Focus on "COVID Toes"

Pathobiology of Cutaneous Manifestations Associated with COVID-19 and Their Management

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing coronavirus disease 2019 (COVID-19) has been a rising concern since its declaration as a pandemic by the World Health Organization on 11 March 2020. Recently, its association with multiple underlying organs has been identified that includes cardiac, renal, gastrointestinal, nervous systems, and cutaneous manifestations. Cutaneous COVID-19 findings have been supposedly classified into the following categories: vesicular (varicella-like), papulo-vesiculsar, chilblains-like ("COVID toes") maculopapular, and urticarial morphologies. In this review, we aim to focus on the proposed pathophysiology behind the various dermatological manifestations associated with COVID-19 and their associated management. We also included prevalence and clinical features of the different COVID-19-related skin lesions in our review. A comprehensive narrative review of the literature was performed in PubMed databases. Data from case reports, observational studies, case series, and reviews till June 2022 were all screened and included in the review.

Multicenter analysis of neutrophil extracellular trap dysregulation in adult and pediatric COVID-19

Dysregulation in neutrophil extracellular trap (NET) formation and degradation may play a role in the pathogenesis and severity of COVID-19; however, its role in the pediatric manifestations of this disease, including multisystem inflammatory syndrome in children (MIS-C) and chilblain-like lesions (CLLs), otherwise known as “COVID toes,” remains unclear. Studying multinational cohorts, we found that, in CLLs, NETs were significantly increased in serum and skin. There was geographic variability in the prevalence of increased NETs in MIS-C, in association with disease severity. MIS-C and CLL serum samples displayed decreased NET degradation ability, in association with C1q and G-actin or anti-NET antibodies, respectively, but not with genetic variants of DNases. In adult COVID-19, persistent elevations in NETs after disease diagnosis were detected but did not occur in asymptomatic infection. COVID-19–affected adults displayed significant prevalence of impaired NET degradation, in association with anti-DNase1L3, G-actin, and specific disease manifestations, but not with genetic variants of DNases. NETs were detected in many organs of adult patients who died from COVID-19 complications. Infection with the Omicron variant was associated with decreased NET levels when compared with other SARS-CoV-2 strains. These data support a role for NETs in the pathogenesis and severity of COVID-19 in pediatric and adult patients.

Multicenter analysis of neutrophil extracellular trap dysregulation in adult and pediatric COVID-19

Dysregulation in neutrophil extracellular trap (NET) formation and degradation may play a role in the pathogenesis and severity of COVID-19; however, its role in the pediatric manifestations of this disease including MIS-C and chilblain-like lesions (CLL), otherwise known as "COVID toes", remains unclear. Studying multinational cohorts, we found that, in CLL, NETs were significantly increased in serum and skin. There was geographic variability in the prevalence of increased NETs in MIS-C, in association with disease severity. MIS-C and CLL serum samples displayed decreased NET degradation ability, in association with C1q and G-actin or anti-NET antibodies, respectively, but not with genetic variants of DNases. In adult COVID-19, persistent elevations in NETs post-disease diagnosis were detected but did not occur in asymptomatic infection. COVID-19-affected adults displayed significant prevalence of impaired NET degradation, in association with anti-DNase1L3, G-actin, and specific disease manifestations, but not with genetic variants of DNases. NETs were detected in many organs of adult patients who died from COVID-19 complications. Infection with the Omicron variant was associated with decreased levels of NETs when compared to other SARS-CoV-2 strains. These data support a role for NETs in the pathogenesis and severity of COVID-19 in pediatric and adult patients.

Summary

NET formation and degradation are dysregulated in pediatric and symptomatic adult patients with various complications of COVID-19, in association with disease severity. NET degradation impairments are multifactorial and associated with natural inhibitors of DNase 1, G-actin and anti-DNase1L3 and anti-NET antibodies. Infection with the Omicron variant is associated with decreased levels of NETs when compared to other SARS-CoV-2 strains.

Is Long COVID a State of Systemic Pericyte Disarray?

The most challenging aspect of Post-Acute Sequelae of SARS-CoV-2 Infection (PASC) or Long COVID remains for the discordance between the viral damage from acute infection in the recent past and susceptibility of Long COVID without clear evidence of post infectious inflammation or autoimmune reactions. In this communication we propose that disarray of pericytes plays a central role in emerge of Long COVID. We assume pericytes are agents with “Triple-A” qualities, i.e., analyze-adapt and advance, necessary for sustainability of host homeostasis. Based on this view, we further suggest Long COVID may provide a model system to integrate system theory and complex adaptive systems to explore a new class of maladies those are currently not well defined and with no remedies.

Nailfold capillaroscopy: A sensitive method for evaluating microvascular involvement in children with SARS-CoV-2 infection

OBJECTIVES

The hyperinflammatory state and the viral invasion may result in endothelial dysfunction in SARS-CoV-2 infection. Although a method foreseeing microvascular dysfunction has not been defined yet, studies conducted in patients diagnosed with COVID-19 have demonstrated the presence of endotheliitis. With this study, we aimed to investigate the microvascular circulation in patients diagnosed with COVID-19 and multisystem inflammatory syndrome in children (MIS-C) by nailfold videocapillaroscopy (NVC).

METHODS

Thirty-one patients with SARS-CoV-2 infection, 25 of whom were diagnosed with COVID-19 and 6 with MIS-C and 58 healthy peers were included in the study. NVC was performed in eight fingers with 2 images per finger and 16 images were examined for the morphology of capillaries, presence of pericapillary edema, microhemorrhage, avascular area, and neoangiogenesis. Capillary length, capillary width, apical loop, arterial and venous width, and intercapillary distance were measured from three consecutive capillaries from the ring finger of the non-dominant hand.

RESULTS

COVID-19 patients showed significantly more capillary ramification (p < 0.001), capillary meandering (p = 0.04), microhemorrhage (p < 0.001), neoangiogenesis (p < 0.001), capillary tortuosity (p = 0.003). Capillary density (p = 0.002) and capillary length (p = 0.002) were significantly lower in the patient group while intercapillary distance (p = 0.01) was significantly longer compared with healthy volunteers. Morphologically, patients with MIS-C had a higher frequency of capillary ramification and neoangiogenesis compared with COVID-19 patients (p = 0.04).

CONCLUSION

Abnormal capillary alterations seen in COVID-19 and MIS-C patients indicate both similar and different aspects of these two spectra of SARS-CoV-2 infection and NVC appears to be a simple and non-invasive method for evaluation of microvascular involvement.

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.

A Review of COVID-19 Chilblains-like Lesions and Their Differential Diagnoses

GENERAL PURPOSE

To familiarize wound care practitioners with the differential diagnoses of chilblains-like lesions that could be associated with the complications of COVID-19.

TARGET AUDIENCE

This continuing education activity is intended for physicians, physician assistants, nurse practitioners, and nurses with an interest in skin and wound care.

LEARNING OBJECTIVES/OUTCOMES

After participating in this educational activity, the participant will:1. Identify the population most often affected by COVID toes.2. Select the assessments that help differentiate the various conditions that cause chilblains-like lesions.3. Choose appropriate treatment options for the various conditions that cause chilblains-like lesions.

From cellular function to global impact: the vascular perspective on COVID-19

Since COVID-19 was declared a pandemic a year ago, our understanding of its effects on the vascular system has slowly evolved. At the cellular level, SARS-CoV-2 - the virus that causes COVID-19 - accesses the vascular endothelium through the angiotensin-converting enzyme 2 (ACE-2) receptor and induces proinflammatory and prothrombotic responses. At the clinical level, these pathways lead to thromboembolic events that affect the pulmonary, extracranial, mesenteric, and lower extremity vessels. At the population level, the presence of vascular risk factors predisposes individuals to more severe forms of COVID-19, whereas the absence of vascular risk factors does not spare patients with COVID-19 from unprecedented rates of stroke, pulmonary embolism and acute limb ischemia. Finally, at the community and global level, the fear of COVID-19, measures taken to limit the spread of SARS-CoV-2 and reallocation of limited hospital resources have led to delayed presentations of severe forms of ischemia, surgery cancellations and missed opportunities for limb salvage. The purpose of this narrative review is to present some of the data on COVID-19, from cellular mechanisms to clinical manifestations, and discuss its impact on the local and global surgical communities from a vascular perspective.

SARS-CoV-2-related MIS-C: A key to the viral and genetic causes of Kawasaki disease?

Multisystem inflammatory syndrome in children (MIS-C) emerged in April 2020 in communities with high COVID-19 rates. This new condition is heterogenous but resembles Kawasaki disease (KD), a well-known but poorly understood and clinically heterogenous pediatric inflammatory condition for which weak associations have been found with a myriad of viral illnesses. Epidemiological data clearly indicate that SARS-CoV-2 is the trigger for MIS-C, which typically occurs about 1 mo after infection. These findings support the hypothesis of viral triggers for the various forms of classic KD. We further suggest that rare inborn errors of immunity (IEIs) altering the immune response to SARS-CoV-2 may underlie the pathogenesis of MIS-C in some children. The discovery of monogenic IEIs underlying MIS-C would shed light on its pathogenesis, paving the way for a new genetic approach to classic KD, revisited as a heterogeneous collection of IEIs to viruses.

ST-segment elevation myocardial infarction in post-COVID-19 patients: A case series

Coronavirus disease 2019 (COVID-19) is associated with an increased risk of thromboembolic events in the acute setting. However, the abnormal thrombotic diathesis is not known to persist into the recovery phase of COVID-19 infection. We described 3 cases of ST-segment elevation myocardial infarction in healthy male patients who recovered from COVID-19 with no prior cardiovascular risk factors. They shared features of elevated von Willebrand factor antigen, factor VIII and D-dimer level. One patient had a borderline positive lupus anticoagulant. Intravascular ultrasound of culprit vessels revealed predominantly fibrotic plaque with minimal necrotic core. Clot waveform analysis showed parameters of hypercoagulability. They were treated with dual antiplatelet therapy, angiotensin-converting-enzyme inhibitor, beta blocker and statin. These cases highlight the strong thrombogenic nature of COVID-19 that persisted among patients who recovered from infection. Several suspected mechanisms could explain the association between vascular thrombosis in the convalescent period (endothelial dysfunction, hypercoagulability, systemic inflammatory response and vasculopathy). Additional studies on "long COVID" are essential for identifying endotheliopathy and thrombotic sequalae.

The Impact of COVID-19 on Vascular Surgery Practice: A Systematic Review

BACKGROUND

COVID-19 is characterized by a pulmonary interstitial compromise which can require intensive care unit (ICU) and mechanical ventilation. Covid patients develop a wide range of pathologies. This study aims to identify the impact of COVID-19 in diseases commonly treated by vascular surgeons.

METHODS

Four conditions were selected: venous thromboembolism (VTE), pulmonary embolism (PE), peripheral arterial disease (PAD), and microangiopathy. A systematic review of the literature using PRISMA guidelines was.

RESULTS

Out of 1195 papers reviewed for conditions in COVID-19 patients relevant to routine vascular surgery practice, 43 papers were included and analyzed. Venous thrombosis was found to be the most common COVID-19 associated pathology with a cumulative incidence of 25% at 7 days and 48% at 14 days. Additionally, D-dimer levels proved to be a good predictor, even in the early stages of the disease with a sensitivity of 85%, specificity of 88.5% and a negative predictive value of 94.7%. Patients in the ICU demonstrated a significantly higher risk of developing VTE, even when receiving pharmacologic thromboprophylaxis. Although evidence of arterial thrombosis was less common (1% to 16.3%), its consequences were typically more serious, including limb loss and death even in young individuals (OR = 25, 95% CI). Finally, microangiopathy has a wide spectrum of clinical presentations from retinal microangiopathy to other more severe manifestations such as myocardial injury, pulmonary compromise and potential multiple organ dysfunction syndrome.

CONCLUSIONS

Although the pathophysiological pathway by which COVID-19 produces thrombosis is not completely clear, the incidence of both arterial and venous thrombosis is increased. D-dimer screening should be done in all COVID-19 patients, as a predictor of thrombotic complications.

Proposal of the Definition for COVID-19-Associated Coagulopathy

Thrombotic events are common complications in COVID-19 patients that include both thrombus formation in large vessels and the microvasculature of the lung and other organs. COVID-19-associated coagulopathy (CAC) and disseminated intravascular coagulation (DIC) have similarities and differences, and whether CAC is a form of DIC is the subject of debate. Reported mechanisms of CAC include activated coagulation, endotheliopathy, up-regulated innate and adaptive immunity, and activated complement system. Although the clinical features and laboratory findings of CAC and DIC seem different, there are fundamental similarities that should be considered. Basically, the pathological findings of COVID-19 fall within the scope of the definition of DIC, i.e., systemic activation of coagulation caused by or resulting from the microvascular damage. Therefore, we suggest that although CAC differs from usual infection-associated DIC, its various features indicate that it can be considered a thrombotic phenotype DIC. This review summarizes the current knowledge about CAC including differences and similarities with sepsis-associated DIC.

COVID-19: The experience from Iran

The first cases of coronavirus disease 2019 (COVID-19) in Iran were detected on February 19, 2020. Soon the entire country was hit with the virus. Although dermatologists were not immediately the frontline health care workers, all aspects of their practice were drastically affected. Adapting to this unprecedented crisis required urgent appropriate responses. With preventive measures and conserving health care resources being the most essential priorities, dermatologists, as an integral part of the health system, needed to adapt their practices according to the latest guidelines. The spectrum of the challenges encompassed education, teledermatology, lasers, and other dermatologic procedures, as well as management of patients who were immunosuppressed or developed drug reactions and, most importantly, the newly revealed cutaneous signs of COVID-19. These challenges have paved the way for new horizons in dermatology.

Multisystem Inflammatory Syndrome in Children (MIS-C), a Post-viral Myocarditis and Systemic Vasculitis-A Critical Review of Its Pathogenesis and Treatment

MIS-C is a newly defined post-viral myocarditis and inflammatory vasculopathy of children following COVID-19 infection. This review summarizes the literature on diagnosis, parameters of disease severity, and current treatment regimens. The clinical perspective was analyzed in light of potential immunopathogenesis and compared to other post-infectious and inflammatory illnesses of children affecting the heart. In this paradigm, the evidence supports the importance of endothelial injury and activation of the IL-1 pathway as a common determinant among MIS-C, Kawasaki disease, and Acute Rheumatic fever.

Type I Interferon Signature in Chilblain-Like Lesions Associated with the COVID-19 Pandemic

Contemporarily to the new SARS-CoV-2 mediated COVID-19 pandemic, a rise in patients with acral chilblain lesions has been described. They manifest late after mild disease or asymptomatic exposure to SARS-CoV-2. Their pathogenic evolution is currently unknown. In biopsies from three patients with acral partially ulcerating chilblain lesions that occurred associated to the COVID-19 pandemic, we analysed the expression of type I interferon induced proteins and signal transduction kinases. Histology demonstrated perivascular and periadnexal lymphohistiocytic infiltrates and endothelial dominated MxA-staining, as well as pJAK1 activation. Our findings demonstrate induction of the type I IFN pathway in lesional sections of COVID-19-associated chilblain-like lesions. This may indicate a local antiviral immune activation status associated with preceding exposure to SARS-CoV-2.

Changes in Primary Care Visits in the 24 Weeks After COVID-19 Stay-at-Home Orders Relative to the Comparable Time Period in 2019 in Metropolitan Chicago and Northern Illinois

OBJECTIVE

In this brief report, we characterize pediatric primary care service utilization in metropolitan Chicago over the first 24 weeks of the COVID-19 pandemic response in relation to the comparable time period in 2019.

METHODS

We examined retrospective visit and billing data, regardless of payer, from 16 independent pediatric practices that utilize a common electronic medical record platform within an Accountable Care Organization of 252 pediatricians in 71 offices throughout metropolitan Chicago. We categorized visits as Well-Child and Immunization-Only (WC-IO) or Other types and identified visits with a telemedicine billing modifier. Diagnoses for Other visits were tallied and categorized using the Agency for Healthcare Research and Quality Clinical Classification System. We summarized counts of visits and the proportion of visits with a telemedicine billing modifier in one-week epochs for 2020 compared with 2019.

RESULTS

There were 102 942 total visits (72 030 WC-IO; 30 912 Other) in 2020 and 144 672 visits (80 578 WC-IO; 64 094 Other) in 2019. WC-IO visits in 2020 were half of 2019 visits at the start of the Illinois Stay-at-Home Order and returned greater than 90% of 2019 visits in 8 weeks. Other visit types have remained below 70% of 2019 visits. A telemedicine billing modifier peaked in mid-April (21% of all visits) and declined to <10% of all visits in June (Phase 2 reopening). The top 10 most common diagnoses differed between years.

CONCLUSIONS

Recovery of well child and immunization visits suggests that practice-level efforts and policy change can ensure children receive recommended care as the pandemic evolves.

An Immediate and Long-Term Complication of COVID-19 May Be Type 2 Diabetes Mellitus: The Central Role of β-Cell Dysfunction, Apoptosis and Exploration of Possible Mechanisms

The novel coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) was declared a pandemic by the WHO on 19 March 2020. This pandemic is associated with markedly elevated blood glucose levels and a remarkable degree of insulin resistance, which suggests pancreatic islet β-cell dysfunction or apoptosis and insulin's inability to dispose of glucose into cellular tissues. Diabetes is known to be one of the top pre-existing co-morbidities associated with the severity of COVID-19 along with hypertension, cardiocerebrovascular disease, advanced age, male gender, and recently obesity. This review focuses on how COVID-19 may be responsible for the accelerated development of type 2 diabetes mellitus (T2DM) as one of its acute and suspected long-term complications. These observations implicate an active role of metabolic syndrome, systemic and tissue islet renin-angiotensin-aldosterone system, redox stress, inflammation, islet fibrosis, amyloid deposition along with β-cell dysfunction and apoptosis in those who develop T2DM. Utilizing light and electron microscopy in preclinical rodent models and human islets may help to better understand how COVID-19 accelerates islet and β-cell injury and remodeling to result in the long-term complications of T2DM.