Lessons from dermatology about inflammatory responses in Covid-19

Neutrophil heterogeneity and aging: implications for COVID-19 and wound healing

Neutrophils play a critical role in the immune response to infection and tissue injury. However, recent studies have shown that neutrophils are a heterogeneous population with distinct subtypes that differ in their functional properties. Moreover, aging can alter neutrophil function and exacerbate immune dysregulation. In this review, we discuss the concept of neutrophil heterogeneity and how it may be affected by aging. We then examine the implications of neutrophil heterogeneity and aging for COVID-19 pathogenesis and wound healing. Specifically, we summarize the evidence for neutrophil involvement in COVID-19 and the potential mechanisms underlying neutrophil recruitment and activation in this disease. We also review the literature on the role of neutrophils in the wound healing process and how aging and neutrophil heterogeneity may impact wound healing outcomes. Finally, we discuss the potential for neutrophil-targeted therapies to improve clinical outcomes in COVID-19 and wound healing.

Granuloma annulare after SARS-CoV-2 vaccination: A case report and a literature review

INTRODUCTION

During the Cov-19 pandemic, many studies reported a broad spectrum of cutaneous reactions presenting as erythematous rashes or pernio-like, urticaria-like or vesicular/bullous patterns associated with Cov-19-infection and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination.

METHODS

The authors documented the clinical and histopathological features of an unexpected case of granuloma annulare (GA) arising a few days after the SARS-CoV-2 vaccination and reviewed all GAs reported in the literature following the SARS-CoV-2 vaccination and Cov-19-infection.

CASE REPORT

A 69-year-old woman developed a single reddish lesion on the left deltoid region, where the SARS-CoV-2 vaccine seven days earlier was injected. The clinicians performed a punch skin biopsy, and histology revealed an interstitial GA.

CONCLUSIONS

Clinicians should be aware of the potential, though rare, GA occurrence as a possible adverse event after the SARS-CoV-2 vaccination. This additional case, like what happens after the administration of other vaccines, supports the idea that GA may result from the immune system activation following the vaccination. However, notwithstanding, they should encourage their patients to obtain immunization to assist the public health systems in overcoming the COVID-19 pandemic.

Skin manifestations in patients with COVID-19: a prospective observational study during the first wave of the pandemic in the UK and review of the recent literature

Background

COVID-19 (SARS-CoV-2) is a viral infection that presents in heterogeneous forms with effects on multiple organ systems including the skin.

Objectives

The objectives of this prospective observational study were to identify cutaneous lesions in confirmed COVID-19-positive patients admitted to a district general hospital in the eastern region of England, to determine the prevalence of these lesions and compare the findings with the current literature.

Materials & Methods

The study was conducted at the Luton and Dunstable University Hospital during the first peak of the pandemic in the United Kingdom to identify skin manifestations in patients infected with COVID-19. Several variables were taken into consideration and photographs of skin lesions were taken. Unlike previous similar studies, all patients included in this study had a positive nasopharyngeal PCR swab for SARS-CoV-2. All photographs were analysed by a dermatology consultant.

Results

A total of 93 patients were included in the study; 40% (n = 37) had cutaneous lesions but only 5.5% of the total patients (n = 6) presented with likely coronavirus-related skin changes. Lesions identified were pseudochilblain and purpuric/livedoid type. We also noted several coagulation abnormalities in these patients.

Conclusion

COVID-19 can present with a variety of skin manifestations. Pseudochilblain lesions and purpuric livedoid lesions have been described in the literature and although the underlying mechanism is not fully understood, it is possible that these lesions represent thromboinflammatory processes as a result of the hypercoagulability state associated with COVID-19. More research is required to better understand the pathophysiology and epidemiology of these manifestations.

Supplementary data

Supplementary data associated with this article can be found, in the online version, at doi: 10.1684/ejd.2022.4202.

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.

A bird's eye view on the role of dendritic cells in SARS-CoV-2 infection: Perspectives for immune-based vaccines

Coronavirus disease-19 (COVID-19) is a complex disorder caused by the pandemic diffusion of a novel coronavirus named SARS-CoV-2. Clinical manifestations vary from silent infection to severe pneumonia, disseminated thrombosis, multi-organ failure, and death. COVID-19 pathogenesis is still not fully elucidated, while increasing evidence suggests that disease phenotypes are strongly related to the virus-induced immune system's dysregulation. Indeed, when the virus-host cross talk is out of control, the occurrence of an aberrant systemic inflammatory reaction, named "cytokine storm," leads to a detrimental impairment of the adaptive immune response. Dendritic cells (DCs) are the most potent antigen-presenting cells able to support innate immune and promote adaptive responses. Besides, DCs play a key role in the anti-viral defense. The aim of this review is to focus on DC involvement in SARS-CoV-2 infection to better understand pathogenesis and clinical behavior of COVID-19 and explore potential implications for immune-based therapy strategies.

Skin manifestations associated with COVID-19

This article will address the main aspects of skin manifestations associated with COVID-19, based on a review of the literature published to date. Since the beginning of the pandemic, more than 1,500 articles have been published on the subject. Regarding the pathophysiology, it is believed that the same mechanisms responsible for the disease in the main target organs also act in the skin, although they are not yet fully elucidated. The actual frequency of dermatological manifestations remains uncertain – it can range from 0.2% to 45%, being close to 6% in systematic reviews. Pioneering studies of large case series conducted in European countries and the USA provide the first information on the main skin manifestations associated with COVID-19 and propose classifications regarding their clinical presentation, pathophysiology, as well as their frequencies. Although there is yet no consensus, maculopapular eruptions are considered the most frequent presentations, followed by erythema pernio-like (EPL) lesions. Manifestations such as urticaria, vesicular conditions and livedo/purpura/necrosis are rare. The time of onset, severity, need for specific treatment and prognosis vary according to the clinical presentation pattern. The increasing histopathological description of skin conditions can contribute to the diagnosis, as well as to the understanding of the pathophysiology. Also, in the dermatological field, the relationship between COVID-19 and androgens has been increasingly studied. Despite all the generated knowledge, the actual biological meaning of skin manifestations remains uncertain. Therefore, the exclusion of the main differential diagnoses is essential for the correlation between skin manifestation and COVID-19.

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.

Characterization and structural basis of a lethal mouse-adapted SARS-CoV-2

There is an urgent need for animal models to study SARS-CoV-2 pathogenicity. Here, we generate and characterize a novel mouse-adapted SARS-CoV-2 strain, MASCp36, that causes severe respiratory symptoms, and mortality. Our model exhibits age- and gender-related mortality akin to severe COVID-19. Deep sequencing identified three amino acid substitutions, N501Y, Q493H, and K417N, at the receptor binding domain (RBD) of MASCp36, during in vivo passaging. All three RBD mutations significantly enhance binding affinity to its endogenous receptor, ACE2. Cryo-electron microscopy analysis of human ACE2 (hACE2), or mouse ACE2 (mACE2), in complex with the RBD of MASCp36, at 3.1 to 3.7 Å resolution, reveals the molecular basis for the receptor-binding switch. N501Y and Q493H enhance the binding affinity to hACE2, whereas triple mutations at N501Y/Q493H/K417N decrease affinity and reduce infectivity of MASCp36. Our study provides a platform for studying SARS-CoV-2 pathogenesis, and unveils the molecular mechanism for its rapid adaptation and evolution.

Characterization and structural basis of a lethal mouse-adapted SARS-CoV-2

There is an urgent need for animal models to study SARS-CoV-2 pathogenicity. Here, we generate and characterize a novel mouse-adapted SARS-CoV-2 strain, MASCp36, that causes severe respiratory symptoms, and mortality. Our model exhibits age- and gender-related mortality akin to severe COVID-19. Deep sequencing identified three amino acid substitutions, N501Y, Q493H, and K417N, at the receptor binding domain (RBD) of MASCp36, during in vivo passaging. All three RBD mutations significantly enhance binding affinity to its endogenous receptor, ACE2. Cryo-electron microscopy analysis of human ACE2 (hACE2), or mouse ACE2 (mACE2), in complex with the RBD of MASCp36, at 3.1 to 3.7 Å resolution, reveals the molecular basis for the receptor-binding switch. N501Y and Q493H enhance the binding affinity to hACE2, whereas triple mutations at N501Y/Q493H/K417N decrease affinity and reduce infectivity of MASCp36. Our study provides a platform for studying SARS-CoV-2 pathogenesis, and unveils the molecular mechanism for its rapid adaptation and evolution.

In this study, Qin et al. present a murine-adapted SARS-CoV-2 strain, MASCp36, as a model for studying the pathogenicity, evolution and adaptation of the virus to human and animal hosts.

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.

The Role of Dermatologists in the Early HIV/AIDS Epidemic: A Historical Review for the 40th Anniversary of HIV/AIDS

In 1981, the HIV/AIDS epidemic was first recognized in young gay men presenting with opportunistic infections and Kaposi sarcoma. Over the past 40 years, there has been an unparalleled and hugely successful effort on the part of physicians, scientists, public health experts, community activists, and grassroots organizations to study, treat, and prevent HIV/AIDS. Yet the role of dermatologists in the investigation of HIV/AIDS and in the treatment of infected patients has largely been neglected in the historical literature. It is important to revisit dermatologists' historic contributions and problematic biases during this epidemic and honor the legacy of the dermatologists who were instrumental in treating and advocating for patients affected by HIV/AIDS.

Virology and Etiopathogenesis of COVID-19 with Special Reference to Cutaneous Implications

Severe Acute Respiratory Virus Corona Virus 2 (SARS-CoV-2) has got its name Corona from Latin meaning “crown.” It has crown-like spikes present on the surface, which encloses the RNA, genetic material of this deadly virus. The virus attacks pneumocytes after binding with the angiotensin-converting enzyme 2 (ACE2) of the cell surface, which ultimately leads to chemotaxis followed by leukocyte infiltration, increased permeability of blood vessels and alveolar walls, and decreased surfactant in the lung leading to various symptoms. Skin provides a window to the internal changes of the body and also to mechanisms that are not readily visible. Commonly observed skin manifestations include vesicular lesions, maculopapular exanthema, urticarial eruptions, livedo or necrosis, and other forms of vasculitis, chilblain-like lesions. The skin lesions are attributed to either the virus directly affecting the skin or interferon dysregulation due to viral RNA or vascular involvement associated with alteration in coagulation or drug-induced skin manifestations. Observation of skin involvement and the vasculature due to SARS-CoV-2 illustrates the need for a precise stratification and differential diagnostic valuation so that the mechanisms of this novel virus are clearer for better management of the condition in the future. Vascular skin lesions are not seen in all the patients of COVID, but certain lesions should definitely alarm us to evaluate for coagulation abnormalities, complement levels, and skin biopsy, especially in critically ill patients. This review attempts to outline the pathogen briefly and the pathomechanism behind the development of various cutaneous manifestations.

Potential Misdiagnosis between COVID-19 and Dengue Infection Using Rapid Serological Test

The coronavirus disease 2019 (COVID-19) pandemic that has a significant rapid transmission is an international public health concern. Several dengue-endemic countries reported similar clinical and laboratory features between COVID-19 and dengue in the early incubation period, and thus discerning the infection is difficult. As a dengue-endemic country, Indonesia also poses the same challenge during the COVID-19 outbreak. This current study analyzed the IgG and IgM profiles from COVID-19 patients by using a serological SARS-CoV-2 and dengue rapid test. In addition, 38 sera from healthy individuals (pre-COVID-19 date) were analyzed using a dengue rapid test. Among 120 samples, 4 samples indicated dengue IgG positive. However, IgM, NS1, and RT-PCR analyses showed negative results. Interestingly, regarding seropositivity of NS1 and DENV IgG from healthy individuals (pre COVID-19 infection), two samples were positive DENV IgG, while one of them was positive NS1. This suggested that in the dengue-endemic area, many people have already experienced dengue and have immunity against dengue virus. There is also the possibility of antibody cross-reactivity between COVID-19 and dengue infection. This also emphasizes the high demand for a rapid method with high sensitivity and specificity that can distinguish between SARS-CoV-2 and dengue.

Identification of SARS-CoV-2-induced pathways reveals drug repurposing strategies

The global outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) necessitates the rapid development of new therapies against coronavirus disease 2019 (COVID-19) infection. Here, we present the identification of 200 approved drugs, appropriate for repurposing against COVID-19. We constructed a SARS-CoV-2-induced protein network, based on disease signatures defined by COVID-19 multiomics datasets, and cross-examined these pathways against approved drugs. This analysis identified 200 drugs predicted to target SARS-CoV-2-induced pathways, 40 of which are already in COVID-19 clinical trials, testifying to the validity of the approach. Using artificial neural network analysis, we classified these 200 drugs into nine distinct pathways, within two overarching mechanisms of action (MoAs): viral replication (126) and immune response (74). Two drugs (proguanil and sulfasalazine) implicated in viral replication were shown to inhibit replication in cell assays. This unbiased and validated analysis opens new avenues for the rapid repurposing of approved drugs into clinical trials.

Prominent Cutaneous Manifestation of COVID-19: A Case Report

Extrapulmonary signs of coronavirus disease are becoming an important tool for patient diagnosis; this is particularly true for skin manifestations as they are visible to both the patient and physician. In this case report, the authors describe a case in which cutaneous manifestations were the most noticeable and prominent symptom in a patient with coronavirus disease.

Clinicopathologic correlations of COVID-19-related cutaneous manifestations with special emphasis on histopathologic patterns

Skin is one of target organs affected by the novel coronavirus SARS-CoV-2, and in response to the current COVID-19 pandemic, a fast body of literature has emerged on related cutaneous manifestations. Current perspective is that the skin is not only a bystander of the general cytokines storm with thrombophilic multiorgan injury, but it is directly affected by the epithelial tropism of the virus, as confirmed by the detection of SARS-CoV-2 in endothelial cells and epithelial cells of epidermis and eccrine glands. In contrast with the abundance of epidemiologic and clinical reports, histopathologic characterization of skin manifestations is limited. Without an adequate clinicopathologic correlation, nosology of clinically similar conditions is confusing, and effective association with COVID-19 remains presumptive. Several patients with different types of skin lesions, including the most specific acral chilblains-like lesions, showed negative results at SARS-CoV-2 nasopharyngeal and serologic sampling. The aim of this review is to provide an overview of what has currently been reported worldwide, with a particular emphasis on microscopic patterns of the skin manifestations in patients exposed to or affected by COVID-19. Substantial breakthroughs may occur in the near future from more skin biopsies, improvement of immunohistochemistry studies, RNA detection of SARS-CoV-2 strain by real-time polymerase chain reaction-based assay, and electron microscopic studies.

Skin manifestations of COVID-19: A worldwide review

Objective

Because of the increasing emergence of skin manifestations of COVID-19 worldwide, we investigated the published reports of these lesions.

Methods

We conducted a literature search for original and review articles published from November 11, 2019 to September 30, 2020.

Results

We identified 5 skin lesions common in patients with COVID-19: pseudo-chilblains, rashes containing macules and papules, and urticarial, vesicular, and vaso-occlusive lesions. These lesions manifested at various times in relation to the COVID-19 symptoms, which may indicate whether the lesions are virus-induced or are delayed immunological responses to the infection. Skin lesions were more prevalent among Europeans and United States residents than among Asians, as was pseudo-chilblain, and the morphology of the skin lesions varied among continents. Pseudo-chilblains were the most common COVID-19 skin manifestation in Europe and the United States, but there was only 1 reported case from Asian populations. Additionally, patients with vaso-occlusive lesions were more likely than those with pseudo-chilblains to be admitted to the intensive care unit and to die.

Conclusion

Different cutaneous manifestations in patients with COVID-19 could reflect a wide spectrum of viral interactions with the skin, though reporting bias may play a role as well.

Serological cross-reaction and coinfection of dengue and COVID-19 in Asia: Experience from Indonesia

Similar symptoms and laboratory findings between dengue and coronavirus disease 2019 (COVID-19) pose a diagnostic challenge in some dengue-endemic countries in Asia. In this study, we reported three cases of suspected COVID-19-dengue coinfection in hospitals of Bali, Indonesia. Serological data demonstrated that patients with positive results for dengue virus (DENV) NS1 antigen and anti-dengue IgM were also reactive to COVID-19 rapid antibody tests, suggesting dengue-COVID-19 coinfection. However, two patients were later confirmed negative for SARS-COV-2 by qRT-PCR, implying a plausible cross-reactivity of anti-dengue and anti-COVID-19 antibodies in the serological test. Coinfection of dengue and COVID-19 was evident in one patient, following confirmation of SARS-COV-2 by qRT-PCR and DENV infection using the NS1 antigen serology test. This case was the first case of dengue and COVID-19 coinfection in Indonesia and revealed possible cross-reactivity between SARS-COV-2 and DENV antibodies based on rapid serological tests. Our study indicates a public health concern regarding COVID-19 and dengue detection in Indonesia as well as in other dengue-endemic countries, and it is important for these nations to manage both pathogens concurrently.

Projected supportive effects of PycnogenolⓇ in patients suffering from multi-dimensional health impairments after a SARS-CoV2 infection

Corona virus disease 2019 (COVID-19) is triggered by the Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV2) and has rapidly developed into a worldwide pandemic. Unlike other SARS viruses, SARS-CoV2 does not solely impact the respiratory system, but additionally leads to inflammation of endothelial cells, microvascular injuries and coagulopathies, thereby affecting multiple organs. Recent reports of patients who were infected with SARS-CoV2 suggest persistent health problems even months after the initial infection. The French maritime pine bark extract Pycnogenol^Ⓡ has demonstrated anti-inflammatory, vascular and endothelium-protective effects in over 90 human clinical studies. It is proposed that Pycnogenol^Ⓡ may be beneficial in supporting recovery and mitigating symptoms and long-term consequences resulting from a SARS-CoV2 infection in COVID-19 patients.

Lessons from dermatology about inflammatory responses in Covid-19

The SARS‐Cov‐2 is a single‐stranded RNA virus composed of 16 non‐structural proteins (NSP 1‐16) with specific roles in the replication of coronaviruses. NSP3 has the property to block host innate immune response and to promote cytokine expression. NSP5 can inhibit interferon (IFN) signalling and NSP16 prevents MAD5 recognition, depressing the innate immunity. Dendritic cells, monocytes, and macrophages are the first cell lineage against viruses' infections. The IFN type I is the danger signal for the human body during this clinical setting. Protective immune responses to viral infection are initiated by innate immune sensors that survey extracellular and intracellular space for foreign nucleic acids. In Covid‐19 the pathogenesis is not yet fully understood, but viral and host factors seem to play a key role. Important points in severe Covid‐19 are characterized by an upregulated innate immune response, hypercoagulopathy state, pulmonary tissue damage, neurological and/or gastrointestinal tract involvement, and fatal outcome in severe cases of macrophage activation syndrome, which produce a ‘cytokine storm’. These systemic conditions share polymorphous cutaneous lesions where innate immune system is involved in the histopathological findings with acute respiratory distress syndrome, hypercoagulability, hyperferritinemia, increased serum levels of D‐dimer, lactic dehydrogenase, reactive‐C‐protein and serum A amyloid. It is described that several polymorphous cutaneous lesions similar to erythema pernio, urticarial rashes, diffuse or disseminated erythema, livedo racemosa, blue toe syndrome, retiform purpura, vesicles lesions, and purpuric exanthema or exanthema with clinical aspects of symmetrical drug‐related intertriginous and flexural exanthema. This review describes the complexity of Covid‐19, its pathophysiological and clinical aspects.