lesion was one to two weeks in 43%. Skin biopsy of 18 cases complete superficial and deep perivascular and paracrine lymphocytic infiltrate and lymphocytic vasculitis were reported. RT-PCR was positive in 13.8 % of the cases. The serological markers of herpes simplex virus and parvovirus B19 analyzed were negative, except for Mycoplasma pneumoniae in two of 20 cases. The pathophysiological mechanism of skin lesions secondary to SARS-CoV-2 infection has not yet been explained; likely to be a combination of one or more complex mechanisms, direct skin damages induced by the virus, vasculitis-like reactions either indirect or secondary injuries as a consequence of a systemic inflammatory reaction. Publications from years 2019 to 2021 are reviewed in PubMed as the main search source, using key words.

Lack of association between pandemic chilblains and SARS-CoV-2 infection

An increased incidence of chilblains has been observed during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic and attributed to viral infection. Direct evidence of this relationship has been limited, however, as most cases do not have molecular evidence of prior SARS-CoV-2 infection with PCR or antibodies. We enrolled a cohort of 23 patients who were diagnosed and managed as having SARS-CoV-2-associated skin eruptions (including 21 pandemic chilblains [PC]) during the first wave of the pandemic in Connecticut. Antibody responses were determined through endpoint titration enzyme-linked immunosorbent assay and serum epitope repertoire analysis. T cell responses to SARS-CoV-2 were assessed by T cell receptor sequencing and in vitro SARS-CoV-2 antigen-specific peptide stimulation assays. Immunohistochemical and PCR studies of PC biopsies and tissue microarrays for evidence of SARS-CoV-2 were performed. Among patients diagnosed and managed as "covid toes" during the pandemic, we find a percentage of prior SARS-CoV-2 infection (9.5%) that approximates background seroprevalence (8.5%) at the time. Immunohistochemistry studies suggest that SARS-CoV-2 staining in PC biopsies may not be from SARS-CoV-2. Our results do not support SARS-CoV-2 as the causative agent of pandemic chilblains; however, our study does not exclude the possibility of SARS-CoV-2 seronegative abortive infections.

New use of old medicine: Nifedipine acts on the TRP family and inflammatory proteins in the treatment of chilblain

As a calcium antagonist, the mechanism of nifedipine for treating chilblain has not been reported. In the present study, we established the chilblain model by using -20 ℃ 95% ethanol to freeze the right back foot of SD rats, and investigated the effects of this drug. Hematoxylin-eosin (HE) examination indicated most of pannus in the skin tissue of chilblain rats had disappeared, and the local inflammatory cells were also greatly reduced when given nifedipine at 15.0 mg/kg/d. The enzyme-linked immunosorbent assay (ELISA) revealed that nifedipine inhibited release of inflammatory factors TNF-α, IL-6, IL-1β and VEGF in serum. The RT-PCR analysis showed that nifedipine down regulated mRNA levels of TRPC-6 and VEGF in skin tissue. Furthermore, immunohistochemical examination showed nifedipine inhibited expression of IL-1β, IL-6, and TNF-α inflammatory protein and further inhibited expression of TRP (transient receptor potential) family proteins TRPM-7, TRPC-1, TRPC-3 and TRPC-6 and reduced expression of VEGF in skin and relieved erythema and oedema. This study demonstrated that nifedipine as an old medicine can be new use for the treatment of chilblain by acting on TRPs family and inflammatory proteins.

Cutaneous manifestation of COVID-19: What have we learned an year into the pandemic?

Coronavirus disease-19 (COVID-19) is an emerging health situation caused by the "severe acute respiratory syndrome coronavirus 2" (SARS-CoV-2). The ongoing COVID-19 pandemic which emerged from the Chinese city of Wuhan in December 2019 has spread to over 188 countries and infected over 100 million people across the globe in over one year. Most common symptoms of COVID-19 include fever and respiratory illness. Among extrapulmonary signs associated with COVID-19, dermatological manifestations have been increasingly reported from different geographical regions. The exact incidence or prevalence of COVID-19 associated skin manifestation remains largely unknown and the pathophysiological mechanisms are still unclear. In this article, we have attempted to give a comprehensive overview of what has been learned an year into the pandemic on the epidemiology, clinical and histopathological features, pathophysiological mechanisms and clinical management of COVID-19 associated cutaneous manifestations.

Experience with Cutaneous Manifestations in COVID-19 Patients during the Pandemic

After the beginning of the SARS-CoV-2 pandemic, our dermatology department created a multidisciplinary unit to manage patients with cutaneous manifestations associated with COVID-19. With the objective of identifying skin lesions in patients with suspected COVID-19 and evaluating possible associations with systemic involvement, other infectious agents and coagulation disorders, we carried out a prospective observational study that included all patients that attended our COVID-19 dermatology clinic with a multidisciplinary protocol. A total of 63 patients (mean 34.6 years) were enrolled between May 2020 and February 2021. Overall, 27 patients (42.9%) had a positive COVID-19 test, and 74.6% had COVID-19 clinical signs. The most common skin lesion was maculopapular rash (36.5%), predominantly seen in male (54.2%) and older patients (42 vs. 30 years), followed by chilblain-like lesions (20.6%) in younger patients (13.9 vs. 20.9 years) who were predominantly barefoot at home (69.2%); these patients exhibited a tendency towards a negative COVID-19 test. A total of 12 patients (19.1%) had positive serology for herpesvirus 6 (IgM or IgG). We conclude that the COVID-19-associated skin lesions we observed were similar to those previously described. Questions as to the underlying mechanisms remain. Interferon, possibly aided by cold exposure, may cause perniosis-like lesions. Other cutaneous manifestations were similar to those caused by other viruses, suggesting that SARS-CoV-2 may reactivate or facilitate other viral infections.

Chilblain or Perniosis-like Skin Lesions in children during the COVID-19 pandemic: A Systematic Review of Articles

COVID toes or chilblain-like skin lesions represent a widespread and specific skin presentation in the feet attributed to COVID-19 infection. They may last for several months. We conducted this study to investigate chilblain-like lesions in children during the COVID-19 pandemic, any predisposition, location, clinical course, and prognosis. We searched Google Scholar, Scopus, and Medline (PubMed) databases using the following keywords: "Coronavirus" OR "COVID-19" AND "Chilblains" OR "Pernio" OR "Perniosis" OR "Children" OR "Cutaneous" OR "skin." The inclusion criteria were: studies that described the specific vascular skin lesion. studies that included patients that were aged > one month till 18 years. . Case reports, case series, retrospective or prospective cohort studies, case-control studies. Twenty-eight articles were included. The total number of children with CLL was 433. The mean age of children presenting CLL during the COVID-19 pandemic was estimated as 12.58 ± 2.15. Of note, 53.6% of them were male. The nasopharyngeal SARS-CoV-2 RT-PCR test and anti-SARS-CoV-2 antibodies were mostly negative for the virus. In conclusion, it is crucial to be familiar with various presentations of COVID-19 infection and their clinical significance to approach the earliest diagnosis, immediate treatment, estimate the prognosis and finally isolate the patients to prevent spreading. Chilblain-like lesions as a possible cutaneous presentation of COVID-19 in children may last several months with the indolent course.

Automatic Segmentation of Novel Coronavirus Pneumonia Lesions in CT Images Utilizing Deep-Supervised Ensemble Learning Network

Background: The novel coronavirus disease 2019 (COVID-19) has been spread widely in the world, causing a huge threat to the living environment of people. Objective: Under CT imaging, the structure features of COVID-19 lesions are complicated and varied greatly in different cases. To accurately locate COVID-19 lesions and assist doctors to make the best diagnosis and treatment plan, a deep-supervised ensemble learning network is presented for COVID-19 lesion segmentation in CT images. Methods: Since a large number of COVID-19 CT images and the corresponding lesion annotations are difficult to obtain, a transfer learning strategy is employed to make up for the shortcoming and alleviate the overfitting problem. Based on the reality that traditional single deep learning framework is difficult to extract complicated and varied COVID-19 lesion features effectively that may cause some lesions to be undetected. To overcome the problem, a deep-supervised ensemble learning network is presented to combine with local and global features for COVID-19 lesion segmentation. Results: The performance of the proposed method was validated in experiments with a publicly available dataset. Compared with manual annotations, the proposed method acquired a high intersection over union (IoU) of 0.7279 and a low Hausdorff distance (H) of 92.4604. Conclusion: A deep-supervised ensemble learning network was presented for coronavirus pneumonia lesion segmentation in CT images. The effectiveness of the proposed method was verified by visual inspection and quantitative evaluation. Experimental results indicated that the proposed method has a good performance in COVID-19 lesion segmentation.

Snotwatch COVID-toes: An ecological study of chilblains and COVID-19 diagnoses in Victoria, Australia

The COVID-19 pandemic has caused widespread illness with varying clinical manifestations. One less-commonly-reported presentation of COVID-19 infection is chilblain-like lesions. We conducted an ecological analysis of chilblain presentations in comparison with confirmed and suspected COVID-19 infections in a primary care setting to establish that a relationship exists between the two. Our study collated data from three Primary Health Networks across Victoria, Australia, from 2017-2021, to understand patterns of chilblain presentations prior to and throughout the pandemic. Using a zero-inflated negative binomial regression analysis, we estimated the relationship between local minimum temperature, COVID-19 infections and the frequency of chilblain presentations. We found a 5.72 risk ratio of chilblain incidence in relation to COVID-19 infections and a 3.23 risk ratio associated with suspected COVID-19 infections. COVID-19 infections were also more strongly associated with chilblain presentations in 0-16-year-olds throughout the pandemic in Victoria. Our study statistically suggests that chilblains are significantly associated with COVID-19 infections in a primary care setting. This has major implications for clinicians aiming to diagnose COVID-19 infections or determine the cause of a presentation of chilblains. Additionally, we demonstrate the utility of large-scale primary care data in identifying an uncommon manifestation of COVID-19 infections, which will be significantly beneficial to treating physicians.

Manifestações cutâneas da COVID-19 em crianças e adolescentes: uma revisão sistemática

RESUMO Objetivo: Avaliar as manifestações cutâneas da Doença de Coronavírus 2019 (COVID-19) descritas em pacientes pediátricos e discutir sua relevância para o diagnóstico precoce. Fontes de dados: O estudo consistiu em uma revisão sistemática de artigos originais indexados nas bases de dados PubMed e Embase, assim como na literatura cinzenta localizados via Google Scholar. Uma estratégia de busca, baseada na PICO (Patient, Intervention, Comparison, Outcome) Tool, com os termos “child”, “infant”, “childhood”, “adolescents”, “teenagers”, “COVID-19”, “SARS-CoV-2” e “skin manifestations” foi conduzida para otimizar os achados. Não houve restrições de idiomas. Síntese de dados: 35 dos 310 artigos que inicialmente cumpriram os critérios de inclusão foram selecionados para revisão, totalizando 369 pacientes. As manifestações cutâneas mais comuns de COVID-19 em crianças e adolescentes foram as lesões Chilblain-Like presentes em 67,5% dos casos, seguidas pelas lesões Eritema Multiforme-Like (31,7%) e Varicella-Like (0,8%). As lesões Chilblain-Like surgiram 7,6 dias (IC95% 7,4–7,8) após a infecção viral e tiveram duração de 17,5 dias (IC95% 16,5–18,5); as lesões Eritema Multiforme-Like surgiram em 9,5 dias (IC95% 9–10) e duraram 10,3 dias (IC95% 9,1–11,5) e as lesões Varicella-Like apareceram em 12,3 dias (IC95% 4–20,6) e duraram 7 dias. Conclusões: O conhecimento das diferentes manifestações cutâneas em crianças e adolescentes com COVID-19 é essencial para o diagnóstico precoce da doença, assim como possibilitar adoção de prontos cuidados e interromper cadeias de transmissão do novo coronavírus.

Chilblains-Like Lesions in Pediatric Patients: A Review of Their Epidemiology, Etiology, Outcomes, and Treatment

Vascular pathologies associated with SARS-CoV-2 infection are poorly understood. Color and sensory changes to the extremities, often referred to as "COVID toes" or chilblains-like lesions, have been widely reported in children and adolescents since the onset of the pandemic, raising the concern that they could be a vasculitis secondary to the infection. However, it is unclear if the lesions are a result of the infection or an epiphenomenon. Most literature focuses on adults, and while there are reports on children and adolescents, many of them are small. This review will help medical care providers better understand the epidemiology, etiology, outcomes, and potential treatments for chilblains-like lesions seen in children and adolescents during the pandemic.

Clinicopathologic features among different viral epidemic outbreaks involving the skin

The current coronavirus disease 2019 pandemic has exceeded any epidemiologic prevision, but increasing information suggests some analogies with the major viral outbreaks in the last century, and a general warning has been issued on the possibility that coinfections can make the differential diagnosis and treatment difficult, especially in tropical countries. Some reports have noted that the presence of high dengue antibodies can give a false-negative result when testing for severe acute respiratory syndrome coronavirus 2. Mucocutaneous manifestations are very frequent, with an apparent overlap among different pathogens. However, strong clinicopathologic correlation might provide some clues to address differentials. Waiting for laboratory and instrumental results, the timing and distribution of skin lesions is often pathognomonic. Histopathologic findings characterize certain reaction patterns and provide insights on pathogenetic mechanisms. Unfortunately, skin assessment, especially invasive examinations such as biopsy, takes a back seat in severely ill patients. A literature retrieval was performed to collect information from other epidemics to counteract what has become the most frightening disease of our time.

Epidemiology and clinical evolution of non-multisystem inflammatory syndrome (MIS-C) dermatological lesions in pediatric patients affected by SARS-CoV-2 infection: A systematic review of the literature

COVID-19 can present with a range of skin manifestations, some of which specific of the pediatric age. The aim of this systematic literature review was to determine the type, prevalence, time of onset, and evolution of cutaneous manifestations associated with COVID-19 in newborns, children, and adolescents, after excluding multisystem inflammatory syndrome in children (MIS-C). PubMed, Tripdatabase, ClinicalTrials, and Cochrane Library databases were searched using an ad hoc string for case reports/series and observational studies, published between December 2019 and February 2022. Study quality was assessed using the STROBE and CARE tools. Seventy-three (49 case reports/series and 24 studies) out of 26,545 identified articles were included in the analysis. Dermatological lesions were highly heterogeneous for clinical presentation, time of onset, and association with other COVID-19 manifestations. Overall, they mainly affected the acral portions, and typically presented a favorable outcome. Pseudo-chilblains were the most common.

CONCLUSIONS

Mucocutaneous manifestations could be the only/predominant and early manifestation of COVID-19 that could precede other more severe manifestations by days or weeks. Therefore, physicians of all disciplines should be familiar with them.

WHAT IS KNOWN

• A variety of cutaneous manifestations have been reported in association with COVID-19. • Urticaria, maculopapular, or vesicular rashes can occur at any age, while chilblains and erythema multiforme are more common in children and young patients.

WHAT IS NEW

• Skin lesions related to SARS-CoV-2 infection often show a peculiar acral distribution. • Mucocutaneous lesions of various type may be the only/predominant manifestation of COVID-19; they could present in paucisymptomatic and severely ill patients and occur at different stages of the disease.

Case Report: Ciclosporin A for Refractory Multisystem Inflammatory Syndrome in Children

Multisystem inflammatory syndrome in children (MIS-C) is a new syndrome involving the development of severe dysfunction in multiple organs after severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection. Because the pathophysiology of MIS-C remains unclear, a treatment strategy has not yet been established. We experienced a 12-year-old boy who developed MIS-C at 56 days after SARS-CoV-2 infection and for whom ciclosporin A (CsA) was effective as a third-line treatment. He had a high fever on day 1, and developed a rash on the trunk, swelling in the cervical region, and palmar erythema on day 2. On days 3, he developed conjunctivitis and lip redness, and fulfilled the criteria for classical Kawasaki disease (KD). Although intravenous immunoglobulin infusion (IVIG) was started on day 4, fever persisted and respiratory distress and severe abdominal pain developed. On day 5, because he fulfilled the criteria for MIS-C, methylprednisolone pulse was started for 3 days as a second-line treatment. However, he did not exhibit defervescence and the symptoms continued. Therefore, we selected CsA as a third-line treatment. CsA was so effective that he became defervescent and his symptoms disappeared. In order to clarify the relationship with treatment and the change of clinical conditions, we examined the kinetics of 71 serum cytokines to determine their relationships with his clinical course during the three successive treatments. We found that CsA suppressed macrophage-activating cytokines such as, IL-12(p40), and IL-18 with improvement of his clinical symptoms. CsA may be a useful option for additional treatment of patients with MIS-C refractory to IVIG + methylprednisolone pulse.

From Your Nose to Your Toes: A Review of Severe Acute Respiratory Syndrome Coronavirus 2 Pandemic‒Associated Pernio

Despite thousands of reported patients with pandemic-associated pernio, low rates of seroconversion and PCR positivity have defied causative linkage to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Pernio in uninfected children is associated with monogenic disorders of excessive IFN-1 immunity, whereas severe COVID-19 pneumonia can result from insufficient IFN-1. Moreover, SARS-CoV-2 spike protein and robust IFN-1 response are seen in the skin of patients with pandemic-associated pernio, suggesting an excessive innate immune skin response to SARS-CoV-2. Understanding the pathophysiology of this phenomenon may elucidate the host mechanisms that drive a resilient immune response to SARS-CoV-2 and could produce relevant therapeutic targets.

Cutaneous coronavirus disease 2019 in children: a clinical primer for diagnosis and treatment

PURPOSE OF REVIEW

This review examines the global literature regarding rashes encountered in children and adults infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and aims to provide practicing pediatricians with an understanding of the relationship between instances of rashes and coronavirus disease 2019 (COVID-19) in children in order to effectively evaluate and treat patients.

RECENT FINDINGS

The true incidence of cutaneous reactions in children infected with SARS-CoV-2 is not known. Children's immune systems differ from those of adults and rashes as a manifestation of immune responses, in turn, differ in morphology and distribution. Rarely, children develop a severe multisystem inflammatory syndrome that has overlapping clinical features with Kawasaki disease. In addition, vaccinations produce rashes similar to natural infections. The rashes associated with COVID-19 vaccination are mild and transient, and should not preclude vaccination. Lastly, children who chronically wear masks are more likely to experience flaring of acne around the nose and mouth ('maskne') and facial conditions such as seborrheic dermatitis.

SUMMARY

There are ongoing worldwide registries, clinical and basic science studies to better understand the burden of skin disease and pathophysiology of rashes seen in patients infected with COVID-19. Robust vaccination programs should be encouraged as a way to contain viral spread among children and the greater population.

"COVID Toes" in Three Siblings

Dermatologists reported an outbreak of pernio (red to purple swollen painful toes) during the COVID-19 pandemic. Most subjects lacked positive CoV-19 polymerase chain reaction (PCR) or antibodies or a preceding illness. The dermatologists termed the illness "COVID toes." Pernio usually affects adults versus "COVID toes" usually children. Pernio is preceded by a clear history of exposure to wet and cold. Patients with "COVID toes" lack this history. Also, it is not unusual for multiple family members to have "COVID toes." Our case report describes "COVID toes" in an 18-year-old with no preceding illness, a negative SARS-CoV-19 PCR, and an initially negative SARS-CoV-19 antibody, and also his 2 siblings also developed "COVID toes." In our index case, repeat SARS-CoV-19 antibodies were positive. Seroconversion has rarely been reported in patients with "COVID toes." Why most "COVID toes" patients lack a clinical history of COVID-19 and are SARS-CoV-19 PCR and antibody negative is a mystery.

Cutaneous manifestation of COVID-19: What have we learned an year into the pandemic?

Coronavirus disease-19 (COVID-19) is an emerging health situation caused by the "severe acute respiratory syndrome coronavirus 2" (SARS-CoV-2). The ongoing COVID-19 pandemic which emerged from the Chinese city of Wuhan in December 2019 has spread to over 188 countries and infected over 100 million people across the globe in over one year. Most common symptoms of COVID-19 include fever and respiratory illness. Among extrapulmonary signs associated with COVID-19, dermatological manifestations have been increasingly reported from different geographical regions. The exact incidence or prevalence of COVID-19 associated skin manifestation remains largely unknown and the pathophysiological mechanisms are still unclear. In this article, we have attempted to give a comprehensive overview of what has been learned an year into the pandemic on the epidemiology, clinical and histopathological features, pathophysiological mechanisms and clinical management of COVID-19 associated cutaneous manifestations.

Molecular mechanisms of vasculopathy and coagulopathy in COVID-19

COVID-19 primarily affects the respiratory system and may lead to severe systemic complications, such as acute respiratory distress syndrome (ARDS), multiple organ failure, cytokine storm, and thromboembolic events. Depending on the immune status of the affected individual early disease control can be reached by a robust type-I-interferon (type-I-IFN) response restricting viral replication. If type-I-IFN upregulation is impaired, patients develop severe COVID-19 that involves profound alveolitis, endothelitis, complement activation, recruitment of immune cells, as well as immunothrombosis. In patients with proper initial disease control there can be a second flare of type-I-IFN release leading to post-COVID manifestation such as chilblain-like lesions that are characterized by thrombosis of small vessels in addition to an inflammatory infiltrate resembling lupus erythematosus (LE). Mechanistically, SARS-CoV-2 invades pneumocytes and endothelial cells by acting on angiotensin-II-converting enzyme 2 (ACE2). It is hypothesized, that viral uptake might downregulate ACE2 bioavailability and enhance angiotensin-II-derived pro-inflammatory and pro-thrombotic state. Since ACE2 is encoded on the X chromosome these conditions might also be influenced by gender-specific regulation. Taken together, SARS-CoV-2 infection affects the vascular compartment leading to variable thrombogenic or inflammatory response depending on the individual immune response status.

COVID-19 and Its Repercussions on Oral Health: A Review

In 2019, a new type of coronavirus, SARS-CoV-2, the causing agent of COVID-19, was first detected in Wuhan, China. On 11 March 2020, the World Health Organization declared a pandemic. The manifestations of COVID-19 are mostly age-dependent and potentially more severe in cases with involved co-morbidities. The gravity of the symptoms depends on the clinical stage of the infection. The most common symptoms include runny nose and nasal congestion, anosmia, dysgeusia or hypogeusia, diarrhea, nausea/vomiting, respiratory distress, fatigue, ocular symptoms, diarrhea, vomiting, and abdominal pain. These systemic conditions are often accompanied by skin and mucosal lesions. Oral lesions reported in patients with COVID-19 include: herpex simplex, candidiasis, geographic tongue, aphthous-like ulcers, hemorrhagic ulcerations, necrotic ulcerations, white hairy tongue, reddish macules, erythematous surfaces, petechiae, and pustular enanthema. It is still unclear if these manifestations are a direct result of the viral infection, a consequence of systemic deterioration, or adverse reactions to treatments. Poor oral hygiene in hospitalized or quarantined COVID-19 patients should also be considered as an aggravating condition. This narrative review is focused on presenting the most relevant data from the literature regarding oral manifestations related to SARS-CoV-2, as well as the challenges faced by the dental system during this pandemic. A routine intraoral examination is recommended in COVID-19 patients, either suspected or confirmed, as, in certain cases, oral manifestations represent a sign of severe infection or even of a life-threatening condition. It is our belief that extensive knowledge of all possible manifestations, including oral lesions, in cases of COVID-19 is of great importance in the present uncertain context, including new, currently emerging viral variants with unknown future impact.

The skin as a critical window in unveiling the pathophysiologic principles of COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiologic agent of coronavirus disease 2019 (COVID-19), is a single-stranded RNA virus whose sequence is known. COVID-19 is associated with a heterogeneous clinical phenotype ranging from asymptomatic to fatal disease. It appears that access to nasopharyngeal respiratory epithelia expressing angiotensin-converting enzyme (ACE) 2, the receptor for SARS-CoV-2, is followed by viral replication in the pulmonary alveolar septal capillary bed. We have demonstrated in earlier studies that incomplete viral particles, termed pseudovirions, dock to deep subcutaneous and other vascular beds, potentially contributing to the prothrombotic state and systemic complement activation that characterizes severe and critical COVID-19. A variety of skin eruptions have been described in the setting of SARS-CoV-2 infection and more recently, after COVID-19 vaccination. The vaccines deliver a laboratory-synthesized mRNA that encodes a protein that is identical to the spike glycoprotein of SARS-CoV-2, allowing the production of immunogenic spike glycoprotein that will then elicit T cell and B cell adaptive immune responses. In this contribution, we review an array of cutaneous manifestations of COVID-19 that provide an opportunity to study critical pathophysiologic mechanisms that underlie all clinical facets of COVID-19, ranging from asymptomatic/mild to severe and critical COVID-19. We classify cutaneous COVID-19 according to underlying pathophysiologic principles. In this regard we propose three main pathways: (1) complement mediated thrombotic vascular injury syndromes deploying the alternative and mannan binding lectin pathways and resulting in the elaboration of cytokines like interleukin 6 from endothelium in the setting of severe and critical COVID-19 and (2) the robust T cell and type I interferon-driven inflammatory and (3) humoral-driven immune complex mediated vasculitic cutaneous reactions observed with mild and moderate COVID-19. Presented are novel data on cutaneous vaccine reactions that manifest a clinical and morphologic parallel with similar eruptions observed in patients with mild and moderate COVID-19 and in some cases represent systemic eczematoid hypersensitivity reactions to a putative vaccine-based antigen versus unmasking subclinical hypersensitivity due to immune enhancing effects of the vaccine. Finally, we demonstrate for the first time the localization of human synthesized spike glycoprotein after the COVID-19 vaccine to the cutaneous and subcutaneous vasculature confirming the ability of SARS-CoV-2 spike glycoprotein to bind endothelium in the absence of intact virus.

Microvascular Skin Manifestations Caused by COVID-19

Hypercoagulability and vascular injury, which characterize morbidity in COVID-19 disease, are frequently observed in the skin. Several pathomechanisms, such as inflammation caused by angiotensin-converting enzyme 2-mediated uptake into endothelial cells or SARS-CoV-2-initiated host immune responses, contribute to microthrombus formation and the appearance of vascular skin lesions. Besides pathophysiologic mechanisms observed in the skin, this review describes the clinical appearance of cutaneous vascular lesions and their association with COVID-19 disease, including acro-ischemia, reticular lesions, and cutaneous small vessel vasculitis. Clinicians need to be aware that skin manifestations may be the only symptom in SARS-CoV-2 infection, and that inflammatory and thrombotic SARS-CoV-2-driven processes observed in multiple organs and tissues appear identically in the skin as well.

Chilblains during lockdown are associated with household exposure to SARS-CoV-2: a multicentre case-control study

Objectives

During the COVID-19 pandemic, numerous cases of chilblains have been reported. However, in most cases, RT-PCR or serology did not confirm SARS-CoV-2 infection. Hypotheses have been raised about an interferon-mediated immunological response to SARS-CoV-2, leading to effective clearance of the SARS-CoV-2 without the involvement of humoral immunity. Our objective was to explore the association between chilblains and exposure to SARS-CoV-2.

Methods

In this multicentre case–control study, cases were the 102 individuals referred to five referral hospitals for chilblains occurring during the first lockdown (March to May 2020). Controls were recruited from healthy volunteers' files held by the same hospitals. All members of their households were included, resulting in 77 case households (262 individuals) and 74 control households (230 individuals). Household exposure to SARS-CoV-2 during the first lockdown was categorized as high, intermediate or low, using a pre-established algorithm based on individual data on symptoms, high-risk contacts, activities outside the home and RT-PCR testing. Participants were offered a SARS-CoV-2 serological test.

Results

After adjustment for age, the association between chilblains and viral exposure was estimated at OR 3.3, 95% CI (1.4–7.3) for an intermediate household exposure, and 6.9 (2.5–19.5) for a high household exposure to SARS-CoV-2. Out of 57 case households tested, six (11%) had positive serology for SARS-CoV-2, whereas all control households tested (n = 50) were seronegative (p = 0.03). The effect of potential misclassification on exposure has been assessed in a bias analysis.

Discussion

This case–control study demonstrates the association between chilblains occurring during the lockdown and household exposure to SARS-CoV-2.

Pediatric Rheumatologic Effects of COVID-19

A multisystem inflammatory syndrome (MISC) can result from COVID-19 infection in previously healthy children and adolescents. It is potentially life threatening and is treated initially with intravenous immunoglobulin and aspirin but may require anti-inflammatory monoclonal antibody treatment in severe cases. SARS-CoV-2 infection can cause macrophage activation syndrome, chilblains, and flares of existing rheumatologic diseases. The pandemic has led to later presentation of some rheumatologic conditions as parents and patients have avoided health care settings. PubMed and Google scholar have been utilized to review the literature on the rheumatologic conditions resulting from COVID-19 and the current treatment options.

Dermatological Manifestations of COVID-19 in Patients Reporting to a Tertiary Care Hospital in Rawalpindi, Pakistan

Introduction The clinicopathological description of dermatological manifestations of COVID-19 leaves much to be desired. There is a need to determine their association with disease severity, outcome, and other clinical variables. Objectives The objectives of this study are to record and histopathologically examine the cutaneous manifestations of COVID-19 and correlate these to age, disease severity, and mortality. Methods All confirmed COVID-19 patients admitted to a single tertiary healthcare hospital in Rawalpindi, Pakistan, were included. Their diseases were classified as mild, moderate, severe, and critical. The recent onset skin eruptions in these patients were recorded via photographs along with relevant clinical data. The photographs were independently reviewed by a group of three dermatologists without knowledge of the clinical information. The skin manifestations were divided into disease-specific and nonspecific categories using an already defined algorithm. Histopathological examination of skin manifestations was conducted. Results A total of 23% (n=47) had "new" skin manifestations. Specific skin findings were seen in 21.6% (n=44), which consisted of ecchymosis/purpura in 50% (n=22), maculopapular exanthem in 18% (n=8), livedo reticularis in 16.2% (n=7), ischemia/gangrene in 16.2% (n=7), perniosis in 15.9 % (n=7), vesiculo-bullous rash in 9% (n=4) and urticaria in 4% (n=1). Non-specific findings were seen in 6% (n=13) and included bedsores, dermatitis passivata, dryness, herpes labialis, oral ulcerations, and nasogastric tube-induced ulcerations. There was a significant association (p=0.03) between disease severity and specific skin lesions. Ischemia/gangrene was significantly associated with COVID-19 disease severity and mortality. Vesiculobullous lesions were associated with higher mortality, though not with disease severity. Livedo reticularis had a higher-than-expected count in critical disease, albeit statistically insignificant. The association of maculopapular exanthem and ecchymosis/purpura with severe/critical disease was statistically insignificant. Urticaria was significantly associated with low disease severity. Mean age with specific manifestations was 56.86 ± 15.81 and with nonspecific/without any manifestations was 42.58 ± 16.96, a highly significant difference, with p-value < 0.001. Old age (>60 years) was significantly associated with ecchymosis (p=0.038), maculopapular exanthem (p=0.021), and vesiculo-bullous rash (p=0.029). Histopathology varied according to the type of skin lesion. Conclusions Dermatological manifestations coexist in many patients and tend to appear more in severe cases of COVID-19 among the older age group and only minimally in mild/moderate cases. Their presence could help set prognostic criteria of COVID-19 disease in the future.

[Cutaneous Manifestation of COVID-19: What have we learned an year into the pandemic?]

La enfermedad por coronavirus de 2019 (COVID-19) es una situación sanitaria emergente causada por el «síndrome respiratorio agudo severo por coronavirus 2» (SARS-CoV-2). La pandemia por COVID-19 en curso, que surgió de la ciudad china de Wuhan en diciembre de 2019, se ha propagado en 188 países, y ha infectado a más de 100 millones de personas a nivel mundial a lo largo de un año. Los síntomas más comunes de la COVID-19 incluyen fiebre y enfermedad respiratoria. Entre los signos extrapulmonares asociados a COVID-19 se han reportado cada vez más manifestaciones dermatológicas en las diferentes regiones geográficas. La incidencia o prevalencia exactas de las manifestaciones cutáneas asociadas a la COVID-19 son bastante desconocidas, y los mecanismos patofisiológicos siguen sin dilucidarse. En este artículo hemos tratado de aportar una visión general amplia de lo que hemos aprendido en un año de inmersión en la pandemia en cuanto a epidemiología y características clínicas e histopatológicas, mecanismos patofisiológicos y manejo clínico de las manifestaciones cutáneas asociadas a la COVID-19.

Are the chilblain-like lesions observed during the COVID-19 pandemic due to severe acute respiratory syndrome coronavirus 2? Systematic review and meta-analysis

The expansion of the COVID‐19 pandemic has been accompanied by numerous reports of chilblain‐like lesions (CLL) in different countries; however, the pathogenesis of these lesions is still unclear. This systematic review and meta‐analysis aimed to assess the prevalence of COVID‐19 (diagnosed using PCR and/or serology) in patients with CLL. We undertook a literature search in PubMed, Embase, and Scopus (to 15 March 2021), including studies that reported on the number of patients with CLL with positive PCR and/or serology for severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) or with a clinical suspicion of COVID‐19. Regardless of data heterogeneity, a random‐effects model was used to pool prevalence estimates. The meta‐analysis included 63 original studies, involving 2919 cases of CLL. A subgroup of these patients underwent diagnostic tests for COVID‐19 (PCR: n = 1154, 39.5%; serology: n = 943, 32.3%). The pooled prevalence of COVID‐19 in the overall sample and in the subgroup who were tested for COVID‐19 was, respectively: (i) positive PCR: 2.6% [95% confidence interval (CI) 1.9% to 3.4%] and 5.5% (95% CI, 3.7–7.7%); (ii) positive serology for SARS‐CoV‐2: 7.2% (95% CI, 4.7–10.2%) and 11.8% (95% CI, 7.9–16.3%); and (iii) positive PCR and/or serology, 15.2% (95% CI, 10.4–20.7%) and 7.5% (95% CI, 5.1–10.3%). Altogether, a small proportion of diagnostic tests for SARS‐CoV‐2, both PCR and serologies, show positive results in patients with CLL.

Clinicopathologic features between different viral epidemic outbreaks involving the skin

The current coronavirus disease 2019 pandemic has exceeded any epidemiologic prevision, but increasing information suggests some analogies with the major viral outbreaks of the last century. A general warning has been issued on the possibility that coinfections can make differential diagnosis and treatment difficult, especially in tropical countries. Some reports have pointed out that the presence of high Dengue antibodies can give a false-negative result for severe acute respiratory syndrome coronavirus 2. Mucocutaneous manifestations are very frequent, with an apparent overlap among different pathogens. A strong clinicopathologic correlation, however, may provide some clues to address the differential. Waiting for laboratory and instrumental results, the timing and distribution of skin lesions is often pathognomonic. Histopathologic findings characterize certain reaction patterns and provide insights on pathogenetic mechanisms. Unfortunately, skin assessments, especially invasive exams such as biopsy, are less important in severely ill patients. A literature review was performed to collect information from other epidemics to counteract what has become the most frightening disease of our time.

COVID toes: Pernio-like lesions

More than 40 million people have been infected with the severe acute respiratory syndrome coronavirus 2 since the first infection was reported in December 2019 from Wuhan, China. Multiple reports of cutaneous manifestations of the virus have been described, including a pernio-like eruption, recently termed “COVID toes.” We have reviewed the published case series on “COVID toes” in addition to studies identifying possible pathogenic mechanisms behind the eruption.

Long-term Outcome of Chilblains Associated with SARS-CoV-2

Numerous cases of chilblains have been observed in the course if the COVID-19 pandemic. The aims of this study were to provide comprehensive follow-up data for patients reporting chilblains, and to determine the risk factors for incomplete recovery. Patients referred to 5 hospitals in France between March and May 2020 for chilblains were surveyed on December 2020. A teleconsultation was offered. Among 82 patients reporting chilblains, 27 (33%) reported complete recovery, 33 (40%) had recurrences of chilblains after their hands and feet had returned to normal, and 22 (27%) developed persistent acral manifestations, mostly acrocyanosis, with or without further recurrences of chilblains. Most recurrences of chilblains occurred during the following autumn and winter. A past history of chilblains was not associated with recurrences or persistent acral manifestations. Women had a significantly higher risk of developing recurrences or persistent acral manifestations (odds ratio 1.30; 95% confidence interval 1.06–1.59). In conclusion, two-thirds of patients reporting chilblains at the start of the COVID-19 pandemic experienced persistent or recurrent acral manifestations after a 10-month follow-up.

COVID-19-related skin manifestations: Update on therapy

An increasing body of evidence has been produced in a very limited period to improve the understanding of skin involvement in the current coronavirus 2019 disease pandemic, and how this novel disease affects the management of dermatologic patients. A little explored area is represented by the therapeutic approach adopted for the different skin manifestations associated with the infection. An overview of the current scenario is provided, through review of the English-language literature published until October 30, 2020, and comparison with the personal experience of the authors. As dermatologists, our primary aim is to support patients with the highest standard of care and relieve suffering, even with lesions not life-threatening. With asymptomatic COVID-19 patients, patient discomfort related to skin lesions should not be undervalued and intervention to accelerate healing should be provided. Consensus protocols are warranted to assess the best skin-targeted treatments in COVID-19 patients.

DERMATOLOGY IN A MULTIDISCIPLINARY APPROACH WITH INFECTIOUS DISEASE AND OBSTETRIC MEDICINE AGAINST COVID-19

The care for patients infected with COVID-19 requires a team approach, and dermatologists may collaborate with other specialties, especially infectious disease (ID) medicine and obstetrics and gynecology (ObGyn), at every stage of the infection process. A broad spectrum of cutaneous manifestations may occur early in COVID-19 infection, making appropriate dermatologic identification critical for an early diagnosis. There is prognostic value in appropriately identifying different types of COVID-19–associated skin manifestations, which have been linked to disease severity. Such observations emanated from dermatology research, especially large series and international registries of cutaneous manifestations relating to COVID-19, and impact COVID-19 care provided by most health care providers. Also, research based on international registries of skin reactions from the COVID-19 vaccines has an impact across disciplines. An increased risk for severe illness from COVID-19 is encountered during pregnancy, and dermatologists’ role is to urge ObGyn and other clinicians to monitor and educate pregnant patients about the potential for eruptions as a manifestation of COVID-19. ID and ObGyn experts indicate that teledermatology enhanced the interaction among health care providers and improved COVID-19 care. More than 40% of all dermatology consultations at a tertiary care hospital were done via teledermatology. Future collaborative research involving dermatology and specialties, such as ID and ObGyn, could help delineate guidelines for dermatology consultations in patients infected with COVID-19 and determine cases appropriate for teledermatology.

Cutaneous eccrine inflammation and necrosis: review of inflammatory disorders affecting the eccrine apparatus including new associations

Despite being frequently overlooked during the examination of histopathological sections, eccrine sweat glands can offer clues for diagnosing various skin conditions. They provide important functions and can lead to several diseases when inflamed or injured. This review article provides information regarding eccrine physiology as well as well-established and novel entities that occur in association with eccrine gland pathology.

Synthesis of the Data on COVID-19 Skin Manifestations: Underlying Mechanisms and Potential Outcomes

The incidence of coronavirus disease 2019 (COVID-19)-related skin manifestations has progressively grown, in parallel with the global severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spreading. The available evidence indicates that cutaneous signs are heterogeneous and can be divided as follows: a) erythematous rashes, b) lesions of vascular origin, c) vesicular rashes, d) urticarial rashes, and e) acute generalized exanthematous pustulosis (AGEP), erythema multiforme (EM) and other polymorphic/atypical reactions. Most cutaneous manifestations appear simultaneously or after respiratory and/or systemic symptoms such as fever, even if rarely urticaria has been reported as the first sign of the disease. It has been proposed that erythematous and vesicular rashes, as well as urticaria, are the result of immunological activation against Sars-CoV-2, similarly to other viral exanthems; alternatively, reactivation or co-infection of herpesviruses and drug hypersensitivity represent possible etiologic diagnosis that has to be considered. Regarding lesions of vascular origin, ischemic ones are the result of systemic hypercoagulability established in severe infections, whereas chilblains seem to be linked to the type I-interferon massively produced to halt virus replication. AGEP is triggered by drugs, whereas EM could represent a delayed immune response to the virus or a hypersensitivity reaction to drugs elicited by the inflammatory process built to fight the infection. A further pathogenic hypothesis is that the virus, or its particles detected in the skin (particularly in endothelium and eccrine glands), could be responsible for certain skin reactions, including chilblains and EM. From the available data, it appears that chilblains are correlated with younger age and less severe disease, while ischemic manifestations occur in the elderly with severe infection. In conclusion, larger studies are needed to confirm the suggested pathogenetic mechanisms of COVID-19-related skin reactions and to determine the potential prognostic significance of each one.

Prognosis of rash and chilblain-like lesions among outpatients with COVID-19: a large cohort study

In a large regional observational cohort study of adult (≥ 18 years), outpatients with COVID-19, prevalence, characteristics, and outcome of patients with rash and/or chilblain-like lesions (CLL), compared with population without cutaneous features, were studied. In total, 28,957 outpatients were included; the prevalence of rash and CCL were 9.5% and 3.7%, respectively. Presence of rash was significantly associated with presence of asthenia, shivers or myalgia, respiratory and gastro-intestinal symptoms, and anosmia/ageusia. The presence of CCL was associated with chest pain, chest oppression, nausea/vomiting, and anosmia/ageusia. Patients with CCL were significantly less prone to an unfavourable outcome (hospitalization or death).

Skin lesions in children during the first wave of the SARS-CoV-2 pandemic

Background

Cutaneous manifestations have been included in COVID-19 patients’ clinical spectrum. Our objective was to determine the association between skin lesions in children and SARS-CoV2 infection, analyzing others possible infectious/autoimmune etiologies.

Material and methods

Observational, multicenter, cross-sectional study, about children with skin manifestations from April to May 2020. The diagnosis of SARS-CoV2 was performed by PCR in nasopharyngeal exudate and/or presence of antibodies by serology.

Results

Sixty-two children were included, 9 (14.5%) presented positive antibodies to SARS-CoV-2, with no positive PCR to SARS-Cov-2 in those patients in whom it was made. Patients with positive serology to SARS-CoV-2 presented chilblains and/or vesicular-bullous skin lesions more frequently (66.7% vs. 24.5%, p = 0.019). Generalized, urticarial and maculopapular rash was more common in patients with negative antibodies (37.7 vs. 0%, p = 0.047), others pathogens were isolated in 41.5% of these patients. There were no significant differences in the positivity for autoantibodies between both groups.

Conclusion

In our study, the presence of chilblains-like and/or vesicular lesions were significantly related to SARS-CoV2 previous contact.