Multisystem Inflammatory Syndrome in Children and Kawasaki Disease: Two Different Illnesses with Overlapping Clinical Features

Incidence of coronary artery lesions in children with recurrent Kawasaki disease

OBJECTIVE

Coronary artery lesions (CALs) are a major complication of Kawasaki disease (KD); however, data on CAL incidence and risk factors in recurrent KD are limited.

METHODS

Ninety-seven children with recurrent KD were retrospectively enrolled from 2013 to 2022, and CAL incidence was tracked during admission, discharge, and during follow-up.

RESULTS

Initially, 27.8% had CAL at admission and discharge, declining to 7.2% at 12 months post-discharge. Most patients (66 of 97, 68.0%) did not exhibit CAL at any of the time points, 7 cases presented CAL at all time points, indicating a persistent CAL. The remaining 20 cases presented CAL at admission but recovered at discharge or during follow-up. Notably, transient CALs had presented at discharge, or during the follow-up, but finally resolved at 12 months after discharge. Notably, prior IVIG resistance and increased prothrombin time seemed associated with CAL in recurrent KD, suggesting they could help identify patients needing close monitoring.

CONCLUSION

The study highlights decreasing CAL incidence over time in recurrent KD but with diverse patterns, emphasizing the importance of monitoring and further investigations to confirm these findings.

Navigating the Spectrum of Two Pediatric COVID-19 Complications: Multi-System Inflammatory Syndrome in Children and Post-Acute Sequelae of SARS-CoV-2 Infection

PURPOSE

This review summarizes the current scope of understanding associated with two common post-infectious complications associated with COVID-19 infection: Multi-System Inflammatory Syndrome in Children (MIS-C) and Post-Acute Sequelae of SARS-CoV-2 infection (PASC). It identifies current gaps in the knowledge and issues that may limit the ability to fill these gaps. This review provides a framework to drive continued research.

METHODS

A comprehensive review of the current literature was performed, identifying seminal articles describing the emergence of MIS-C and PASC, and works from the literature focused on the clinical implications and pathophysiologic understanding of these disorders.

FINDINGS

Although pediatric patients experienced few severe cases of acute COVID-19 infection, the burden of disease from post-infectious sequelae is substantial. Mortality is low, but morbidity is significant. There are still numerous unknowns about the pathophysiology of both MIS-C and PASC; however, with widespread immunity developing after increased vaccination and prior infection, it may be difficult to perform adequate prospective studies to answer pathophysiologic questions. Long-term sequalae of MIS-C seem to be minimal whereas, by definition, PASC is an ongoing problem and may be severe.

IMPLICATIONS

The rapid sharing of information regarding novel conditions such as MIS-C and PASC are key to interventions related to future post-infectious sequelae outside of those stemming from COVID-19. Although MIS-C seems unlikely to return as a clinical condition in substantial numbers, there is still significant learning that can be gleaned from existing patients about general aspects of epidemiology, equity, and pathophysiology. There is significant morbidity associated with PASC and additional resources need to be dedicated to determining appropriate and effective therapies moving forward.

Comparing the immune abnormalities in MIS-C to healthy children and those with inflammatory disease reveals distinct inflammatory cytokine production and a monofunctional T cell response

Multisystem inflammatory syndrome in children (MIS-C) is a severe, hyperinflammatory disease that occurs after exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The underlying immune pathology of MIS-C is incompletely understood, with limited data comparing MIS-C to clinically similar paediatric febrile diseases at presentation. SARS-CoV-2-specific T cell responses have not been compared in these groups to assess whether there is a T cell profile unique to MIS-C. In this study, we measured inflammatory cytokine concentration and SARS-CoV-2-specific humoral immunity and T cell responses in children with fever and suspected MIS-C at presentation (n = 83) where MIS-C was ultimately confirmed (n = 58) or another diagnosis was made (n = 25) and healthy children (n = 91). Children with confirmed MIS-C exhibited distinctly elevated serum IL-10, IL-6, and CRP at presentation. No differences were detected in SARS-CoV-2 spike IgG serum concentration, neutralisation capacity, antibody dependant cellular phagocytosis, antibody dependant cellular cytotoxicity or SARS-CoV-2-specific T cell frequency between the groups. Healthy SARS-CoV-2 seropositive children had a higher proportion of polyfunctional SARS-CoV-2-specific CD4+ T cells compared to children with MIS-C and those with other inflammatory or infectious diagnoses, who both presented a largely monofunctional SARS-CoV-2-specific CD4+ T cell profile. Treatment with steroids and/or intravenous immunoglobulins resulted in rapid reduction of inflammatory cytokines but did not affect the SARS-CoV-2-specific IgG or CD4+ T cell responses in MIS-C. In these data, MIS-C had a unique cytokine profile but not a unique SARS-CoV-2 specific humoral or T cell cytokine response.

A Case With Typical Clinical Manifestations of Kawasaki Disease and Multisystem Inflammatory Syndrome in Children Temporally Associated With SARS-CoV-2 Infection

Whether Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C) temporally associated with SARS-CoV-2 infection are two distinct syndromes or part of the same spectrum is not fully understood. In this report, we present the case of a five-year-old boy who fully satisfied the diagnostic criteria for both KD and MIS-C associated with SARS-CoV-2 infection. He tested positive for SARS-CoV-2 on an oropharyngeal swab antigen test approximately four weeks before the onset of symptoms. He had severe abdominal pain. Abdominal ultrasound showed ascites. He improved with initial (2 g/kg) and additional (1 g/kg) intravenous immunoglobulin (IVIG) therapy and intravenous methylprednisolone (initial dose, 2 mg/kg/day). Our case may lead to clarification of the pathogenesis of both diseases. Additionally, the recent history of SARS-CoV-2 infection for children with prolonged fever and no clear focus of infection should be checked, and, if present, clinicians should consider MIS-C temporally associated with SARS-CoV-2 infection. IVIG therapy is important for children with MIS-C who meet the diagnostic criteria for KD, even if diagnosed with MIS-C.

Clinical and Laboratory Characteristics of Kawasaki Disease and COVID-19-Related Multisystem Inflammatory Syndrome in Children

Geographical and racial factors constitute important distinctions between Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C), but no study has been conducted in Vietnam. Forty-one children with KD from January 2018 to July 2020 and 42 with KD/MIS-C from August 2020 to December 2022 were included in this study. Of the patients, 52.3% were aged between 12 and 35 months. Only two were aged over 5 years, and both were belong to the KD/MIS-C group. A 59.5% of the patients were male. Apart from fever, all symptoms tended to be more frequent in patients with KD/MIS-C. The prevalence of diffuse skin rash, hand and foot edema or erythema and gastrointestinal signs was significantly higher in patients hospitalized with KD/MIS-C. There was no significant difference in laboratory findings between the two groups. Coronary artery dilation was more frequently observed in patients with KD/MIS-C compared to those with KD (40.5% vs. 14.6%, P = 0.009).

Rising Kawasaki disease incidence in New Zealand: analysis of national population incidence and outcomes 2000-2017

OBJECTIVE

The recent epidemiology of Kawasaki disease (KD) in New Zealand (NZ) is unknown. Our aim was to describe the incidence, seasonal variation, long-term outcomes and mortality for KD in NZ.

DESIGN

Retrospective national database analysis.

SETTING

New Zealand.

PATIENTS

First hospitalisation and deaths diagnosed with KD.

MAIN OUTCOME MEASURES

Data were extracted for all hospital admissions in NZ coded as KD (International Classification of Diseases (ICD)-9 and ICD-10) from the National Minimum Dataset 1 January 2000 to 31 December 2017. Age, sex, ethnicity and associated diagnoses were available to review. Intervention rates for immunoglobulin administration were also analysed.

RESULTS

Over the study period, there were 1008 children with initial hospitalisation for KD. The mean age was 39.8 months (SD 37) and 592 (59%) were boys. The annual incidence rate of KD has increased from 12.2 to 19.5 per 100 000 children <5 years old (0.46 case increase per year; 95% CI 0.09 to 0.83). Children of Asian and Pacific Island ethnicities had the highest incidence (51.2 and 26.1/100 000, respectively). The highest growth in incidence was among East Asian children. The case mortality rate was low (12 of 1008, 1.2%); however, Māori were over-represented (6 of 12 deaths).

CONCLUSIONS

There is evidence of increasing KD hospitalisation in NZ, similar to recent studies from Northeast Asia and Australia. KD incidence data were available for retrospective review from a national database, but data on complications and outcomes were incomplete. Notification for KD and an active national surveillance system are recommended to improve care. Future work should focus on factors contributing to poorer outcomes in Māori.

The use of neutrophil-lymphocyte ratio for the prediction of refractory disease and coronary artery lesions in patients with Kawasaki disease

BACKGROUND

Kawasaki disease is a vasculitis that can lead to cardiac complications, including coronary artery disease and cardiogenic shock. Various scoring systems have been developed to determine those that will be refractory to routine intravenous immunoglobulin therapy or develop coronary artery disease. The objective of this study was to determine if the neutrophil-lymphocyte ratio could predict refractory disease and coronary artery lesions in patients with Kawasaki disease.

METHODS

A systematic review of the literature was performed to identify manuscripts describing comparisons of neutrophil-lymphocyte ratio between those who had refractory disease and those who did not, and between those who developed coronary artery lesions and those who did not. Mean difference was compared between groups. Areas under the curve were utilised to determine the pooled area under the curve.

RESULTS

12 studies with 5593 patients were included in the final analyses of neutrophil-lymphocyte ratio for the prediction of refractory disease. Neutrophil-lymphocyte ratio before therapy was higher in refractory disease with a mean difference of 2.55 (p < 0.01) and pooled area under the curve of 0.724. Neutrophil-lymphocyte ratio after therapy was higher in refractory disease with a mean difference of 1.42 (p < 0.01) and pooled area under the curve for of 0.803. Five studies with 1690 patients were included in the final analyses of neutrophil-lymphocyte ratio for the prediction of coronary artery lesions. Neutrophil-lymphocyte ratio before therapy was higher in coronary artery lesions with a mean difference of 0.65 (p < 0.01).

CONCLUSION

The use of neutrophil-lymphocyte ratio may help physicians in the identification of patients at risk of refractory disease and coronary artery lesions in patients with Kawasaki disease.

Prolonged Elevations of Factor VIII and von Willebrand Factor Antigen After Multisystem Inflammatory Syndrome in Children

Multisystem Inflammatory Syndrome in Children (MIS-C) is a late systemic inflammatory response to a recent mild or asymptomatic coronavirus disease of 2019 infection. The pathophysiology is incompletely understood but it often features significant coagulopathy along with cardiac and endothelial dysfunction. Endothelial inflammation has been primarily described in acute coronavirus disease of 2019 infection, with less characterization in MIS-C. Here we describe novel findings of nearly universal severe and prolonged factor VIII (FVIII) and von Willebrand factor antigen elevations in an institutional cohort of patients with MIS-C ages younger than or 21 years old (N=31). All patients had elevated acute phase reactants and D-dimer at presentation and met published criteria for MIS-C. FVIII was high at presentation in 97% of patients but continued to rise during the ensuing weeks of treatment to a mean 429%, peaking on median day 17 of illness as an outpatient. FVIII levels were >600% in multiple patients. von Willebrand factor antigen was measured less frequently but showed similar trends. These escalations occurred amidst resolving cardiac dysfunction and acute phase reactant normalization and despite patients receiving multimodal anti-inflammatory treatments and aspirin and enoxaparin thromboprophylaxis. No thrombotic events occurred. Endothelial dysfunction represented by very elevated FVIII levels may persist longer than other acute phase reactants may reflect.

A comparison of pediatric inflammatory multisystem syndrome temporarily-associated with SARS-CoV-2 and Kawasaki disease

The connection between Pediatric Inflammatory Multisystem Syndrome (PIMS) and Kawasaki Disease (KD) is not yet fully understood. Using the same national registry, clinical features and outcome of children hospitalized in Germany, and Innsbruck (Austria) were compared. Reported to the registry were 395 PIMS and 69 KD hospitalized patients. Patient age in PIMS cases was higher than in KD cases (median 7 [IQR 4-11] vs. 3 [IQR 1-4] years). A majority of both PIMS and KD patients were male and without comorbidities. PIMS patients more frequently presented with organ dysfunction, with the gastrointestinal (80%), cardiovascular (74%), and respiratory (52%) systems being most commonly affected. By contrast, KD patients more often displayed dermatological (99% vs. 68%) and mucosal changes (94% vs. 64%), plus cervical lymph node swelling (51% vs. 34%). Intensive care admission (48% vs. 19%), pulmonary support (32% vs. 10%), and use of inotropes/vasodilators (28% vs. 3%) were higher among PIMS cases. No patients died. Upon patient discharge, potentially irreversible sequelae-mainly cardiovascular-were reported (7% PIMS vs. 12% KD). Despite differences in age distribution and disease severity, PIMS and KD cases shared many common clinical and prognostic characteristics. This supports the hypothesis that the two entities represent a syndrome continuum.

SARS-CoV-2 infection in the context of Kawasaki disease and multisystem inflammatory syndrome in children

Recent studies have noted an increasing number of Kawasaki-like cases in the pediatric population following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In the literature, the condition is described as multiple inflammatory syndrome in children (MIS-C) or pediatric inflammatory syndrome (PIMS). A similar clinical course of Kawasaki disease (KD) and MIS-C causes difficulties in distinguishing between both conditions. However, the differential diagnosis is crucial since patients with MIS-C can present severe symptoms (myocardial dysfunction, fever, mucocutaneous symptoms) and require more extensive monitoring during treatment than children diagnosed with KD. Along with assessing epidemiological and genetic factors, it is imperative to estimate the risk of developing MIS-C in KD patients with confirmed SARS-CoV-2 infection. Genetic predispositions, such as the ITPKC gene polymorphism in KD, ACE deletion (D) polymorphism in SARS-CoV-2, and inborn errors of immunity (IEIs) in MIS-C affect the regulation of immune system complex clearances and cellular adaptations. The virus has a tropism for both vascular and respiratory cells, which further causes additional symptoms necessitating standard therapy with antithrombotic treatment. The diagnostic criteria for KD, MIS-C, and SARS-CoV-2 help differentiate each condition and optimize treatment strategies. Unfortunately, long-term outcomes in KD patients who develop MIS-C due to SARS-CoV-2 infection have been inadequately documented due to the timing of the pandemic, further displaying the need for longitudinal studies in these patients. This review underlines the differences in diagnosis and treatment of KD and MIS-C. Overall, children with KD may develop MIS-C in the setting of SARS-CoV-2 infection, but further research is needed to outline specific etiologies, prognostic factors, and diagnoses.

Incidence of Kawasaki Disease Before and After the COVID-19 Pandemic in Japan: Results of the 26th Nationwide Survey, 2019 to 2020

IMPORTANCE

Global studies have reported that the incidence of Kawasaki disease (KD) declined during the COVID-19 pandemic. These studies suggest that the global pandemic and its accompanying mitigation measures may provide an important opportunity to explore the hypothesis of a KD pathogenesis.

OBJECTIVE

To compare changes in KD incidence in Japan before and after the start of the COVID-19 pandemic.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study was conducted using the data set from Japan's 26th nationwide KD survey that obtained information on patients who were diagnosed with KD in Japan from January 1, 2019, through December 31, 2020.

MAIN OUTCOMES AND MEASURES

Kawasaki disease incidence rates were calculated by referring to the national population data in the vital statistics data for Japan.

RESULTS

A total of 28 520 patients were identified (16 236 male individuals [56.9%]; median [IQR] age, 26 [14-44] months). A total of 17 347 patients were diagnosed with KD in 2019 and 11 173 were diagnosed in 2020, representing a 35.6% reduction in the number of patients diagnosed in 2020 compared with the previous year. Patient distributions for days of illness at the first hospital visit were almost identical in 2019 and 2020, suggesting that the decrease in KD incidence likely was not associated with pandemic-related delays in seeking treatment. The proportion of patients diagnosed with KD who were younger than 12 months was significantly larger in 2020 than in 2019 (21.6% vs 19.4%; P < .001). Compared with KD incidence among younger patients, the incidence among those 24 months and older declined rapidly after initiation of COVID-19 special mitigation measures, with a greater percentage reduction (58.3% reduction in July), but rebounded faster after the end of the special mitigation period. By contrast, the incidence among patients younger than 12 months declined moderately after the initiation of the special mitigation period, with a lower percentage reduction (40.3% reduction in October), and rebounded at a later phase.

CONCLUSIONS AND RELEVANCE

In this cohort study, the number of patients diagnosed with KD decreased by approximately one-third across Japan in 2020, with no indication that parents avoided a hospital visit. Differences in KD incidence reduction patterns before and after the initiation of COVID-19 pandemic mitigation measures were found in patients with KD aged younger than 12 months compared with those 24 months or older, suggesting a potential KD pathogenesis involving transmission among children.

Complications of severe acute respiratory syndrome coronavirus 2 infection in children

PURPOSE OF REVIEW

Although during the initial stages of COVID-19 pandemic, the pediatric population seemed to be less affected, a number of SARS-CoV-2-related manifestations emerged over time, the principal of which is the multisystem inflammatory syndrome in children (MIS-C). Here we provide an update on the main pediatric disorders associated with SARS-CoV-2 infection.

RECENT FINDINGS

MIS-C is novel postinfectious manifestation with clinical features similar to Kawasaki disease and characterized by intense systemic inflammation affecting multiple organs. Many children required intensive care therapy because of circulatory shock, usually of myocardial origin. Appropriate treatment with immunomodulatory therapies led to favorable outcomes in most patients, with recovery of overall health and cardiac dysfunction. In addition to MIS-C, a variety of other complications of COVID-19 in children have been described, including thrombotic events, neurologic manifestations, and chilblain-like lesions. There is still uncertainty about the true prevalence of long COVID in children and its distinction from pandemic-related complaints.

SUMMARY

The experience gained so far with MIS-C and the other SARS-CoV-2-related complications in children and adolescents will facilitate accurate diagnosis and appropriate treatment. Further studies are needed to elucidate the pathophysiology of MIS-C and to determine the real impact of long-COVID in the pediatric age group.

Multisystem inflammatory syndrome in adults: A systematic review and meta-analysis of the rheumatological spectrum of complications post COVID-19 infection

Multisystem inflammatory syndrome in adults (MIS-A) is a rare but severe complication in adults infected with SARS-CoV-2. However, the pathophysiology remains elusive, as the limited number of reports preclude a broader understanding of this syndrome. We conducted this systematic review to explore the clinical spectrum of MIS-A, in particular its rheumatological manifestations. Meta-analyses of case-series were also performed. We identified 28 patients from 14 case reports and two case series of MIS-A. This disease occurred equally in both genders, with a mean age of 33 + 10 years old, and predominantly in those of African descent (40%). Rheumatological manifestations consisted of Kawasaki Disease (KD)-like symptoms. Ninety percent of patients had positive COVID-19 serology tests, while 48% of patients were negative for COVID-19 RT-PCR test. Twelve patients were admitted to ICU and unfortunately two died. Although the signs and symptoms of MIS mimicked KD, the gastro-intestinal findings were more prominent in the former group. The demographic make-up was also different, with MIS-A occurring mostly in those of African descent. Importantly, unlike their paediatric counterparts, the adult group did not have coronary artery abnormalities. Long-term monitoring is needed as safety data is scarce. Of note, although the prognosis of MIS-A is excellent, the life-threatening nature of this syndrome demands intensive care unit level of care and mechanical support. During the COVID-19 pandemic, a constellation of KD symptoms in an adult patient should alert the clinician to the possibility of MIS-A.

Risk Factors and Predictive Models for Intravenous Immunoglobulin Resistance in Children with Recurrent Kawasaki Disease

Purpose

To explore the risk factors and develop predictive models for intravenous immunoglobulin (IVIG) resistance in children with recurrent Kawasaki disease (KD).

Patients and Methods

Patients with recurrent KD were retrospectively reviewed. Clinical and laboratory data at recurrence were collected and compared between patients with and without IVIG resistance. The patients were randomly divided into training and validation cohorts for model development and validation. All variables were subjected to standard Lasso and its variant group Lasso analyses, respectively, to construct predictive models. Model performance was evaluated by receiver operating characteristics (ROC) curves, calibration curves, and Hosmer-Lemeshow tests.

Results

A total of 90 children with recurrent KD were included. A total of 16 cases were IVIG resistant. The patients with IVIG resistance had higher age and IVIG resistance probability at the first episode, increased CRP levels, neutrophil count, neutrophil percentage, direct bilirubin level, prothrombin time, and international normalized ratio, and decreased lymphocyte count, lymphocyte percentage, and serum sodium levels. Five variables including age and IVIG resistance at the first episode, lymphocytes count, serum sodium levels, and CRP levels were finally selected by standard Lasso (lLasso model) and four variables including age and IVIG resistance at the first episode, neutrophil percentage, and CRP levels were selected by group Lasso (gLasso). ROC curves suggested lLasso and gLasso models had similar excellent discrimination in both the training cohort (0.895 vs 0.906) and the validation cohort (0.855 vs 0.909). Hosmer-Lemeshow tests suggested the two models exerted a good calibration. Two nomograms were also constructed to facilitate the potential application of the two models.

Conclusion

Age and IVIG resistance at the first episode and some laboratory variables may be risk factors for IVIG resistance in recurrent KD. Two predictive models for IVIG resistance with excellent performance were established in recurrent KD. External validation should be performed before clinical use.

Pediatric emergency care in New York City during the COVID-19 pandemic shutdown and reopening periods

Objective

New York City (NYC) is home to the largest public healthcare system in the United States and was an early epicenter of coronavirus disease 2019 (COVID-19) infections. This system serves as the safety net for underserved and marginalized communities disproportionately affected by the pandemic. Prior studies reported substantial declines in pediatric emergency department (ED) volume during the initial pandemic surge, but few describe the ongoing impact of COVID-19 throughout the year. We evaluated the characteristics of pediatric ED visits to NYC public hospitals during the pandemic lockdown and reopening periods of 2020 compared to the prior year.

Methods

Retrospective cross-sectional analysis of pediatric ED visits from 11 NYC public hospitals from January 2019–December 2020. Visit demographics, throughput times, and diagnosis information during the early (3/7/20–6/7/20) and late (6/8/20–12/31/20) pandemic periods coinciding with the New York State of emergency declaration (3/7/20) and the first reopening date (6/7/20) were compared to similar time periods in 2019. Findings were correlated with key pandemic shutdown and reopening events.

Results

There was a 47% decrease in ED volume in 2020 compared to 2019 (125,649 versus 238,024 visits). After reopening orders began in June 2020, volumes increased but peaked at <60% of 2019 volumes. Admission rates, triage acuity, and risk of presenting with a serious medical illness were significantly higher in 2020 versus 2019 (P < 0.001). Time-to-provider times decreased however provider-to-disposition times increased during the pandemic (P < 0.001). Infectious and asthma diagnoses declined >70% during the pandemic in contrast to the year prior. After reopening periods began, penetrating traumatic injuries significantly increased compared to 2019 [+34%, Relative Risk: 3.2 (2.6, 3.8)].

Conclusions

NYC public hospitals experienced a sharp decrease in pediatric volume but an increase in patient acuity during both the initial pandemic surge and through the reopening periods. As COVID-19 variants emerge, the threat of the current pandemic expanding remains. Understanding its influence on pediatric ED utilization can optimize resource allocation and ensure equitable care for future surge events.

Childhood multisystem inflammatory syndrome associated with COVID-19 (MIS-C): Distinct from Kawasaki disease or part of the same spectrum?

One of the most challenging and intriguing phenomena observed during the COVID-19 pandemic has been the multisystem inflammatory syndrome in children (MIS-C). Patients with this condition present with some clinical features similar to those of Kawasaki disease (KD) and display signs and symptoms that are uncommon or rarely occur in this disorder, such as gastrointestinal complaints and myocarditis, often leading to myocardial failure and shock. In addition, patients' age is older than that of children with classic KD. Management is based on administering intravenous immunoglobulin, glucocorticoids, and anakinra in the most severe instances. It is still debated whether MIS-C and KD are different illnesses or represent a disease continuum.

Kawasaki Disease and Pediatric Infectious Diseases During the Coronavirus Disease 2019 Pandemic

OBJECTIVE

To assess the epidemiologic association between Kawasaki disease and common pediatric infectious diseases (PIDs) identified during the coronavirus disease 2019 (COVID-19) pandemic period to confirm whether the infection-triggered theory is a plausible hypothesis for the pathogenesis of Kawasaki disease.

STUDY DESIGN

A retrospective epidemiologic study was conducted using datasets obtained from Web-based surveillance of Kawasaki disease and PIDs in Japan. We compared weekly numbers of patients who developed Kawasaki disease and specific PIDs between 2020 and 2017-2019 and evaluated the association between the percent reduction in the number of patients with these diseases.

RESULTS

A total of 868 patients developed Kawasaki disease in 2020. During the social distancing period in 2020, the number of patients with Kawasaki disease was approximately 35% lower than in 2017-2019. Time from the onset of Kawasaki disease until the first hospital visit did not differ significantly among the examined years. The proportion of older children with Kawasaki disease decreased more than that of infants with Kawasaki disease (age <1 year), resulting in a significant difference in the proportion of infant patients between 2020 and 2017-2019 (24% vs 19%; P < .01). The number of patients with incomplete Kawasaki disease was unchanged from that of previous years. The weekly percent reduction in patient numbers differed between Kawasaki disease and PIDs during 2020, with no strong correlation between the 2 diseases.

CONCLUSIONS

Our data indicate that parents of patients with Kawasaki disease did not avoid hospital visits during the COVID-19 pandemic period. The findings indicate the possibility that triggering Kawasaki disease might be associated with presently unidentified respiratory pathogen(s) that potentially might be acquired from both within and outside the household.

Learning about Kawasaki disease from COVID-19 and the Multisystem Inflammatory Syndrome in Children

PURPOSE OF REVIEW

Multisystem Inflammatory Syndrome in Children (MIS-C) is a novel syndrome that has appeared in the wake of the severe acute respiratory syndrome coronavirus -2 pandemic, with features that overlap with Kawasaki disease (KD). As a result, new interest and focus have arisen in KD, and specifically mechanisms of the disease.

RECENT FINDINGS

A major question in the literature on the nature of MIS-C is if, and how, it may be related to KD. This has been explored using component analysis type studies, as well as other unsupervised analysis, as well as direct comparisons. At present, the answer to this question remains opaque, and several studies have interpreted their findings in opposing ways. Studies seem to suggest some relationship, but that MIS-C and KD are not the same syndrome.

SUMMARY

Study of MIS-C strengthens the likelihood that KD is a postinfectious immune response, and that perhaps multiple infectious agents or viruses underlie the disease. MIS-C and KD, while not the same disease, could plausibly be sibling disorders that fall under a larger syndrome of postacute autoimmune febrile responses to infection, along with Kawasaki shock syndrome.

Multisystem inflammatory syndrome in children (MIS-C) occurring in temporal proximity between siblings

We report a pair of siblings who developed multisystem inflammatory syndrome in children (MIS-C) in close temporal proximity after recent exposure to SARS-CoV-2. Both siblings presented with Kawasaki disease-like features and haemodynamic instability, with the onset of symptoms within 6 days of each other. Remarkably, one of the siblings was the elder of a pair of monozygotic twins. The younger monozygotic twin, however, did not develop MIS-C.

Multisystem Inflammatory Syndrome in Children

Background

Multisystem inflammatory syndrome in children (MIS-C) is a newly recognized condition affecting children with recent infection or exposure to coronavirus disease 2019 (COVID-19). MIS-C has symptoms that affect multiple organs systems, with some clinical features resembling Kawasaki disease (KD) and toxic shock syndrome (TSS).

Objective of the Review

Our goal was to review the current literature and describe the evaluation and treatment algorithms for children suspected of having MIS-C who present to the emergency department.

Discussion

MIS-C has a wide clinical spectrum and diagnosis is based on a combination of both clinical and laboratory findings. The exact mechanism of immune dysregulation of MIS-C is not well understood. Physical findings may evolve and do not necessarily appear at the same time. Gastrointestinal, cardiac, inflammatory, and coagulopathy manifestations and dysfunction are seen frequently in MIS-C.

Conclusions

The diagnosis of MIS-C is based on clinical presentation and specific laboratory findings. In the emergency setting, a high level of suspicion for MIS-C is required in patients exposed to COVID-19. Early diagnosis and prompt initiation of therapy offer the best chance for optimal outcomes.

Urticarial vasculitis: A potential signpost for multisystem inflammatory syndrome in children

Multisystem inflammatory syndrome in children (MIS-C) is a rare and serious complication of Sars-Cov-2 infection. Dermatologic manifestations are present in the majority of patients. Skin lesions found in children with MIS-C are classified into four categories: morbilliform, reticulated, scarlatiniform, and urticarial lesions. Clinicopathologic characterization within these categories is limited. Thus, we present a clear example of an urticarial lesion in the context of MIS-C with well-documented clinicopathologic phenomena. A previously healthy 16-year-old female presented with 3 weeks of an itchy, burning rash initially presenting on her right forearm (and lasting greater than 24 hours without migration) before spreading diffusely. She also reported fever, cough, myalgias, nausea, and vomiting of 4 weeks' duration. Physical examination revealed an edematous, maculopapular, nonblanching, erythematous rash covering the patient's upper extremities, abdomen, back, anterior thighs, and face. The patient tested positive for COVID-19. A low-grade leukocytoclastic vasculitis was noted along with intraluminal fibrin and rare microthrombi in vessels of the mid to deep dermis. The patient was diagnosed with MIS-C and urticarial vasculitis. She was treated with steroids and naproxen for subsequent MIS-C flares. Dapsone treatment was started for the urticarial vasculitis.

Surveillance in hospitalized children with infectious diseases in Japan: Pre- and post-coronavirus disease 2019

Introduction

The epidemic of coronavirus disease 2019 (COVID-19) rapidly spread worldwide, and the various infection control measures have a significant influence on the spread of many infectious diseases. However, there have been no multicenter studies on how the number of hospitalized children with various infectious diseases changed before and after the outbreak of COVID-19 in Japan.

Methods

We conducted a multicenter, prospective survey for hospitalized pediatric patients in 18 hospitals in Hokkaido Prefecture, Japan, from July 2019 to February 2021. We defined July 2019 to February 2020 as pre-COVID-19, and July 2020 to February 2021 as post-COVID-19. We surveyed various infectious diseases by sex and age.

Results

In total, 5300 patients were hospitalized during the study period. The number of patients decreased from 4266 in the pre-COVID-19 period to 701 (16.4%) post-COVID-19. Patients with influenza and RSV decreased from 308 to 795 pre-COVID-19 to zero and three (0.4%) post-COVID-19. However, patients with adenovirus (respiratory infection) only decreased to 60.9% (46–28) of pre-COVID levels. Patients with rotavirus, norovirus, and adenovirus gastroenteritis decreased markedly post-COVID-19 to 2.6% (38–1), 27.8% (97–27) and 13.5% (37–5). The number of patients with UTIs was similar across the two periods (109 and 90). KD patients decreased to 31.7% (161–51) post-COVID-19.

Conclusions

We suggest that current infection control measures for COVID-19 such as wearing masks, washing hands, and disinfecting hands with alcohol are effective against various infectious diseases. However, these effects vary by disease.

A Systematic Review of Characteristics Associated with COVID-19 in Children with Typical Presentation and with Multisystem Inflammatory Syndrome

Setting off a global pandemic, coronavirus disease 2019 (COVID-19) has been marked by a heterogeneous clinical presentation that runs the gamut from asymptomatic to severe and fatal. Although less lethal in children than adults, COVID-19 has nonetheless afflicted the pediatric population. This systematic review used clinical information from published literature to assess the spectrum of COVID-19 presentation in children, with special emphasis on characteristics associated with multisystem inflammatory syndrome (MIS-C). An electronic literature search for English and Chinese language articles in COVIDSeer, MEDLINE, and PubMed from 1 January 2020 through 1 March 2021 returned 579 records, of which 54 were included for full evaluation. Out of the total 4811 patients, 543 (11.29%) exhibited MIS-C. The most common symptoms across all children were fever and sore throat. Children presenting with MIS-C were less likely to exhibit sore throat and respiratory symptoms (i.e., cough, shortness of breath) compared to children without MIS-C. Inflammatory (e.g., rash, fever, and weakness) and gastrointestinal (e.g., nausea/vomiting and diarrhea) symptoms were present to a greater extent in children with both COVID-19 and MIS-C, suggesting that children testing positive for COVID-19 and exhibiting such symptoms should be evaluated for MIS-C.

Trends in Geographic and Temporal Distribution of US Children With Multisystem Inflammatory Syndrome During the COVID-19 Pandemic

IMPORTANCE

Multiple inflammatory syndrome in children (MIS-C) occurs in association with the COVID-19 pandemic.

OBJECTIVE

To describe the clinical characteristics and geographic and temporal distribution of the largest cohort of patients with MIS-C in the United States to date.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional analysis was conducted on clinical and laboratory data collected from patients with MIS-C. The analysis included patients with illness onset from March 2020 to January 2021 and met MIS-C case definition.

MAIN OUTCOMES AND MEASURES

Geographic and temporal distribution of MIS-C was compared with that of COVID-19 nationally, by region, and level of urbanicity by county. Clinical and laboratory findings and changes over time were described by age group and by presence or absence of preceding COVID-19.

RESULTS

A total of 1733 patients with MIS-C were identified; 994 (57.6%) were male and 1117 (71.3%) were Hispanic or non-Hispanic Black. Gastrointestinal symptoms, rash, and conjunctival hyperemia were reported by 53% (n = 931) to 67% (n = 1153) of patients. A total of 937 patients (54%) had hypotension or shock, and 1009 (58.2%) were admitted for intensive care. Cardiac dysfunction was reported in 484 patients (31.0%), pericardial effusion in 365 (23.4%), myocarditis in 300 (17.3%), and coronary artery dilatation or aneurysms in 258 (16.5%). Patients aged 0 to 4 years had the lowest proportion of severe manifestations, although 171 patients (38.4%) had hypotension or shock and 197 (44.3%) were admitted for intensive care. Patients aged 18 to 20 years had the highest proportions with myocarditis (17 [30.9%]), pneumonia (20 [36.4%]), acute respiratory distress syndrome (10 [18.2%]), and polymerase chain reaction positivity (39 [70.9%]). These older adolescents also had the highest proportion reporting preceding COVID-19-like illness (63%). Nationally, the first 2 MIS-C peaks followed the COVID-19 peaks by 2 to 5 weeks. The cumulative MIS-C incidence per 100 000 persons younger than 21 years was 2.1 and varied from 0.2 to 6.3 by state. Twenty-four patients (1.4%) died.

CONCLUSIONS AND RELEVANCE

In this cross-sectional study of a large cohort of patients with MIS-C, 2 peaks that followed COVID-19 peaks by 2 to 5 weeks were identified. The geographic and temporal association of MIS-C with the COVID-19 pandemic suggested that MIS-C resulted from delayed immunologic responses to SARS-CoV-2 infection. The clinical manifestations varied by age and by presence or absence of preceding COVID-19.

Current Understanding of Multisystem Inflammatory Syndrome (MIS-C) Following COVID-19 and Its Distinction from Kawasaki Disease

PURPOSE OF REVIEW

In this article, I have reviewed current reports that explore differences and similarities between multisystem inflammatory syndrome in children (MIS-C) and other known multisystem inflammatory diseases seen in children, particularly Kawasaki disease.

RECENT FINDINGS

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a human coronavirus causing the COVID-19 disease which emerged in China in December 2019 and spread rapidly to the entire country and quickly to other countries. Currently, there is a pandemic of SARS-CoV-2 infection that results in 20% of patients admitted to hospital with illness, with 3% developing intractable acute respiratory distress syndrome (ARDS) with high mortality. However, pediatric COVID-19 is still reported to be a mild disease, affecting only 8% of children. Pathogenesis in children is comparable to adults. There are suggested impaired activation of IFN-alpha and IFN regulator 3, decreased cell response causing impaired viral defense, yet the clinical course is mild, and almost all children recover from the infection without major complications. Interestingly, there is a subset of patients that develop a late but marked immunogenic response to COVID-19 and develop MIS-C. Clinical features of MIS-C resemble certain pediatric rheumatologic diseases, such as Kawasaki disease (mucocutaneous lymph node syndrome) which affects small-medium vessels. Other features of MIS-C resemble those of macrophage activation syndrome (MAS). However, recent research suggests distinct clinical and laboratory differences between MIS-C, Kawasaki disease, and MAS. Since the start of the SARS-CoV-2 pandemic, MIS-C has become the candidate for the most common cause of acquired heart disease in children.

Severe acute respiratory syndrome coronavirus 2 infection and critically ill children

PURPOSE OF REVIEW

Amidst an ongoing pandemic, the delineation of the pediatric consequence of infection from the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) virus is emerging. This review summarizes available pediatric data and covers the aspects of epidemiology, critical illness with acute infection [coronavirus disease 2019 (COVID-19)], the discovered multi-inflammatory syndrome in children (MIS-C), and management options.

RECENT FINDINGS

The available data from the source of the initial viral transmission and then through Europe, Africa, and the Western Hemisphere identifies important aspects of the SARS-CoV2 pandemic: 1) Pediatric infection occurs commonly, is likely underestimated, and transmission patterns remain incompletely described, 2) Pediatric patients suffer multiple end-organ injuries but COVID-19 is not the same prevalence in terms of severity as in adults, 3) MIS-C is a novel and life-threatening manifestation of exposure to the virus, 4) Management using a combination of supportive care, standard practice intensive care management, and anti-inflammatory agents is associated with recovery, 5) Long-term sequelae of viral exposure is unknown at this time.

SUMMARY

Emerging evidence suggests pediatric patients are at risk for severe and life-threatening effects of exposure to SARS-CoV2. As the pandemic continues, further research is warranted - particularly as a vaccine is not yet available for use in children.

[COVID-19 in children: SARS-CoV-2-related inflammatory multisystem syndrome mimicking Kawasaki disease]

SARS-CoV-2 pandemics is characterized by a high level of infectivity and a high mortality among adults at risk (older than 65 years, obesity, diabetes, systemic hypertension). Following a common viral pneumonia, a multisystem inflammatory syndrome sometimes occurs, including an Acute Respiratory Distress Syndrome (ARDS) carrying a high mortality. Unlike most common respiratory viruses, children seem less susceptible to SARS-CoV-2 infection and generally develop a mild disease with low mortality. However, clusters of severe shock associated with high levels of cardiac biomarkers and unusual vasoplegia requiring inotropes, vasopressors and volume loading have been recently described. Both clinical symptoms (i.e., high and persistent fever, gastrointestinal disorders, skin rash, conjunctivitis and dry cracked lips) and biological signs (e.g., elevated CRP/PCT, hyperferritinemia) resembled Kawasaki disease. In most instances, intravenous immunoglobin therapy improved the cardiac function and led to full recovery within a few days. However, adjunctive steroid therapy and sometimes biotherapy (e.g., anti-IL-1Ra, anti-IL-6 monoclonal antibodies) were often necessary. Although almost all children fully recovered within a week, some of them developed coronary artery dilation or aneurysm. Thus, a new 'Multisystem Inflammatory Syndrome associated with SARS-CoV-2' has been recently described in children and helps to better understand Kawasaki disease pathophysiology.

Is leukopenia and lymphopenia a characteristic feature of COVID-19 in children?

OBJECTIVES

To analyze whether leucopenia and lymphopenia a characteristic feature of children with COVID-19 and to find out its association with the disease severity.

METHODS

This was a descriptive cross-sectional study conducted at The Children's Hospital Lahore from March 2020 to October 2020. All confirmed cases of COVID-19 infection and post-COVID MIS-C/Kawasaki Disease diagnosed on the basis of RT-PCR and Antibody test respectively were included. Complete blood and differential counts were performed on the day of admission.

RESULTS

Out of a total of 83 patients 60 (72%) were diagnosed as COVID-19 and 23 (28%) as post-COVID MIS-C/KD. The mean age of children was 7.0±4.3 years (95%CI: 6.07 - 8.75) with a male preponderance 51 (61%). Twenty (24%) children had an underlying comorbidity and 7 (8%) were surgical cases. Our case fatality rate was 5 (6%) and all children who died had an underlying comorbid condition. In both, COVID and MIS-C/KD the mean leukocyte count was (14.0 ± 12.5 vs 13.6 ± 6.9 x109/L), respectively (p=0.888). The mean lymphocyte count in children with COVID was (39.1 ± 21.4%). Patients with MIS-C/KD showed significantly higher levels of neutrophil count (76.5 ± 15.0%) as compared to children with COVID (52.0 ± 22.1%), absolute lymphocyte count was (5.02±4.81 vs 2.13±0.95 x109/L) in COVID and MIS-C respectively (p=<0.001). In 60 COVID-19 patients, the mean neutrophil lymphocyte ratio (NLR) in mild-moderate and severe-critical group was 2.00 and 5.08 respectively (p=0.009).

CONCLUSION

The blood picture of COVID-19 in children does not show leukopenia. NLR was a prognostic factor to assess the severity in COVID-19 patients. The presence of an underlying comorbid conditions is significant a risk factor for poor outcome.

Kawasaki disease recurrence in the COVID-19 era: a systematic review of the literature

Kawasaki disease (KD) is a vasculitis of unknown origin of small and medium caliber blood vessels, especially involving coronary arteries and is the leading cause of acquired heart disease in childhood in developed countries. Although rarely, it can recur: most recurrences occur within 2 years of the initial episode. No data are available on incidence of recurrent KD in Europe and multiple recurrences are rarely seen. We reviewed the medical literature on Kawasaki disease recurrence and reported a new case of Kawasaki disease recurrence in a child with SARS-CoV-2 infection. We believe that in our case SARS Cov2 acted as a trigger capable to determine, in a genetically susceptible individual, a second recurrence of the disease. In the Covid-19 era we affirm the importance for Kawasaki disease to be tested for SARS Cov2 infection.

SARS-CoV-2 infection triggering recurrence of Kawasaki disease in a 10-year-old child

SARS-CoV-2 infection has recently been related to a spectrum of hyper-inflammatory states in children. There is a striking similarity between these hyper-inflammatory states and Kawasaki disease (KD). We present an interesting case of KD recurrence in a 10-year-old child, who had previously developed KD at 4 years of age. His symptoms included fever, maculopapular rash and altered sensorium. Investigations showed noticeably elevated inflammatory markers, and an echocardiography revealed dilated coronary arteries. SARS-CoV-2 IgG antibodies were positive. The child responded dramatically to intravenous immunoglobulin and intravenous methylprednisolone. It is possible that SARS-CoV-2 infection triggered the recurrence of KD in this child who might have been genetically predisposed to KD.

Multisystem inflammatory syndrome in children and adults (MIS-C/A): Case definition & guidelines for data collection, analysis, and presentation of immunization safety data

This is a Brighton Collaboration Case Definition of the term “Multisystem Inflammatory Syndrome in Children and Adults (MIS-C/A)” to be utilized in the evaluation of adverse events following immunization. The case definition was developed by topic experts convened by the Coalition for Epidemic Preparedness Innovations (CEPI) in the context of active development of vaccines for SARS-CoV-2. The format of the Brighton Collaboration was followed, including an exhaustive review of the literature, to develop a consensus definition and defined levels of certainty. The document underwent peer review by the Brighton Collaboration Network and by selected expert external reviewers prior to submission. The comments of the reviewers were taken into consideration and edits incorporated into this final manuscript.

Discriminating Multisystem Inflammatory Syndrome in Children Requiring Treatment from Common Febrile Conditions in Outpatient Settings

OBJECTIVES

To examine whether patients with multisystem inflammatory syndrome in children (MIS-C) demonstrated well-defined clinical features distinct from other febrile outpatients, given the difficulties of seeing acute care visits during the severe acute respiratory syndrome coronavirus 2 pandemic and the risks associated with both over- and underdiagnosis of MIS-C.

STUDY DESIGN

This case-controlled study compared patients diagnosed with and treated for MIS-C at a large urban children's hospital with patients evaluated for fever at outpatient acute care visits during the peak period of MIS-C. Symptomatology and available objective data were extracted. Comparisons were performed using t tests with corrections for multiple comparisons, and multivariable logistic regression to obtain ORs.

RESULTS

We identified 44 patients with MIS-C between April 16 and June 10, 2020. During the same period, 181 pediatric patients were evaluated for febrile illnesses in participating outpatient clinics. Patients with MIS-C reported greater median maximum reported temperature height (40°C vs 38.9, P < .0001), and increased frequency of abdominal pain (OR 12.5, 95% CI [1.65-33.24]), neck pain (536.5, [2.23-129,029]), conjunctivitis (31.3, [4.6-212.8]), oral mucosal irritation (11.8, [1.4-99.4]), extremity swelling or rash (99.9, [5-1960]), and generalized rash (7.42, [1.6-33.2]). Patients with MIS-C demonstrated lower absolute lymphocyte (P < .0001) and platelet counts (P < .05) and greater C-reactive protein concentrations (P < .001).

CONCLUSIONS

Patients treated for MIS-C due to concern for potential cardiac injury show combinations of features distinct from other febrile patients seen in outpatient clinics during the same period.

Murine Typhus in 5 Children Hospitalized for Multisystem Inflammatory Syndrome in Children

Multisystem inflammatory syndrome in children (MIS-C) is an emerging disease described in children in association with infection or epidemiological link to severe acute respiratory syndrome coronavirus 2. Signs and symptoms include fever, rash, and cardiac dysfunction; US Centers for Disease Control and Prevention have put forth broad criteria for diagnosis. The illness is serious and can progress rapidly to heart failure and death. However, findings in MIS-C are nonspecific, and there is significant overlap with other systemic illnesses, including Kawasaki disease and several viral and bacterial infections. We present 5 children admitted to a teaching hospital within an 11-day period in May 2020 for MIS-C evaluation who were later diagnosed with murine typhus. Typhus is a rickettsial infection that presents with fever and rash, and, although usually self-limited, responds well to treatment with doxycycline to shorten the course of illness. Clinical and laboratory characteristics of these children are presented to illustrate similarities to MIS-C, which can also be shared with viral, bacterial, or other regional endemic infections, as well as noninfectious inflammatory diseases. This case series serves to remind pediatric hospitalists to be vigilant to avoid premature closure on MIS-C for children admitted with fever and systemic inflammation. Maintaining a wide differential diagnosis in approaching such patients is of utmost importance as community exposure to severe acute respiratory syndrome coronavirus 2 is likely and evidence of past infection becomes commonplace.

Childhood Multisystem Inflammatory Syndrome: An Emerging Disease with Prominent Cardiovascular Involvement-A Scoping Review

Multisystem inflammatory syndrome in children (MIS-C) or paediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 (PIMS-TS) is an emerging disease in children affected with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection and thought to be an immune-mediated post-infectious complication of SARS-CoV-2. The disease presentation is similar to Kawasaki disease but has certain distinguishing features. The exact pathogenesis is still not clear but an aberrant immune response, antibody-mediated vascular damage and virus-mediated abnormal type I and III interferon-gamma response are thought to be responsible. Most children who are previously healthy present after 2–4 weeks of SARS-CoV-2 infections with febrile illness of short duration with prominent gastrointestinal, cardiac and hematologic manifestations, progressing to vasoplegic shock, requiring vasopressor therapy. Cardiovascular involvement is prominently marked by acute myocardial injury/myocarditis and the development of coronary artery aneurysms. Laboratory markers of inflammation are elevated uniformly. Most children require intensive care, and few need invasive ventilation. The treatment mainly consists of anti-inflammatory and immunomodulatory therapy like intravenous immunoglobulins and steroids. The overall prognosis is good and reported mortality rates are 0–4%.

COVID-19 in children: Pathogenesis and current status

Background: Since its initial description in December 2019 in Wuhan, China, coronavirus disease 2019 (COVID-19) has rapidly progressed into a worldwide pandemic, which has affected millions of lives. Unlike the disease in adults, the vast majority of children with COVID-19 have mild symptoms and are largely spared from severe respiratory disease. However, there are children who have significant respiratory disease, and some may develop a hyperinflammatory response similar to that seen in adults with COVID-19 and in children with Kawasaki disease (KD), which has been termed multisystem inflammatory syndrome in children (MIS-C). Objective: The purpose of this report was to examine the current evidence that supports the etiopathogenesis of COVID-19 in children and the relationship of COVID-19 with KD and MIS-C as a basis for a better understanding of the clinical course, diagnosis, and management of these clinically perplexing conditions. Results: The pathogenesis of COVID-19 is carried out in two distinct but overlapping phases of COVID-19: the first triggered by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) itself and the second by the host immune response. Children with KD have fewer of the previously described COVID-19-associated KD features with less prominent acute respiratory distress syndrome and shock than children with MIS-C. Conclusion: COVID-19 in adults usually includes severe respiratory symptoms and pathology, with a high mortality. It has become apparent that children are infected as easily as adults but are more often asymptomatic and have milder disease because of their immature immune systems. Although children are largely spared from severe respiratory disease, they can present with a SARS-CoV-2-associated MIS-C similar to KD.

An Algorithmic Approach to Management of COVID-19 Associated Multisystem Inflammatory Syndrome in Children

Collapse

Incidence of Kawasaki disease before and during the COVID-19 pandemic: a retrospective cohort study in Japan

BACKGROUND

Epidemiological studies in Kawasaki disease (KD) have suggested infectious aetiology. During the COVID-19 pandemic, measures for mitigating SARS-CoV-2 transmission also suppress the circulation of other contagious microorganisms. The primary objective is to compare the number and incidence of KD before and during the COVID-19 pandemic in Japan, and the secondary objective is to investigate temporal association between the KD epidemiology and activities of SARS-CoV-2 and other viral and bacterial infections.

METHODS

A retrospective cohort study was conducted between 2016 and 2020 in Kobe, Japan. We collected information of hospitalised KD children in Kobe. Child population was identified through the resident registry system. Activity of COVID-19 and 11 other infectious diseases was derived from a public health monitoring system. Monthly change of KD incidence was analysed using a difference-in-difference regression model.

RESULTS

Throughout the study period, 1027 KD children were identified. KD had begun to decline in April 2020, coinciding with the beginning of the COVID-19 pandemic. The number of KD cases (n=66) between April and December 2020 was 40% of the average in the same period in 2016-2019 (165/year). Annual KD incidence was 315, 300, 353, 347 and 188/100 000 children aged 0-4 years in 2016-2020, respectively. The difference-in-difference value of KD incidence was significantly reduced in the fourth quarter in 2020 (-15.8, 95% CI -28.0 to -3.5), compared with that in 2016-2019. Sentinel surveillance showed a marked decrease of all infectious diseases except exanthema subitum after the beginning of the COVID-19 pandemic. There were 86 COVID-19 cases aged <10 years and no KD children associated with COVID-19.

CONCLUSION

This study showed that the number and incidence of KD was dramatically reduced during the COVID-19 pandemic in Japan. This change was temporally associated with decreased activities of various infectious diseases other than COVID-19, supporting the hypothesis of infection-triggered pathogenesis in KD.

Multisystem Inflammatory Syndrome in Children: Unique Disease or Part of the Kawasaki Disease Spectrum?

One of the most intriguing and mysterious phenomena observed during the COVID-19 pandemic has been represented by the occurrence of the multisystem inflammatory syndrome in children and adolescents (MIS-C). Patients with this condition have some overlapping signs and symptoms with those of Kawasaki disease (KD), but also display clinical features that are uncommon or less frequent in this illness, such as diarrhea, abdominal pain and myocardial involvement. The sickest patients may develop multiorgan failure and shock, usually due to myocarditis. Management is based on the administration of intravenous immunoglobulin, glucocorticoids and, in the most severe instances, anakinra. It is still debated whether MIS-C and KD represent different illnesses or are part of the same disease spectrum. The aim of the present review is to analyze critically the evidence in favor of the latter hypothesis and to provide the authors' personal interpretation of the relationship between the two conditions.

Epidemiological and Clinical Profile of Pediatric Inflammatory Multisystem Syndrome - Temporally Associated with SARS-CoV-2 (PIMS-TS) in Indian Children

Background

We describe the demographic, clinical and labo-ratory findings along with the treatment and outcomes among children meeting the case definition of Pediatric Inflammatory Multisystem Syndrome - Temporally associated with SARS-CoV-2 (PIMS-TS).

METHODS

We analyzed the clinical and laboratory findings of children who presented with PIMS-TS during an 8-week period from May 4, 2020 to July 8, 2020.

RESULTS

We report 19 children with a median age of 6 year (IQR: 13 months-16 years), who met the case definition of PIMS-TS. All of them presented with fever. Multi organ involvement (79%), mucocutaneous involvement (74%), cardiovascular symptoms (63%) and gastrointestinal symptoms (42%) were the other features. Elevated levels of C-reactive protein was found in all of them and the majority of them had evidence of coagulopathy; intensive care admissions were needed in 12 (63%) and vasoactive medications were given to 6 (31.5%) children. There were no deaths.

CONCLUSION

Children with PIMS-TS present with a wide range of signs and symptoms. Fewer children in this series had coronary artery abnormalities, and there was a low incidence of RT-PCR positivity with high presence of SARS-CoV-2 antibodies.

Coronavirus Desease 2019 (COVID-19) in Children: Lessons from Pediatric Rheumatology

The clinical presentation and outcomes of infection with the novel coronavirus (COVID-19) are characterized by exceptional variability in manifestations, which depend on many factors, one of which is the patient’s age. One of the severe life-threatening manifestations in adults is severe acute respiratory syndrome (SARS-CoV-2), in some cases accompanied by the development of multiple organ failure. During the first two to three months of the COVID-19 pandemic, the global medical community was of the opinion that this disease in children is usually mild and not fatal. However, with the accumulation of new information, it became clear that there is a growing recognition of the existence of multisystem inflammatory syndrome in children, chronologically associated with SARS-CoV-2, which can lead to serious consequences. The article presents the main epidemiological, clinical and laboratory characteristics of the syndrome, as well as discusses the issues of its pathogenesis, differential diagnosis with a number of other acute conditions associated with an dysbalance of cytokines.

Cardiovascular impact of COVID-19 with a focus on children: A systematic review

BACKGROUND

Since the beginning of the pandemic, coronavirus disease-2019 (COVID-19) in children has shown milder cases and a better prognosis than adults. Although the respiratory tract is the primary target for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), cardiovascular involvement is emerging as one of the most significant and life-threatening complications of SARS-CoV-2 infection in adults.

AIM

To summarize the current knowledge about the potential cardiovascular involvement in pediatric COVID-19 in order to give a perspective on how to take care of them during the current pandemic emergency.

METHODS

Multiple searches in MEDLINE, PubMed were performed using the search terms "COVID-19" or "SARS-CoV-2" were used in combination with "myocardial injury" or "arrhythmia" or "cardiovascular involvement" or "heart disease" or "congenital heart disease" or "pulmonary hypertension" or "long QT" or "cardiomyopathies" or "channelopathies" or "Multisystem inflammatory system" or "PMIS" or "MIS-C" or "Pediatric multisystem inflammatory syndrome" or "myocarditis" or "thromboembolism to identify articles published in English language from January 1st, 2020 until July 31st, 2020. The websites of World Health Organization, Centers for Disease control and Prevention, and the Johns Hopkins Coronavirus Resource Center were reviewed to provide up to date numbers and infection control recommendations. Reference lists from the articles were reviewed to identify additional pertinent articles. Retrieved manuscripts concerning the subject were reviewed by the authors, and the data were extracted using a standardized collection tool. Data were subsequently analyzed with descriptive statistics. For Pediatric multisystemic inflammatory syndrome temporally associated with COVID-19 (PMIS), multiple meta-analyses were conducted to summarize the pooled mean proportion of different cardiovascular variables in this population in pseudo-cohorts of observed patients.

RESULTS

A total of 193 articles were included. Most publications used in this review were single case reports, small case series, and observational small-sized studies or literature reviews. The meta-analysis of 16 studies with size > 10 patients and with complete data about cardiovascular involvement in children with PMIS showed that PMIS affects mostly previously healthy school-aged children and adolescents presenting with Kawasaki disease-like features and multiple organ failure with a focus on the heart, accounting for most cases of pediatric COVID-19 mortality. They frequently presented cardiogenic shock (53%), ECG alterations (27%), myocardial dysfunction (52%), and coronary artery dilation (15%). Most cases required PICU admission (75%) and inotropic support (57%), with the rare need for extracorporeal membrane oxygenation (4%). Almost all of these children wholly recovered in a few days, although rare deaths have been reported (2%). Out of PMIS cases we identified 10 articles reporting sporadic cases of myocarditis, pulmonary hypertension and cardiac arrythmias in previously healthy children. We also found another 10 studies reporting patients with pre-existing heart diseases. Most cases consisted in children with severe COVID-19 infection with full recovery after intensive care support, but cases of death were also identified. The management of different cardiac conditions are provided based on current guidelines and expert panel recommendations.

CONCLUSION

There is still scarce data about the role of cardiovascular involvement in COVID-19 in children. Based on our review, children (previously healthy or with pre-existing heart disease) with acute COVID-19 requiring hospital admission should undergo a cardiac workup and close cardiovascular monitoring to identify and treat timely life-threatening cardiac complications.

Cytotoxic lymphocytes are dysregulated in multisystem inflammatory syndrome in children

Multisystem inflammatory syndrome in children (MIS-C) presents with fever, inflammation and multiple organ involvement in individuals under 21 years following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. To identify genes, pathways and cell types driving MIS-C, we sequenced the blood transcriptomes of MIS-C cases, pediatric cases of coronavirus disease 2019, and healthy controls. We define a MIS-C transcriptional signature partially shared with the transcriptional response to SARS-CoV-2 infection and with the signature of Kawasaki disease, a clinically similar condition. By projecting the MIS-C signature onto a co-expression network, we identified disease gene modules and found genes downregulated in MIS-C clustered in a module enriched for the transcriptional signatures of exhausted CD8 + T-cells and CD56 dim CD57 + NK cells. Bayesian network analyses revealed nine key regulators of this module, including TBX21 , a central coordinator of exhausted CD8 + T-cell differentiation. Together, these findings suggest dysregulated cytotoxic lymphocyte response to SARS-Cov-2 infection in MIS-C.

Epidemiological and Clinical Profile of Pediatric Inflammatory Multisystem Syndrome - Temporally Associated with SARS-CoV-2 (PIMS-TS) in Indian Children

Background

We describe the demographic, clinical and laboratory findings along with the treatment and outcomes among children meeting the case definition of Pediatric Inflammatory Multisystem Syndrome — Temporally associated with SARS-CoV-2 (PIMS-TS).

Methods

We analyzed the clinical and laboratory findings of children who presented with PIMS-TS during an 8-week period from May 4, 2020 to July 8, 2020.

Results

We report 19 children with a median age of 6 year (IQR: 13 months-16 years), who met the case definition of PIMS-TS. All of them presented with fever. Multi organ involvement (79%), mucocutaneous involvement (74%), cardiovascular symptoms (63%) and gastrointestinal symptoms (42%) were the other features. Elevated levels of C-reactive protein was found in all of them and the majority of them had evidence of coagulopathy; intensive care admissions were needed in 12 (63%) and vasoactive medications were given to 6 (31.5%) children. There were no deaths.

Conclusion

Children with PIMS-TS present with a wide range of signs and symptoms. Fewer children in this series had coronary artery abnormalities, and there was a low incidence of RT-PCR positivity with high presence of SARS-CoV-2 antibodies.