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

Multisystem inflammatory syndrome in children: A review

AIM

To comprehensively review the literature on multisystem inflammatory syndrome in children (MIS-C).

METHODS

Narrative review of relevant studies published between April 2020 and January 2024.

RESULTS

MIS-C is a SARS-CoV-2-related hyperinflammatory syndrome developing 2-6 weeks after COVID-19 in genetically susceptible individuals. Persisting fever, mucocutaneous manifestations, GI and cardiac involvement, together with lymphopenia and elevated inflammatory and cardiac markers are the main clinical features. It is believed to recognise some pathogenetic and clinical overlap with Kawasaki disease. New case definitions have been proposed after an assessment of the diagnostic performance of existing criteria; epidemiological criterion is however progressively losing its usefulness as the pandemic turns into an endemic and in the areas with the highest rates of COVID-19 vaccination. Current guidelines recommend both intravenous immunoglobulin and glucocorticoids in the first-line immunomodulatory treatment, mainly based on comparative retrospective cohorts; the actual role of biologics remains to be adequately established. Strict follow-up is mandatory, especially for those with severe cardiac involvement, as longitudinal studies evaluate the long-term evolution of cardiac damage.

CONCLUSION

In this paper, we review the epidemiological, pathogenetic, clinical and prognostic features of MIS-C, and outline the main questions which still remain unanswered after more than 3 years of research.

Multisystem inflammatory syndrome in children associated with COVID-19: from pathophysiology to clinical management and outcomes

Multisystem inflammatory syndrome in children (MIS-C), also known as pediatric inflammatory multisystem syndrome (PIMS), is a new postinfectious illness associated with COVID-19, affecting children after SARS-CoV-2 exposure. The hallmarks of this disorder are hyperinflammation and multisystem involvement, with gastrointestinal, cardiac, mucocutaneous, and hematologic disturbances seen most commonly. Cardiovascular involvement includes cardiogenic shock, ventricular dysfunction, coronary artery abnormalities, and myocarditis. Now entering the fourth year of the pandemic, clinicians have gained some familiarity with the clinical presentation, initial diagnosis, cardiac evaluation, and treatment of MIS-C. This has led to an updated definition from the Centers for Disease Control and Prevention in the USA driven by increased experience and clinical expertise. Furthermore, the available evidence established expert consensus treatment recommendations supporting a combination of immunoglobulin and steroids. However, the pathophysiology of the disorder and answers to what causes this remain under investigation. Fortunately, long-term outcomes continue to look promising, although continued follow-up is still needed. Recently, COVID-19 mRNA vaccination is reported to be associated with reduced risk of MIS-C, while further studies are warranted to understand the impact of COVID-19 vaccines on MIS-C. We review the findings and current literature on MIS-C, including pathophysiology, clinical features, evaluation, management, and medium- to long-term follow-up outcomes.

Predicting Delayed Shock in Multisystem Inflammatory Disease in Children: A Multicenter Analysis From the New York City Tri-State Region

OBJECTIVES

Patients with multisystem inflammatory disease in children (MIS-C) are at risk of developing shock. Our objectives were to determine independent predictors associated with development of delayed shock (≥3 hours from emergency department [ED] arrival) in patients with MIS-C and to derive a model predicting those at low risk for delayed shock.

METHODS

We conducted a retrospective cross-sectional study of 22 pediatric EDs in the New York City tri-state area. We included patients meeting World Health Organization criteria for MIS-C and presented April 1 to June 30, 2020. Our main outcomes were to determine the association between clinical and laboratory factors to the development of delayed shock and to derive a laboratory-based prediction model based on identified independent predictors.

RESULTS

Of 248 children with MIS-C, 87 (35%) had shock and 58 (66%) had delayed shock. A C-reactive protein (CRP) level greater than 20 mg/dL (adjusted odds ratio [aOR], 5.3; 95% confidence interval [CI], 2.4-12.1), lymphocyte percent less than 11% (aOR, 3.8; 95% CI, 1.7-8.6), and platelet count less than 220,000/uL (aOR, 4.2; 95% CI, 1.8-9.8) were independently associated with delayed shock. A prediction model including a CRP level less than 6 mg/dL, lymphocyte percent more than 20%, and platelet count more than 260,000/uL, categorized patients with MIS-C at low risk of developing delayed shock (sensitivity 93% [95% CI, 66-100], specificity 38% [95% CI, 22-55]).

CONCLUSIONS

Serum CRP, lymphocyte percent, and platelet count differentiated children at higher and lower risk for developing delayed shock. Use of these data can stratify the risk of progression to shock in patients with MIS-C, providing situational awareness and helping guide their level of care.

How multisystem inflammatory syndrome in children discriminated from Kawasaki disease: a differentiating score based on an inception cohort study

BACKGROUND

About 25-50% of multisystem inflammatory syndrome in children (MIS-C) patients meet the criteria for diagnosis of Kawasaki disease (KD). The differentiation of both conditions is so challenging on clinical practice as the management of both is time dependant and precise diagnosis is fundamental.

METHOD

Data were collected from children < 18 years old hospitalized with MIS-C or KD. Patient demographics, clinical, and laboratory data were compared, and a discrimination score was created to assist in clinical differentiation.

RESULTS

72 patients with MIS-C and 18 with KD were included in the study. Patients with MIS-C had a higher prevalence of abdominal pain (p = 0.02), vomiting (p = 0.03), and cervical lymphadenopathy (p = 0.02) compared with KD cases. MIS-C patients had higher liver enzymes (aspartate aminotransferase (AST) (p = 0.04), alanine aminotransferase (ALT) (p = 0.03), serum creatinine (p = 0.03), and lower platelet count nadir (p = 0.02) than KD. Four variables were detected in the regression analysis model, and the independent predictors were utilized to generate a scoring model that distinguished MIS-C from KD with an area under the curve of 0.70.

CONCLUSION

This study constructed a prediction model for differentiation of MIS-C from KD based on clinical and laboratory profiles. This model will be valuable to guide clinicians in the treatment decisions. Key Points • Children with MIS-C are more likely to have gastrointestinal symptoms, cervical lymphadenopathy, and respiratory involvement than KD patients. • Elevated liver enzymes and lower platelet count are more pronounced laboratory findings in MIS-C than KD. • This study constructed a prediction model for differentiation of MIS-C from KD based on clinical and laboratory profiles. This model will be valuable to guide clinicians in the treatment decisions.

Misdiagnosis of multisystem inflammatory syndrome in children: A diagnostic challenge

AIMS

As the COVID-19 pandemic continues, multisystem inflammatory syndrome in children (MIS-C) maintains its importance in the differential diagnosis of common febrile diseases. MIS-C should be promptly diagnosed because corticosteroid and/or intravenous immunoglobulin treatment can prevent severe clinical outcomes. In this study, we aimed to evaluate clinical presentation, diagnostic parameters and management of MIS-C and compare its clinical features to those of common febrile disease.

METHODS

This study was conducted at a tertiary-level university hospital between December 2020 and October 2022. One hundred and six children who were initially considered to have MIS-C disease were included in the study. During the follow-up period in the hospital, when the clinical and laboratory findings were re-evaluated, 38 out of 106 children were diagnosed differently. The clinical and laboratory findings of 68 children followed up with the diagnosis of MIS-C and 38 children who were initially misdiagnosed as MIS-C but with different final diagnoses were retrospectively compared.

RESULTS

We identified 68 patients with MIS-C and 38 patients misdiagnosed as MIS-C during the study period. Infectious causes (71%), predominantly bacterial origin, were the most frequently confused conditions with MIS-C. Patients with MIS-C were older and had a more severe clinical course with high rates of respiratory distress, shock, and paediatric intensive care unit admission. While rash and conjunctivitis were more common among patients with MIS-C, cough, abdominal pain and diarrhoea were observed more frequently in patients misdiagnosed as MIS-C. Lower absolute lymphocyte counts, platelet counts and higher C-reactive protein and fibrinogen levels, pathological findings on echocardiography were the distinctive laboratory parameters for MIS-C. Multivariate analysis showed that older age, presence of conjunctivitis, high level of serum CRP and lower platelets were the most discriminative predictors for the diagnosis of MIS-C.

CONCLUSION

There are still no specific findings to diagnose MIS-C, which therefore can be confused with different clinical conditions. Further data are needed to assist the clinician in the differential diagnosis of MIS-C and the diagnostic criteria should be updated over time.

A Diagnostic Prediction Model to Distinguish Multisystem Inflammatory Syndrome in Children

OBJECTIVE

Features of multisystem inflammatory syndrome in children (MIS-C) overlap with other syndromes, making the diagnosis difficult for clinicians. We aimed to compare clinical differences between patients with and without clinical MIS-C diagnosis and develop a diagnostic prediction model to assist clinicians in identification of patients with MIS-C within the first 24 hours of hospital presentation.

METHODS

A cohort of 127 patients (<21 years) were admitted to an academic children's hospital and evaluated for MIS-C. The primary outcome measure was MIS-C diagnosis at Vanderbilt University Medical Center. Clinical, laboratory, and cardiac features were extracted from the medical record, compared among groups, and selected a priori to identify candidate predictors. Final predictors were identified through a logistic regression model with bootstrapped backward selection in which only variables selected in more than 80% of 500 bootstraps were included in the final model.

RESULTS

Of 127 children admitted to our hospital with concern for MIS-C, 45 were clinically diagnosed with MIS-C and 82 were diagnosed with alternative diagnoses. We found a model with four variables-the presence of hypotension and/or fluid resuscitation, abdominal pain, new rash, and the value of serum sodium-showed excellent discrimination (concordance index 0.91; 95% confidence interval: 0.85-0.96) and good calibration in identifying patients with MIS-C.

CONCLUSION

A diagnostic prediction model with early clinical and laboratory features shows excellent discrimination and may assist clinicians in distinguishing patients with MIS-C. This model will require external and prospective validation prior to widespread use.

Diagnostic Yield of Cardiac Biomarker Testing in Predicting Cardiac Disease and Multisystem Inflammatory Syndrome in Children in the Pandemic Era

OBJECTIVES

This study aimed to assess whether elevations in cardiac biomarkers are associated with pediatric cardiac diagnoses in the era of COVID-19 and multisystem inflammatory syndrome in children (MIS-C).

STUDY DESIGN

This single-center retrospective study analyzed children with a troponin drawn in the emergency department or inpatient unit between April 21 and December 31, 2020. The primary outcome was the presence of a cardiac diagnosis or MIS-C. Relationships among demographics, complaint, cardiac diagnostics, and cardiac biomarkers were analyzed.

RESULTS

Four hundred eighty-six patients (mean ± SD; age 13.1 ± 7.8 years; 46.7% women) met inclusion criteria, for whom a cardiac diagnosis (excluding MIS-C) was made in 27 (5.6%) patients, with MIS-C diagnosed in 14 (2.9%) patients. The sensitivity and specificity of an elevated initial high-sensitivity troponin T (hsTropT) value (>14 ng/L) in predicting the composite outcome of a cardiac diagnosis or MIS-C were 54% and 89%, respectively. Four percent of patients with negative initial troponin values were found to have a cardiac diagnosis or MIS-C. Multivariable regression analysis demonstrated that elevated hsTropT (>14 ng/L; odds ratio [OR] [95% confidence interval]: 4.9 [1.70-14.0]) and elevated N-terminal pro B-type natriuretic peptide values (>500 pg/mL; 6.4 [2.01-20.1]) were associated with increased odds of a cardiac diagnosis or MIS-C.

CONCLUSIONS

Children with elevated cardiac biomarkers have increased odds of a cardiac diagnosis or MIS-C and warrant workup regardless of indication for testing. Although a negative hsTropT may reassure providers, further investigation is critical in developing algorithms to reliably exclude cardiac disease.

Cytokine Profiling among Children with Multisystem Inflammatory Syndrome versus Simple COVID-19 Infection: A Study from Northwest Saudi Arabia

Simple Summary

Multisystem Inflammatory Syndrome in Children (MIS-C) is a novel syndrome associated with COVID-19. Its manifestations vary from asymptomatic to life-threatening disease. Cytokines are essential mediators of the inflammatory response during MIS-C. In this study, we analyzed the expression of inflammatory markers and cytokines in blood, reported the important clinical characteristics, and correlated these results with short- and mid-term outcomes. Significantly elevated levels of cytokines (IL-1β, IL-6, and GM-CSF) confirmed their role in the severity of manifestations, disease progression, and outcome. Thus, this is one of the earliest studies in Saudi Arabia to evaluate the inflammatory response (cytokine profile) of MIS-C, correlating the clinical phenomena.

Abstract

Background: Multisystem Inflammatory Syndrome in Children (MIS-C) is a novel syndrome associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection with varying clinical features. This study aimed to analyze the expression profiles of cytokines in blood, report the important clinical characteristics, and correlate these with the short- and mid-term outcomes. Methods: This cross-sectional study was conducted on hospitalized children with MIS-C from March 2021 to May 2022. Phenotypes were classified into two groups (A,B) according to the severity of the disease and the need for invasive respiratory support. Clinical features, laboratory parameters, and outcomes were reported. Results: We identified 60 children with MIS-C (mean age of 7.4 ± 3.8 years) compared to 30 age- and sex-matched controls with simple COVID-19. The clinical manifestations of MIS-C patients were fever (100%), respiratory (83.3%), GIT (80%), and conjunctivitis (80%). Twenty-seven MIS-C children (45%) required PICU admission due to shock and needed mechanical ventilation. Anemia, lymphopenia, and elevated levels of inflammatory and tissue injury markers were observed in the MIS-C groups (mainly B). High cytokine levels (IL-1β, IL-6, IFN-α, GM-CSF, and HMGB1) were observed acutely in the MIS-C children, and a persistent elevation of some cytokines were reported at midterm follow-up, especially in Group B. Conclusion: Robust inflammatory response to COVID-19 disease with elevated IL-1β, IL-6, and GM-CSF levels might explain the severity and outcome of the clinical syndrome.

Determination of Factors to Distinguish MIS-C from Acute Appendicitis in Children with Acute Abdominal Pain

INTRODUCTION

 The aim of this study was to make the differential diagnosis between acute appendicitis and multisystem inflammatory syndrome in children (MIS-C) for patients presenting with the complaint of acute abdominal pain (AAP) and to identify the determining factors for the diagnosis of MIS-C.

MATERIALS AND METHODS

 Eighty-one children presenting with AAP/suspected AAP were evaluated. Of these, 24 (29.6%) were included in the MIS-C group (MIS-C/g) and 57 were included in the suspected appendicitis group (S-A/g), which consisted of two subgroups: appendicitis group (A/g) and control observation group (CO/g).

RESULTS

 Comparing MIS-C/g, A/g, and CO/g, duration of abdominal pain (2.4, 1.5, 1.8 days), high-grade fever (38.8, 36.7, 37°C), severe vomiting, and severe diarrhea were higher in MIS-C/g. Lymphocytes count (LC) was lower, while values of C-reactive protein (CRP), ferritin, and coagulopathy were higher in MIS-C/g (p < 0.05). The optimal cutoffs for the duration of abdominal pain was 2.5 days; the duration of fever, 1.5 days; peak value of fever, 39°C; neutrophil count, 13,225 × 1,000 cell/µMoL; LC, 600 × 1,000 cell/µMoL; ferritin, 233 µg/L; and D-dimer, 16.4 mg/L (p < 0.05). The optimal cutoff for CRP was 130 mg/L (sensitivity 88.9, specificity 100%, positive predictive value 100%, NPV, negative predictive value 92.5%, p < 0.001). All patients in MIS-C/g tested positive by serology by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

CONCLUSION

 The duration of abdominal pain, presence of high-grade and prolonged fever, and evaluation of hemogram in terms of high neutrophil count and low LC exhibit high sensitivity and negative predictive value for MIS-C presenting with AAP. In case of doubt, inflammatory markers such as CRP, ferritin, D-dimer, and serology for SARS-CoV-2 should be studied to confirm the diagnosis.

Severe Acute Respiratory Syndrome Coronavirus 2 Infections in Children

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in children generally have milder presentations, but severe disease can occur in all ages. MIS-C and persistent post-acute COVID-19 symptoms can be experienced by children with previous infection and emphasize the need for infection prevention. Optimal treatment for COVID-19 is not known, and clinical trials should include children to guide therapy. Vaccines are the best tool at preventing infection and severe outcomes of COVID-19. Children suffered disproportionately during the pandemic not only from SARS-CoV-2 infection but because of disruptions to daily life, access to primary care, and worsening income inequalities.

Comparison of Multisystem Inflammatory Syndrome (MIS-C) and Dengue in Hospitalized Children

OBJECTIVE

Multisystem inflammatory syndrome (MIS-C) in children is a febrile illness that has overlapping presentation with other locally prevalent illnesses. Clinicolaboratory profile of children admitted with MIS-C and dengue were compared to understand their presentation at the outset.

METHODS

This was a retrospective study of children ≤ 12 y admitted with MIS-C (WHO definition) or laboratory-confirmed dengue between August 2020 and January 2021 at a tertiary center in North India.

RESULTS

A total of 84 children (MIS-C - 40; dengue - 44) were included. The mean (SD) age [83.5 (39) vs. 91.6 (35) mo] was comparable. Rash (72.5% vs. 22.7%), conjunctival injection (60% vs. 2.3%), oral mucocutaneous changes (27.5% vs. 0) and gallop rhythm (15% vs. 0) were seen more frequently with MIS-C, while petechiae [29.5% vs. 7.5%], myalgia (38.6% vs. 10%), headache (22.7% vs. 2.5%), and hepatomegaly (68.2% vs. 27.5%) were more common with dengue. Children with MIS-C had significantly higher C-reactive protein (124 vs. 3.2 mg/L) and interleukin 6 (95.3 vs. 20.7 ng/mL), while those with dengue had higher hemoglobin (12 vs. 10.2 g/dL) lower mean platelet count (26 vs. 140 × 10⁹/L), and greater elevation in aspartate (607 vs. 44 IU/L) and alanine (235.5 vs. 56 IU/L) aminotransferases. The hospital stay was longer with MIS-C; however, PICU stay and mortality were comparable.

CONCLUSION

In hospitalized children with acute febrile illness, the presence of mucocutaneous features and highly elevated CRP could distinguish MIS-C from dengue. The presence of petechiae, hepatomegaly, and hemoconcentration may favor a diagnosis of dengue.

Critically Ill Pediatric Patient and SARS-CoV-2 Infection

In December 2019 SARS-CoV-2 initiated a worldwide COVID-19 pandemic, which is still ongoing in 2022. Although adult elderly patients with chronic preexisting diseases had been identified as the most vulnerable group, COVID-19 has also had a significant impact on pediatric intensive care. Early in 2020, a new disease presentation, multisystemic inflammatory syndrome, was described in children. Despite the vaccination that is available for all age categories, due to its selection process, new viral mutations and highly variable vaccination rate, COVID-19 remains a significant clinical challenge in adult and pediatric intensive care in 2022.

Pharmacological treatment of COVID-19: an opinion paper

The precocity and efficacy of the vaccines developed so far against COVID-19 has been the most significant and saving advance against the pandemic. The development of vaccines has not prevented, during the whole period of the pandemic, the constant search for therapeutic medicines, both among existing drugs with different indications and in the development of new drugs. The Scientific Committee of the COVID-19 of the Illustrious College of Physicians of Madrid wanted to offer an early, simplified and critical approach to these new drugs, to new developments in immunotherapy and to what has been learned from the immune response modulators already known and which have proven effective against the virus, in order to help understand the current situation.

MIS-C frenzy: The importance of considering a broad differential diagnosis

We report a case of a 3 year-old boy with possible typhoid fever with recent travel to a typhoid endemic area who was primarily managed as a case of multisystem inflammatory syndrome in children (MIS-C). The patient was initially treated for tonsillitis after a 3 day history of persistent fever, sore throat, and constipation. The patient presented later when he deteriorated. Severe acute respiratory syndrome coronavirus (SARS-CoV-2) viral RNA was not detected but the antibodies were positive. The patient went on to develop mucosal, cardiac, and gastrointestinal manifestations and was subsequently treated with immunoglobulins and corticosteroids for MIS-C. Despite the rarity of MIS-C as a complication of COVID-19 infection, the endemic typhoid fever which is relatively more common was not ruled out. The patient additionally received antibiotics for a total of 5 weeks given his unremitting fever. Even during the COVID-19 pandemic, healthcare professionals should carry out timely testing to exclude more probable differential diagnoses, with area-specific common diseases given due diligence.

Imaging findings in acute pediatric coronavirus disease 2019 (COVID-19) pneumonia and multisystem inflammatory syndrome in children (MIS-C)

The two primary manifestations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in children are acute coronavirus disease 2019 (COVID-19) pneumonia and multisystem inflammatory syndrome (MIS-C). While most pediatric cases of acute COVID-19 disease are mild or asymptomatic, some children are at risk for developing severe pneumonia. In MIS-C, children present a few weeks after SARS-CoV-2 exposure with a febrile illness that can rapidly progress to shock and multiorgan dysfunction. In both diseases, the clinical and laboratory findings can be nonspecific and present a diagnostic challenge. Thoracic imaging is commonly obtained to assist with initial workup, assessment of disease progression, and guidance of therapy. This paper reviews the radiologic findings of acute COVID-19 pneumonia and MIS-C, highlights the key distinctions between the entities, and summarizes our understanding of the role of imaging in managing SARS-CoV-2-related illness in children.

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.

Laboratory parameters between multisystem inflammatory syndrome in children and Kawasaki disease

Multisystem inflammatory syndrome in children (MIS-C) associated with coronavirus disease 2019 (COVID-19) has been described to partially overlap with Kawasaki disease (KD) with regard to clinical symptoms, but they are unlikely to share the same disease entity. We conducted a systematic review and meta-analysis to characterize the laboratory parameters of MIS-C compared with those of KD and Kawasaki disease shock syndrome (KDSS). Databases were searched for studies on laboratory parameters of MIS-C (hematology, inflammatory markers, cardiac markers, and biochemistry) through May 31, 2021. Twelve studies with 3073 participants yielded 969 MIS-C patients. In terms of hematology, MIS-C patients had lower levels of leukocytes, absolute lymphocyte count and platelet count (PLT) than KD patients and had similar absolute neutrophil count (ANC) and hemoglobin (Hb) levels. In terms of inflammatory markers, MIS-C patients had higher levels of C-reactive protein, D-dimer and ferritin than KD patients and had similar levels of procalcitonin and erythrocyte sedimentation rate (ESR). In terms of cardiac markers, MIS-C patients had higher CPK levels than KD patients. The levels of N-terminal pro-brain natriuretic peptide, troponin and aspartate aminotransferase were not significantly different between MIS-C and KD patients. In terms of biochemistry, MIS-C patients had lower levels of albumin, sodium and alanine aminotransferase and higher levels of creatinine than KD patients. In addition, MIS-C patients had lower levels of PLT, Hb and ESR and higher levels of ANC than KDSS patients. Measurement of laboratory parameters might assist clinicians with accurate evaluation of MIS-C and further mechanistic research.

Multisystem inflammatory syndrome in children and Kawasaki disease: a critical comparison

Children and adolescents infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are predominantly asymptomatic or have mild symptoms compared with the more severe coronavirus disease 2019 (COVID-19) described in adults. However, SARS-CoV-2 is also associated with a widely reported but poorly understood paediatric systemic vasculitis. This multisystem inflammatory syndrome in children (MIS-C) has features that overlap with myocarditis, toxic-shock syndrome and Kawasaki disease. Current evidence indicates that MIS-C is the result of an exaggerated innate and adaptive immune response, characterized by a cytokine storm, and that it is triggered by prior SARS-CoV-2 exposure. Epidemiological, clinical and immunological differences classify MIS-C as being distinct from Kawasaki disease. Differences include the age range, and the geographical and ethnic distribution of patients. MIS-C is associated with prominent gastrointestinal and cardiovascular system involvement, admission to intensive care unit, neutrophilia, lymphopenia, high levels of IFNγ and low counts of naive CD4⁺ T cells, with a high proportion of activated memory T cells. Further investigation of MIS-C will continue to enhance our understanding of similar conditions associated with a cytokine storm.

Identifying pediatric patients with multisystem inflammatory syndrome in children presenting to a pediatric emergency department

OBJECTIVE

To compare clinical and laboratory features of children with Multisystem Inflammatory Syndrome in Children (MIS-C) to those evaluated for MIS-C in the Emergency Department (ED).

METHODS

We conducted a retrospective review of the medical record of encounters with testing for inflammatory markers in an urban, tertiary care Pediatric ED from March 1, 2020 to July 31, 2020. We abstracted demographic information, laboratory values, selected medications and diagnoses. We reviewed the record for clinical presentation for the subset of patients admitted to the hospital for suspected MIS-C. We then used receiver operating curves and logistic regression to evaluate the utility of candidate laboratory values to predict MIS-C status.

RESULTS

We identified 32 patients with confirmed MIS-C and 15 admitted and evaluated for MIS-C but without confirmation of SARS CoV-2 infection. We compared these patients to 267 encounters with screening laboratories for MIS-C. Confirmed MIS-C patients had an older median age, higher median fever on presentation and were predominantly of Hispanic and non-Hispanic Black race/ethnicity. All children with MIS-C had a C-reactive protein (CRP) >4.5 mg/dL, were more likely to have Brain Natriuretic Peptide >400 pg/mL (OR 10.50, 95%CI 4.40-25.04), D-Dimer >3 μg/mL (7.51, [3.18-17.73]), and absolute lymphocyte count (ALC) <1.5 K/mcL (21.42, [7.19-63.76]). We found CRP >4.5 mg/dL and ALC <1.5 K/mcL to be 86% sensitive and 91% specific to identify MIS-C among patients screened in our population.

CONCLUSIONS

We identified that elevated CRP and lymphopenia was 86% sensitive and 91% specific for identification of children with MIS-C.

Online Interactive Platform for COVID-19 Literature Visual Analytics: Platform Development Study

BACKGROUND

Papers on COVID-19 are being published at a high rate and concern many different topics. Innovative tools are needed to aid researchers to find patterns in this vast amount of literature to identify subsets of interest in an automated fashion.

OBJECTIVE

We present a new online software resource with a friendly user interface that allows users to query and interact with visual representations of relationships between publications.

METHODS

We publicly released an application called PLATIPUS (Publication Literature Analysis and Text Interaction Platform for User Studies) that allows researchers to interact with literature supplied by COVIDScholar via a visual analytics platform. This tool contains standard filtering capabilities based on authors, journals, high-level categories, and various research-specific details via natural language processing and dozens of customizable visualizations that dynamically update from a researcher's query.

RESULTS

PLATIPUS is available online and currently links to over 100,000 publications and is still growing. This application has the potential to transform how COVID-19 researchers use public literature to enable their research.

CONCLUSIONS

The PLATIPUS application provides the end user with a variety of ways to search, filter, and visualize over 100,00 COVID-19 publications.

Differentiating multisystem inflammatory syndrome in children: a single-centre retrospective cohort study

OBJECTIVE

Features of multisystem inflammatory syndrome in children (MIS-C) overlap with other febrile illnesses, hindering prompt and accurate diagnosis. The objectives of this study were to identify clinical and laboratory findings that distinguished MIS-C from febrile illnesses in which MIS-C was considered but ultimately excluded, and to examine the diseases that most often mimicked MIS-C in a tertiary medical centre.

STUDY DESIGN

We identified all children hospitalised with fever who were evaluated for MIS-C at our centre and compared clinical signs and symptoms, SARS-CoV-2 status and laboratory studies between those with and without MIS-C. Multivariable logistic LASSO (least absolute shrinkage and selection operator) regression was used to identify the most discriminative presenting features of MIS-C.

RESULTS

We identified 50 confirmed MIS-C cases (MIS-C⁺) and 68 children evaluated for, but ultimately not diagnosed with, MIS-C (MIS-C^-). In univariable analysis, conjunctivitis, abdominal pain, fatigue, hypoxaemia, tachypnoea and hypotension at presentation were significantly more common among MIS-C⁺ patients. MIS-C⁺ and MIS-C^- patients had similar elevations in C-reactive protein (CRP), but were differentiated by thrombocytopenia, lymphopenia, and elevated ferritin, neutrophil/lymphocyte ratio, BNP and troponin. In multivariable analysis, predictors of MIS-C included age, neutrophil/lymphocyte ratio, platelets, conjunctivitis, oral mucosa changes, abdominal pain and hypotension.

CONCLUSIONS

Among hospitalised children undergoing evaluation for MIS-C, children with MIS-C were older, more likely to present with conjunctivitis, oral mucosa changes, abdominal pain and hypotension, and had higher neutrophil/lymphocyte ratios and lower platelet counts. These data may be helpful for discrimination of MIS-C from other febrile illnesses, including bacterial lymphadenitis and acute viral infection, with overlapping features.

Retropharyngeal Edema and Neck Pain in Multisystem Inflammatory Syndrome in Children (MIS-c)

We defined the prevalence of neck pain, trismus, or dysphagia (28.4%) and retropharyngeal edema (2.9%) among 137 patients with multisystem inflammatory syndrome in children (MIS-c). Retropharyngeal edema or phlegmon has been documented radiologically in at least 9 children. Symptoms of neck inflammation are common in MIS-c.

Similarities and Differences Between COVID-19-Related Multisystem Inflammatory Syndrome in Children and Kawasaki Disease

In December 2019, the first case of coronavirus disease (COVID-19) was first reported in Wuhan, China. As of March 2021, there were more than 120 million confirmed cases of COVID-19 and 2.7 million deaths. The COVID-19 mortality rate in adults is around 1-5%, and only a small proportion of children requires hospitalization and intensive care. Recently, an increasing number of COVID-19 cases in children have been associated with a new multisystem inflammatory syndrome. Its clinical features and laboratory characteristics are similar to those of Kawasaki disease (KD), KD shock syndrome, and toxic shock syndrome. However, this new disorder has some distinct clinical features and laboratory characteristics. This condition, also known as multisystem inflammatory syndrome in children (MIS-C) associated with COVID-19, has been observed mostly in Europe and the United States. This emerging phenomenon has raised the question of whether this disorder is KD triggered by SARS-CoV-2 or a syndrome characterized by multisystem inflammation that mimics KD. This narrative review is to discuss the differences between MIS-C and KD with the aim of increasing pediatricians' awareness of this new condition and guide them in the process of differential diagnosis.

Multisystem inflammatory syndrome in children with COVID-19

BACKGROUND

Multisystem inflammatory syndrome in children (MIS-C) is a dangerous pediatric complication of COVID-19.

OBJECTIVE

The purpose of this review article is to provide a summary of the diagnosis and management of MIS-C with a focus on management in the acute care setting.

DISCUSSION

MIS-C is an inflammatory syndrome which can affect nearly any organ system. The most common symptoms are fever and gastrointestinal symptoms, though neurologic and dermatologic findings are also well-described. The diagnosis includes a combination of clinical and laboratory testing. Patients with MIS-C will often have elevated inflammatory markers and may have an abnormal electrocardiogram or echocardiogram. Initial treatment involves resuscitation with careful assessment for cardiac versus vasodilatory shock using point-of-care ultrasound. Treatment should include intravenous immunoglobulin, anticoagulation, and consideration of corticosteroids. Interleukin-1 and/or interleukin-6 blockade may be considered for refractory cases. Aspirin is recommended if there is thrombocytosis or Kawasaki disease-like features on echocardiogram. Patients will generally require admission to an intensive care unit.

CONCLUSION

MIS-C is a condition associated with morbidity and mortality that is increasingly recognized as a potential complication in pediatric patients with COVID-19. It is important for emergency clinicians to know how to diagnose and treat this disorder.

The Great Gut Mimicker: A case report of MIS-C and appendicitis clinical presentation overlap in a teenage patient

BACKGROUND

Abdominal pain and other gastrointestinal symptoms are common presenting features of multisystem inflammatory syndrome in children (MIS-C) and can overlap with infectious or inflammatory abdominal conditions, making accurate diagnosis challenging.

CASE PRESENTATION

We describe the case of a 16-year-old female who presented with clinical symptoms suggestive of appendicitis and an abdominal computed tomography (CT) that revealed features concerning for appendicitis. After laparoscopic appendectomy, histopathology of the appendix demonstrated only mild serosal inflammation and was not consistent with acute appendicitis. Her overall clinical presentation was felt to be consistent with MIS-C and she subsequently improved with immunomodulatory and steroid treatment.

CONCLUSIONS

We note that MIS-C can mimic acute appendicitis. This case highlights MIS-C as a cause of abdominal imaging with features concerning for appendicitis, and MIS-C should be considered in the differential for a patient with appendicitis-like symptoms and a positive COVID-19 IgG. Lab criteria, specifically low-normal white blood cell count and thrombocytopenia, appears to be of high relevance in differing MIS-C from acute appendicitis, even when appendix radiologically is dilated.

Testing for and identification of Multisystem Inflammatory Syndrome in children in the pediatric emergency department

PURPOSE OF REVIEW

The current article summarizes updates on multisystem inflammatory syndrome in children (MIS-C) research and focuses on strategies to diagnose and manage these patients in the emergency department.

RECENT FINDINGS

MIS-C is an inflammatory syndrome that occurs approximately 4-5 weeks after severe acute respiratory syndrome coronavirus 2 infection. It is associated with symptoms such as fever, shock, abdominal pain, rash, and conjunctivitis along with laboratory abnormalities such as elevated inflammatory markers, coagulation factors, and cytokines. Patients fall into the following three subcategories: first, classic or incomplete Kawasaki; second, cardiogenic or distributive shock; or third, an inflammatory response that does not initially meet criteria of the other subcategories. Immediate treatment largely focuses on supportive care through fluid resuscitation and pressor support; however, inpatient management may also include intravenous immunoglobulin, steroids, anticoagulation and at times anti-inflammatory biologics.

SUMMARY

Overall fatality rate remains low and short-term research has demonstrated self-limited sequelae. Pediatricians should focus on the timely diagnosis and identification of this inflammatory disease via clinical findings and laboratory evidence to best treat these patients.

Systemic Inflammation and COVID-19 Mortality in Patients with Major Noncommunicable Diseases: Chronic Coronary Syndromes, Diabetes and Obesity

COVID-19 is currently considered an inflammatory disease affecting the entire organism. In severe forms, an augmented inflammatory response leads to the fulminant “cytokine storm”, which may result in severe multisystemic end-organ damage. Apart from the acute inflammatory response, it seems that chronic inflammation also plays a major role in the clinical evolution of COVID-19 patients. Pre-existing inflammatory conditions, such as those associated with chronic coronary diseases, type 2 diabetes mellitus or obesity, may be associated with worse clinical outcomes in the context of COVID-19 disease. These comorbidities are reported as powerful predictors of poor outcomes and death following COVID-19 disease. Moreover, in the context of chronic coronary syndrome, the cytokine storm triggered by SARS-CoV-2 infection may favor vulnerabilization and rupture of a silent atheromatous plaque, with consequent acute coronary syndrome, leading to a sudden deterioration of the clinical condition of the patient. This review aims to present the current status of knowledge regarding the link between COVID-19 mortality, systemic inflammation and several major diseases associated with poor outcomes, such as cardiovascular diseases, diabetes and obesity.