The differing pathophysiologies that underlie COVID-19-associated perniosis and thrombotic retiform purpura: a case series

Diagnosis and management of COVID toes in outpatients: a case report

BACKGROUND

Since the beginning of the coronavirus disease 2019 pandemic, the most common skin lesions observed due to infection with the severe acute respiratory syndrome coronavirus 2 are pseudochilblains (or coronavirus disease toes). However, this pathology remains infrequent and difficult to diagnose, as no specific test exists.

CASE PRESENTATION

Two Caucasian women, 30 and 22 years old, presented to our General Medicine Unit with perniosis lesions on the feet during the first two waves of the coronavirus disease 2019 pandemic. They did not have respiratory or general symptoms of severe acute respiratory syndrome coronavirus 2 infection, the reverse transcription polymerase chain reaction on nasopharyngeal swabs was negative, and the serology was positive only in the first case. The clinical presentation differed for the two cases, as the second patient suffered from swelling and burning after cold application. The diagnosis was based on clinical presentation, temporality, exclusion of other differential diagnoses, and blood test results (positive serology in the first case and high level of CXCL13 and VEGF in the second), supported by current literature. Lesions resolved spontaneously in the first patient. The second case was hospitalized for pain management and received corticosteroid therapy with resolution of the symptoms.

CONCLUSION

These two cases with different clinical presentations illustrate the diagnostic approach to coronavirus disease 2019, a challenging disease with diverse manifestations, including, in some cases, coronavirus disease toes. We present a literature review that illustrates the progression of scientific research. Skin lesions associated with coronavirus disease 2019 infection could be the expression of an important interferon type 1 response and should be considered in the differential diagnosis in a primary care setting.

Emerging role of complement in COVID-19 and other respiratory virus diseases

The complement system, a key component of innate immunity, provides the first line of defense against bacterial infection; however, the COVID-19 pandemic has revealed that it may also engender severe complications in the context of viral respiratory disease. Here, we review the mechanisms of complement activation and regulation and explore their roles in both protecting against infection and exacerbating disease. We discuss emerging evidence related to complement-targeted therapeutics in COVID-19 and compare the role of the complement in other respiratory viral diseases like influenza and respiratory syncytial virus. We review recent mechanistic studies and animal models that can be used for further investigation. Novel knockout studies are proposed to better understand the nuances of the activation of the complement system in respiratory viral diseases.

Microvascular C5b-9 deposition in non-lesional skin in patients with SLE and its correlation with active lupus nephritis: a prospective observational study

OBJECTIVE

Tissue damage in lupus nephritis (LN) is mediated by activation of the classical complement pathway. Complement-mediated upregulation of endothelial cell adhesion molecules is seen in dermal blood vessels of non-lesional skin of patients with active lupus. In diseases with systemic complement activation, extensive microvascular C5b-9 deposition is seen in non-lesional skin. In this study, we assess the presence of systemic complement pathway activation as determined by non-lesional skin microvascular C5b-9 deposition in patients with LN.

METHODS

Eight patients with active LN and eight patients without active LN underwent non-lesional skin biopsies. Using a diaminobenzidine technique, specimens were evaluated for microvascular C5b-9 consistent with systemic complement pathway activation.

RESULTS

Five of eight patients with active LN and one of eight patients without active LN demonstrated positive C5b-9 staining in non-lesional skin (p=0.04). Positive non-lesional C5b-9 staining has greater specificity, 87.5%, for active LN than pyuria, low complements, elevated double-stranded DNA (dsDNA) and proteinuria. Urine protein creatinine ratio was significantly higher in patients with positive non-lesional C5b-9 deposition (5.18 vs 1.20; p=0.04). C5b-9 deposition was not associated with a higher NIH Activity Index, interstitial fibrosis, dsDNA or lower complements.

CONCLUSION

This is the first study to demonstrate evidence in non-lesional skin of microvascular C5b-9 indicative of systemic complement pathway activation in LN. C5b-9 deposition is statistically more common and demonstrated greater specificity than most historical biomarkers for active LN. The findings support a potential role for microvascular C5b-9 assessment in non-lesional skin as a biomarker for LN activity.

Part II: Cutaneous manifestations of peripheral vascular disease

In this Part 2 of a 2-part continuing medical education series, we review the epidemiology of peripheral vascular disease, its association with cutaneous symptoms, and the diagnosis and evaluation of cutaneous features of vascular disorders. As peripheral vascular disease becomes more prevalent globally, it is essential for dermatologists to become competent at accurately recognizing and diagnosing cutaneous manifestations and directing individuals to receive appropriate care and treatment.

COVID 19-associated chilblain-like acral lesions among children and adolescents: an Italian retrospective, multicenter study

BACKGROUND

Since the COVID-19 pandemic started, great interest has been given to this disease, especially to its possible clinical presentations. Besides classical respiratory symptoms, dermatological manifestations occur quite often among infected and non-infected patients, particularly in children. A prominent IFN-I response, that is generally higher in children compared to adults, may not only cause chilblain lesions, but it could also prevent infection and viral replication, thus justifying the negative swab results, as well as the absence of relevant systemic symptoms in positive cases. Indeed, reports have emerged describing chilblain-like acral lesions in children and adolescents with either proven or suspected infection.

METHODS

Patients aged from 1 to 18 years old were enrolled in this study from 23 Italian dermatological units and were observed for an overall period of 6 months. Clinical pictures were collected along with data on the location and duration of skin lesions, their association with concomitant local and systemic symptoms, presence of nail and/or mucosal involvement, as well as histological, laboratory and imaging findings.

RESULTS

One hundred thirty-seven patients were included, of whom 56.9% were females. Mean age was 11.97±3.66 years. The most commonly affected sites were the feet (77 patients, 56.2%). Lesions (48.5%) featured cyanosis, chilblains, blisters, ecchymosis, bullae, erythema, edema, and papules. Concomitant skin manifestations included maculo-papular rashes (30%), unspecified rashes (25%), vesicular rashes (20%), erythema multiforme (10%), urticaria (10%) and erythema with desquamation (5%). Forty-one patients (29.9%) reported pruritus as the main symptom associated with chilblains, and 56 out of 137 patients also reported systemic symptoms such as respiratory symptoms (33.9%), fever (28%), intestinal (27%), headache (5.5%), asthenia (3.5%), and joint pain (2%). Associated comorbid conditions were observed in 9 patients presenting with skin lesions. Nasopharyngeal swabs turned out positive in 11 patients (8%), whereas the remainder were either negative (101, 73%) or unspecified (25, 18%).

CONCLUSIONS

COVID-19 has been credited as the etiology of the recent increase in acro-ischemic lesions. The present study provides a description of pediatric cutaneous manifestations deemed to be potentially associated with COVID-19, revealing a possible association between acral cyanosis and nasopharyngeal swab positivity in children and teenagers. The identification and characterization of newly recognized patterns of skin involvement may aid physicians in diagnosing cases of asymptomatic or pauci-symptomatic COVID patients.

Abnormal thrombosis and neutrophil activation increase hospital-acquired sacral pressure injuries and morbidity in COVID-19 patients

Hospitalized patients have an increased risk of developing hospital-acquired sacral pressure injury (HASPI). However, it is unknown whether SARS-CoV-2 infection affects HASPI development. To explore the role of SARS-CoV-2 infection in HASPI development, we conducted a single institution, multi-hospital, retrospective study of all patients hospitalized for ≥5 days from March 1, 2020 to December 31, 2020. Patient demographics, hospitalization information, ulcer characteristics, and 30-day-related morbidity were collected for all patients with HASPIs, and intact skin was collected from HASPI borders in a patient subset. We determined the incidence, disease course, and short-term morbidity of HASPIs in COVID-19(+) patients, and characterized the skin histopathology and tissue gene signatures associated with HASPIs in COVID-19 disease. COVID-19(+) patients had a 63% increased HASPI incidence rate, HASPIs of more severe ulcer stage (OR 2.0, p<0.001), and HASPIs more likely to require debridement (OR 3.1, p=0.04) compared to COVID-19(-) patients. Furthermore, COVID-19(+) patients with HASPIs had 2.2x increased odds of a more severe hospitalization course compared to COVID-19(+) patients without HASPIs. HASPI skin histology from COVID-19(+) patients predominantly showed thrombotic vasculopathy, with the number of thrombosed vessels being significantly greater than HASPIs from COVID-19(-) patients. Transcriptional signatures of a COVID-19(+) sample subset were enriched for innate immune responses, thrombosis, and neutrophil activation genes. Overall, our results suggest that immunologic dysregulation secondary to SARS-CoV-2 infection, including neutrophil dysfunction and abnormal thrombosis, may play a pathogenic role in development of HASPIs in patients with severe COVID-19.

Chilblain-Like Lesions (CLL) Coinciding With the SARS-CoV-2 Pandemic in Children: A Systematic Review

Chilblain-like lesions (CLL) coinciding with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection have been described in the literature. Available reviews of the literature suggest that CLL are associated with younger age, an equal sex ratio, negative testing for SARS-CoV-2, and mild to no extracutaneous manifestations (ECM) associated with COVID-19 infection. This systematic review aims to provide a summary of reports of CLL associated with the early SARS-CoV-2 pandemic in children to clarify the prevalence, clinical characteristics, and resolution outcomes of these skin findings. Sixty-nine studies, published between May 2020 and January 2022, met inclusion criteria and were summarized in this review, representing 1,119 cases of CLL. Available data showed a slight male predominance (591/1002, 59%). Mean age was 13 years, ranging from 0 to 18 years. Most cases had no ECM (682/978, 70%). Overall, 70/507 (14%) of patients tested positive for COVID-19 using PCR and/or serology. In the majority the clinical course was benign with 355/415 (86%) of cases resolving, and 97/269 (36%) resolving without any treatment. This comprehensive summary of pediatric CLL suggests these lesions are rarely associated with COVID-19 symptoms or test positivity.

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.

Complement activation in COVID-19 and targeted therapeutic options: A scoping review

Increasing evidence suggests that activation of the complement system plays a key role in the pathogenesis and disease severity of Coronavirus disease 2019 (COVID-19). We used a systematic approach to create an overview of complement activation in COVID-19 based on histopathological, preclinical, multiomics, observational and clinical interventional studies. A total of 1801 articles from PubMed, EMBASE and Cochrane was screened of which 157 articles were included in this scoping review. Histopathological, preclinical, multiomics and observational studies showed apparent complement activation through all three complement pathways and a correlation with disease severity and mortality. The complement system was targeted at different levels in COVID-19, of which C5 and C5a inhibition seem most promising. Adequately powered, double blind RCTs are necessary in order to further investigate the effect of targeting the complement system in COVID-19.

Levamisole-induced and COVID-19-induced retiform purpura: two overlapping, emerging clinical syndromes

Levamisole exposure in cocaine users is a well-recognized cause of retiform purpura, a distinctive net-like maculopapular patch. Prolonged exposure to levamisole can lead to a serious systemic syndrome known as levamisole-induced vasculitis, most commonly involving the kidneys and lungs. More recently, retiform purpura has been observed in patients with the novel coronavirus disease of 2019 (COVID-19). Due to their overlapping dermatologic and systemic manifestations, levamisole-induced and COVID-19-induced retiform purpura may mimic one another in clinical presentation. The possibility that patients may present with one or both syndromes creates a diagnostic challenge. This review of levamisole-induced and COVID-19-induced retiform purpura highlights their corresponding and distinctive features. Additionally, we propose a unique staging system for levamisole-induced retiform purpura that may be valid for future classification of COVID-19-induced retiform purpura.

The relationship of skin disorders, COVID-19, and the therapeutic potential of ginseng: a review

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has made significant impacts on global public health, including the development of several skin diseases that have arisen primarily as a result of the pandemic. Owing to the widespread expansion of coronavirus disease 19 (COVID-19), the development of effective treatments for these skin diseases is drawing attention as an important social issue. For many centuries, ginseng and its major active ingredients, ginsenosides and saponins, have been widely regarded as herbal medicines. Further, the anti-viral action of ginseng suggests its potential effectiveness as a therapeutic agent against COVID-19. Thus, the aim of this review was to examine the association of skin lesions with COVID-19 and the effect of ginseng as a therapeutic agent to treat skin diseases induced by COVID-19 infection. We classified COVID-19-related skin disorders into three categories: caused by inflammatory, immune, and complex (both inflammatory and immune) responses and evaluated the evidence for ginseng as a treatment for each category. This review offers comprehensive evidence on the improvement of skin disorders induced by SARS-CoV-2 infection using ginseng and its active constituents.

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.

Premortem Skin Biopsy Assessing Microthrombi, Interferon Type I Antiviral and Regulatory Proteins, and Complement Deposition Correlates with Coronavirus Disease 2019 Clinical Stage

Apart from autopsy, tissue correlates of coronavirus disease 2019 (COVID-19) clinical stage are lacking. In the current study, cutaneous punch biopsy specimens of 15 individuals with severe/critical COVID-19 and six with mild/moderate COVID-19 were examined. Evidence for arterial and venous microthrombi, deposition of C5b-9 and MASP2 (representative of alternative and lectin complement pathways, respectively), and differential expression of interferon type I-driven antiviral protein MxA (myxovirus resistance A) versus SIN3A, a promoter of interferon type I-based proinflammatory signaling, were assessed. Control subjects included nine patients with sepsis-related acute respiratory distress syndrome (ARDS) and/or acute kidney injury (AKI) pre-COVID-19. Microthrombi were detected in 13 (87%) of 15 patients with severe/critical COVID-19 versus zero of six patients with mild/moderate COVID-19 (P < 0.001) and none of the nine patients with pre-COVID-19 ARDS/AKI (P < 0.001). Cells lining the microvasculature staining for spike protein of severe acute respiratory syndrome coronavirus 2, the etiologic agent of COVID-19, also expressed tissue factor. C5b-9 deposition occurred in 13 (87%) of 15 patients with severe/critical COVID-19 versus zero of six patients with mild/moderate COVID-19 (P < 0.001) and none of the nine patients with pre-COVID-19 ARDS/AKI (P < 0.001). MASP2 deposition was also restricted to severe/critical COVID-19 cases. MxA expression occurred in all six mild/moderate versus two (15%) of 13 severe/critical cases (P < 0.001) of COVID-19. In contrast, SIN3A was restricted to severe/critical COVID-19 cases co-localizing with severe acute respiratory syndrome coronavirus 2 spike protein. SIN3A was also elevated in plasma of patients with severe/critical COVID-19 versus control subjects (P ≤ 0.02). In conclusion, the study identified premortem tissue correlates of COVID-19 clinical stage using skin. If validated in a longitudinal cohort, this approach could identify individuals at risk for disease progression and enable targeted interventions.

Long COVID endotheliopathy: hypothesized mechanisms and potential therapeutic approaches

SARS-CoV-2-infected individuals may suffer a multi-organ system disorder known as "long COVID" or post-acute sequelae of SARS-CoV-2 infection (PASC). There are no standard treatments, the pathophysiology is unknown, and incidence varies by clinical phenotype. Acute COVID-19 correlates with biomarkers of systemic inflammation, hypercoagulability, and comorbidities that are less prominent in PASC. Macrovessel thrombosis, a hallmark of acute COVID-19, is less frequent in PASC. Female sex at birth is associated with reduced risk for acute COVID-19 progression, but with increased risk of PASC. Persistent microvascular endotheliopathy associated with cryptic SARS-CoV-2 tissue reservoirs has been implicated in PASC pathology. Autoantibodies, localized inflammation, and reactivation of latent pathogens may also be involved, potentially leading to microvascular thrombosis, as documented in multiple PASC tissues. Diagnostic assays illuminating possible therapeutic targets are discussed.

Osteomyelitis of the Jaw in COVID-19 Patients: A Rare Condition With a High Risk for Severe Complications

Osteomyelitis of the jaw is an uncommon infection that arises from the flora of the oral cavity or sinuses and affects immunocompromised and polymorbid patients. Treatment includes surgical debridement and long regiments of broad-spectrum antibiotics. We present three cases of complicated jaw osteomyelitis presented with concurrent COVID-19 infection, including only two reported cases of odontogenic COVID-related osteomyelitis. The two mandibular cases were patients in their 30s with no comorbidities. The first case was an asymptomatic COVID-19-positive patient who developed an odontogenic infection after tooth extraction that was complicated by the second bout of abscess formation and localized osteomyelitis. The second case was a COVID-19-positive patient with an odontogenic infection that presented as airway compromise due to trismus and neck edema, which required an emergency tracheotomy. He developed osteomyelitis of the mandibular ramus that was reconstructed with a titanium plate. The third case was a polymorbid post-COVID-19 patient who developed a protracted infection of the maxillary sinus that resulted in the loss of an eye, destruction of the maxilla, palate, and parts of nasal cavum, and oronasal incontinence. The defect was reconstructed with a microvascular anterolateral thigh flap. We hypothesize that COVID-19-related immune dysfunction and microvascular changes contributed to osteomyelitis in our patients.

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.

A curious case of ‘COVID toes’ in pregnancy

The novel coronavirus of 2019 (COVID-19) can affect multiple organ systems with a wide spectrum of illness severity. Its effect on the respiratory tract is well-documented and has resulted in considerable excess mortality worldwide. However, observed cutaneous manifestations of COVID-19 are rising, ranging from short-lived viral exanthems to vesicular eruptions and urticaria. An unusual subgroup of these manifestations – pseudo-chilblains, also referred to as pernio-like lesions or ‘COVID toes’ – describes the acral areas of erythema and oedema that can affect young individuals following COVID-19. We present a case associated with pustule and vesicle formation occurring in the context of pregnancy.

[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.

Insights into urticaria in pediatric and adult populations and its management with fexofenadine hydrochloride

OBJECTIVE

The present narrative review provides a comprehensive update of the current knowledge on urticaria, both in adult and pediatric populations, and on the safety and efficacy of fexofenadine hydrochloride (HCl) as a treatment option.

DATA SOURCE

A literature search was conducted on Embase and Medline.

STUDY SELECTION

Clinical studies published in English and published between 1999 and 2020 were selected.

RESULTS

Although the exact pathogenesis of urticaria is not fully understood, multiple pathways of mast cell activation are discussed to explain the existence of phenotypically different clinical manifestations of urticaria. An overview of the worldwide prevalence of chronic urticaria, including disease burden and patient's quality of life is provided. The impact of urticaria on patient's life differs on the basis of whether its form is acute or chronic, but pharmacological approaches are most often needed to control the disabling symptoms. A summary of the current management of urticaria recommended by different guidelines across countries (Global; European; American; Australian; Asian; Japanese) is presented. Non-sedating, second-generation H₁-antihistamines are the preferred choice of treatment across several guidelines worldwide. Herein, the efficacy and safety of fexofenadine HCl, a representative second-generation H₁-antihistamine approved for the treatment of urticaria, is discussed. The occurrence of urticaria manifestations in COVID-19 patients is also briefly presented.

CONCLUSION

The burden of acute and chronic urticaria is high for patients. Second generation anti-histamines such as fexofenadine HCl can help managing the symptoms.

Case Report: Idiopathic Subcutaneous Thrombotic Vasculopathy

Lower extremity ulcers have significant morbidity, with treatment determined by the underlying disorder. Reported is a 32-year-old female presenting with small skin nodules and bruises across her legs 4 weeks following her second COVID vaccination. These lesions progressed into large, necrotic ulcers over several months. Initial work-up showed widespread pannicular thrombotic vasculopathy with ischemic skin necrosis. The tissue was negative for calcification on Von Kossa histochemistry, and a working diagnosis of subcutaneous thrombotic vasculopathy was suggested. The ulcers progressed despite treatments with corticosteroids, therapeutic anticoagulation, intravenous immunoglobulin, plasmapheresis, sodium thiosulfate, wound care, and repeat debridement. Later debridement specimens demonstrated rare vascular and pannicular calcifications. This finding supports the hypothesis that subcutaneous thrombotic vasculopathy is a precursor to calciphylaxis, the patient’s current working diagnosis. However, based on the patient’s entire clinical picture, a definitive diagnosis has yet to be found. This report highlights the challenges of working with rare diseases and the importance of multidisciplinary cooperation.

COVID-19 Vasculitis and vasculopathy-Distinct immunopathology emerging from the close juxtaposition of Type II Pneumocytes and Pulmonary Endothelial Cells

The SARS-CoV-2 virus ACE-2 receptor utilization for cellular entry and the defined ACE-2 receptor role in cardiovascular medicine hinted at dysregulated endothelial function or even direct viral endotheliitis as the key driver of severe COVID-19 vascular immunopathology including reports of vasculitis. In this article, we critically review COVID-19 immunopathology from the vasculitis perspective and highlight the non-infectious nature of vascular endothelial involvement in severe COVID-19. Whilst COVID-19 lung disease pathological changes included juxta-capillary and vascular macrophage and lymphocytic infiltration typical of vasculitis, we review the evidence reflecting that such “vasculitis” reflects an extension of pneumonic inflammatory pathology to encompass these thin-walled vessels. Definitive, extrapulmonary clinically discernible vasculitis including cutaneous and cardiac vasculitis also emerged- namely a dysregulated interferon expression or “COVID toes” and an ill-defined systemic Kawasaki-like disease. These two latter genuine vasculitis pathologies were not associated with severe COVID-19 pneumonia. This was distinct from cutaneous vasculitis in severe COVID-19 that demonstrated pauci-immune infiltrates and prominent immunothrombosis that appears to represent a novel immunothrombotic vasculitis mimic contributed to by RNAaemia or potentially diffuse pulmonary venous tree thrombosis with systemic embolization with small arteriolar territory occlusion, although the latter remains unproven. Herein, we also performed a systematic literature review of COVID-19 vasculitis and reports of post-SARS-CoV-2 vaccination related vasculitis with respect to the commonly classified pre-COVID vasculitis groupings. Across the vasculitis spectrum, we noted that Goodpasture’s syndrome was rarely linked to natural SARS-CoV-2 infection but not vaccines. Both the genuine vasculitis in the COVID-19 era and the proposed vasculitis mimic should advance the understanding of both pulmonary and systemic vascular immunopathology.

Dermatological Manifestations of COVID-19 in Children

Context

The clinical picture of pediatric severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) infection differs from adults as do the cutaneous manifestations. In this review, we summarize the varied morphological manifestations of SARS-CoV-2 infection in the pediatric population.

Evidence acquisition

A comprehensive literature search was conducted (23 September, 2021) across multiple databases (PubMed, EMBASE, MEDLINE and Cochrane) with the relevant keywords. An additional filter of age group between 0–18 years was kept in each of the searches.

Results

Chilblains constitute the most common cutaneous manifestation of pediatric coronavirus disease (COVID-19). Other commonly reported manifestations include maculopapular rash, urticaria, erythema multiforme, and papulovesicular eruptions. Majority of children with these manifestations are asymptomatic, highlighting the need to clinically suspect and appropriately manage such patients. A subset of pediatric patients develop severe multisystem involvement termed as multi-system inflammatory syndrome in children (MIS-C) that has varied mucocutaneous manifestations.

Conclusion

A wide variety of dermatological manifestation of SARS-CoV-2 infection is reported, and both the pediatrician and dermatologist need to be aware of the same to suspect and diagnose COVID-19 infection in children.

Electronic Supplementary Material

Supplementary material is available in the online version of this article at 10.1007/s13312-022-2521-6.

A Deadly Embrace: Hemagglutination Mediated by SARS-CoV-2 Spike Protein at Its 22 N-Glycosylation Sites, Red Blood Cell Surface Sialoglycoproteins, and Antibody

Rouleaux (stacked clumps) of red blood cells (RBCs) observed in the blood of COVID-19 patients in three studies call attention to the properties of several enveloped virus strains dating back to seminal findings of the 1940s. For COVID-19, key such properties are: (1) SARS-CoV-2 binds to RBCs in vitro and also in the blood of COVID-19 patients; (2) although ACE2 is its target for viral fusion and replication, SARS-CoV-2 initially attaches to sialic acid (SA) terminal moieties on host cell membranes via glycans on its spike protein; (3) certain enveloped viruses express hemagglutinin esterase (HE), an enzyme that releases these glycan-mediated bindings to host cells, which is expressed among betacoronaviruses in the common cold strains but not the virulent strains, SARS-CoV, SARS-CoV-2 and MERS. The arrangement and chemical composition of the glycans at the 22 N-glycosylation sites of SARS-CoV-2 spike protein and those at the sialoglycoprotein coating of RBCs allow exploration of specifics as to how virally induced RBC clumping may form. The in vitro and clinical testing of these possibilities can be sharpened by the incorporation of an existing anti-COVID-19 therapeutic that has been found in silico to competitively bind to multiple glycans on SARS-CoV-2 spike protein.

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.

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.

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.

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.

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.

Cutaneous Pathology of COVID-19 as a Window into Immunologic Mechanisms of Disease

Many skin manifestations of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection reflect activation of cutaneous and systemic immune responses involving effector pathways of both the innate and adaptive arms of the immune system. This article reviews evidence from the recent clinical and scientific literature that informs the current understanding of the consequences of coronavirus disease 2019 (COVID-19)-induced immune cell activation, as relevant to dermatology. Topics include the clinical consequences of autoantibody production in patients with COVID-19, immunologic evidence for chilblains as a manifestation of SARS-CoV-2 infection, and the relationship between type I interferons and COVID-19 disease severity.

Clinical Patterns and Morphology of COVID-19 Dermatology

Coronavirus disease 2019 (COVID-19), an emergent disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has rapidly spread throughout the globe since its discovery in December 2019. Although first appreciated to cause pneumonia, numerous organ systems are now known to be involved. The objective of this article is to review the broad spectrum of cutaneous manifestations reported in association with SARS-CoV-2 infection. The most commonly reported cutaneous manifestations associated with COVID-19 infection include pernio (chilblain)-like acral lesions, morbilliform (exanthematous) rash, urticaria, vesicular (varicella-like) eruptions, and vaso-occlusive lesions (livedo racemosa, retiform purpura). It is important to consider SARS-CoV-2 infection in the differential diagnosis of a patient presenting with these lesions in the appropriate clinical context, as cutaneous manifestations may be present in otherwise asymptomatic individuals, or present before developing other symptoms of infection. With increased access to diagnostic testing, we are beginning to understand the utility and limitations of currently available assays.

Cutaneous manifestations in children with SARS-CoV-2 infection and/or COVID-19: what do we know after 10 months under this pandemic?

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global crisis. However, cutaneous manifestations in children with SARS-CoV-2 infection have received little attention.

OBJECTIVE

Our study was aimed to present clinical and cutaneous manifestations of children with SARS-CoV-2 and to provide the basis for early diagnosis.

METHODS

We analyzed the clinical data of COVID-19 infected (CI) children worldwide from December 2019 to October 6, 2020, by using search terms "COVID-19," "SARS-CoV-2," "Coronavirus" in combination with "cutaneous," "lesion," "rash," "skin," "dermatology," "epidermis," "dermis," "multisystem inflammatory syndrome." We collected and analyzed the general information, clinical symptoms, cutaneous manifestations, laboratory examination results, history of close contact with CI patients or suspected CI patients, and outcome in CI children.

RESULTS

Among 90 CI children, there were 46 boys (59%) and 32 girls (41%). Erythema was the most frequent lesion, followed by conjunctivitis, and edematous lesions. Face was the most commonly affected location including lips, conjunctivae, tongue, eyes, and eyelids. Sixty-three (73.3%) patients had multisystem inflammatory syndrome (MIS-C). As for clinical symptoms, 70 (81.4%) CI children suffered fever, and 34 (39.5%) patients had lung involvement. Meanwhile, 65.1% of patients had cardiac involvement, 4.7% of patients were asymptomatic, and 71.6% of patients received intravenous immunoglobulin, as well as 31.1% of CI children received systemic corticosteroids. Three children were dead. The most frequent route of infection was familial clustering. As silent virus carriers of CI children, it is important to find out the clinical and cutaneous manifestations in CI children to prevent and control COVID-19 transmission.

COVID-19-specific skin changes related to SARS-CoV-2: Visualizing a monumental public health challenge

The novel coronavirus SARS-CoV-2 has caused coronavirus disease-2019, known as COVID-19, now a pandemic stressing millions of individuals worldwide. COVID-19 is a systemic respiratory infection that may have dermatologic signs and systemic sequelae, a devastating public health challenge with parallels to the two great influenza pandemics of the last century. Skin lesions linked with COVID-19 have been grouped into six categories, with three distinct indicative patterns: vesicular (varicella-like), vasculopathic, and chilblains-like (including “COVID toes” and “COVID fingers”) plus the following three less suggestive patterns: dermatitic, maculopapular, and urticarial morphologies. Vasculopathic changes are the most concerning, in some patients, reflecting a devastating blood clotting dysfunction. We discuss the ways to detect, prevent, and treat COVID-19, keeping in mind the context of possible cutaneous markers of COVID-19 to enhance detection.

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.

A clinicopathological description of COVID-19-induced chilblains (COVID-toes) correlated with a published literature review

Background

The abundance of publications of COVID‐19‐induced chilblains has resulted in a confusing situation.

Methods

This is a prospective single‐institution study from 15 March to 13 May 2020. Thirty‐two patients received PCR nasopharyngeal swabs. Of these, 28 patients had a thoracic CT‐scan, 31 patients had blood and urine examinations, 24 patients had skin biopsies including immunohistochemical and direct immunofluorescence studies, and four patients had electron microscopy.

Results

COVID‐19‐induced chilblains are clinically and histopathologically identical to chilblains from other causes. Although intravascular thrombi are sometimes observed, no patient had a systemic coagulopathy or severe clinical course. The exhaustive clinical, radiological, and laboratory work‐up in this study ruled‐out other primary and secondary causes. Electron microscopy revealed rare, probable viral particles whose core and spikes measured from 120 to 133 nm within endothelium and eccrine glands in two cases.

Conclusion

This study provides further clinicopathologic evidence of COVID‐19‐related chilblains. Negative PCR and antibody tests do not rule‐out infection. Chilblains represent a good prognosis, occurring later in the disease course. No systemic coagulopathy was identified in any patient. Patients presenting with acral lesions should be isolated, and chilblains should be distinguished from thrombotic lesions (livedo racemosa, retiform purpura, or ischemic acral necrosis).

Skeletal Muscle and Peripheral Nerve Histopathology in COVID-19

OBJECTIVE

To explore the spectrum of skeletal muscle and nerve pathology of patients who died after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and to assess for direct viral invasion of these tissues.

METHODS

Psoas muscle and femoral nerve sampled from 35 consecutive autopsies of patients who died after SARS-CoV-2 infection and 10 SARS-CoV-2-negative controls were examined under light microscopy. Clinical and laboratory data were obtained by chart review.

RESULTS

In SARS-CoV-2-positive patients, mean age at death was 67.8 years (range 43-96 years), and the duration of symptom onset to death ranged from 1 to 49 days. Four patients had neuromuscular symptoms. Peak creatine kinase was elevated in 74% (mean 959 U/L, range 29-8,413 U/L). Muscle showed type 2 atrophy in 32 patients, necrotizing myopathy in 9, and myositis in 7. Neuritis was seen in 9. Major histocompatibility complex-1 (MHC-1) expression was observed in all cases of necrotizing myopathy and myositis and in 8 additional patients. Abnormal expression of myxovirus resistance protein A (MxA) was present on capillaries in muscle in 9 patients and in nerve in 7 patients. SARS-CoV-2 immunohistochemistry was negative in muscle and nerve in all patients. In the 10 controls, muscle showed type 2 atrophy in all patients, necrotic muscle fibers in 1, MHC-1 expression in nonnecrotic/nonregenerating fibers in 3, MxA expression on capillaries in 2, and inflammatory cells in none, and nerves showed no inflammatory cells or MxA expression.

CONCLUSIONS

Muscle and nerve tissue demonstrated inflammatory/immune-mediated damage likely related to release of cytokines. There was no evidence of direct SARS-CoV-2 invasion of these tissues.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that muscle and nerve biopsies document a variety of pathologic changes in patients dying of coronavirus disease 2019 (COVID-19).

Systemic and organ-specific immune-related manifestations of COVID-19

Immune-related manifestations are increasingly recognized conditions in patients with COVID-19, with around 3,000 cases reported worldwide comprising more than 70 different systemic and organ-specific disorders. Although the inflammation caused by SARS-CoV-2 infection is predominantly centred on the respiratory system, some patients can develop an abnormal inflammatory reaction involving extrapulmonary tissues. The signs and symptoms associated with this excessive immune response are very diverse and can resemble some autoimmune or inflammatory diseases, with the clinical phenotype that is seemingly influenced by epidemiological factors such as age, sex or ethnicity. The severity of the manifestations is also very varied, ranging from benign and self-limiting features to life-threatening systemic syndromes. Little is known about the pathogenesis of these manifestations, and some tend to emerge within the first 2 weeks of SARS-CoV-2 infection, whereas others tend to appear in a late post-infectious stage or even in asymptomatic patients. As the body of evidence comprises predominantly case series and uncontrolled studies, diagnostic and therapeutic decision-making is unsurprisingly often based on the scarcely reported experience and expert opinion. Additional studies are required to learn about the mechanisms involved in the development of these manifestations and apply that knowledge to achieve early diagnosis and the most suitable therapy.

Bilateral Chilblain-like Lesions of the Toes Characterized by Microvascular Remodeling in Adolescents During the COVID-19 Pandemic

IMPORTANCE

Chilblain-like lesions have been one of the most frequently described cutaneous manifestations during the COVID-19 pandemic. Their etiopathogenesis, including the role of SARS-CoV-2, remains elusive.

OBJECTIVE

To examine the association of chilblain-like lesions with SARS-CoV-2 infection.

DESIGN, SETTING, AND PARTICIPANTS

This prospective case series enrolled 17 adolescents who presented with chilblain-like lesions from April 1 to June 30, 2020, at a tertiary referral academic hospital in Italy.

MAIN OUTCOMES AND MEASURES

Macroscopic (clinical and dermoscopic) and microscopic (histopathologic) analysis contributed to a thorough understanding of the lesions. Nasopharyngeal swab, serologic testing, and in situ hybridization of the skin biopsy specimens were performed to test for SARS-CoV-2 infection. Laboratory tests explored signs of systemic inflammation or thrombophilia. Structural changes in peripheral microcirculation were investigated by capillaroscopy.

RESULTS

Of the 17 adolescents (9 [52.9%] male; median [interquartile range] age, 13.2 [12.5-14.3] years) enrolled during the first wave of the COVID-19 pandemic, 16 (94.1%) had bilaterally localized distal erythematous or cyanotic lesions. A triad of red dots (16 [100%]), white rosettes (11 [68.8%]), and white streaks (10 [62.5%]) characterized the dermoscopic picture. Histologic analysis revealed a remodeling of the dermal blood vessels with a lobular arrangement, wall thickening, and a mild perivascular lymphocytic infiltrate. SARS-CoV-2 infection was excluded by molecular and serologic testing. In situ hybridization did not highlight the viral genome in the lesions.

CONCLUSIONS AND RELEVANCE

This study delineated the clinical, histologic, and laboratory features of chilblain-like lesions that emerged during the COVID-19 pandemic, and its findings do not support their association with SARS-CoV-2 infection. The lesions occurred in otherwise healthy adolescents, had a long but benign course to self-resolution, and were characterized by a microvascular remodeling with perivascular lymphocytic infiltrate but no other signs of vasculitis. These results suggest that chilblain-like lesions do not imply a concomitant SARS-CoV-2 infection. Ongoing studies will help clarify the etiopathogenic mechanisms.

Development of sacral/buttock retiform purpura as an ominous presenting sign of COVID-19 and clinical and histopathologic evolution during severe disease course

Retiform purpura has been described as a relatively frequent cutaneous finding in patients with coronavirus disease 2019 (COVID-19). The etiology is hypothesized to be related to thrombotic vasculopathy based on lesional biopsy specimen findings, but the pathogenesis of the vasculopathy is not completely understood. Here, we present a case of a retiform purpuric patch on the sacrum/buttocks in a hospitalized patient prior to subsequent diagnosis of COVID-19 and an eventual fatal disease course. Two lesional biopsy specimens at different time points in the disease course revealed thrombotic vasculopathy, despite therapeutic anticoagulation. Detailed histopathologic evaluation using immunohistochemical markers suggest the etiology of the vasculopathy involves both persistent complement activation and platelet aggregation, which possibly promote ongoing thrombus formation. This case highlights that sacral/buttock retiform purpuric patches may be a presenting sign of infection with SARS-CoV-2 virus and may represent an ominous sign supporting a future severe disease course. In addition, biopsy specimen findings at separate time points demonstrate that cutaneous vasculopathy may persist despite adequate systemic anticoagulation, possibly due to the combination of persistent complement and platelet activation. Finally, occlusive thrombi in sacral/buttock retiform purpuric patches may contribute to future ulceration and significant cutaneous morbidity in patients who survive COVID-19.

Dermatological Manifestations Associated with COVID-19 Infection

The severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) causing the 2019 coronavirus disease (COVID-19) has infected millions in recent years and is a major public health concern. Various cutaneous manifestations of the COVID-19 disease have been identified. Skin is a mirror to internal disease and can be the presenting sign of COVID-19 disease. Several cutaneous manifestations can indicate severe COVID-19 disease. In the present scenario, physicians should know the various cutaneous manifestations of COVID-19 disease for early diagnosis and proper management of the disease.