A recently explored aspect of the iceberg named COVID-19: multisystem inflammatory syndrome in children (MIS-C)

Differentiating Multisystem Inflammatory Syndrome in Children from Kawasaki Disease During the Pandemic

OBJECTIVE

We aimed to delineate the distinctive characteristics that aid in distinguishing between Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C) with KD-like manifestations during the pandemic.

MATERIALS AND METHODS

We evaluated KD patients and MIS-C patients with KD-like symptoms admitted during the pandemic (between January 2021 and December 2022).

RESULTS

Thirty-three MIS-C patients and 15 KD patients were included. Kawasaki disease patients were younger than MIS-C patients (3.4 vs. 7.6 years). Rash (P = .044, 100% vs. 75.7%), oral mucosal changes (P = .044, 100% vs. 75.7%), and cervical lymphadenopathy (P = .001, 93.3% vs. 42.4%) were more common in KD. Multisystem inflammatory syndrome in children: patients had more hypotension (P = .002, 45.4% vs. 0), gastrointestinal (P .001, 72.7% vs. 13.3%), and respiratory symptoms (P = .044, 24.2% vs. 0). Multisystem inflammatory syndrome in children patients also had low lymphocyte and thrombocyte counts and elevated levels of d-dimer, ferritin, and cardiac parameters, unlike KD patients. Multisystem inflammatory syndrome in children patients exhibited a notable reduction in left ventricular systolic function in echocardiography. Another significant difference with regard to management was the anakinra treatment, which was prescribed for MIS-C patients.

CONCLUSION

Although MIS-C patients might display a clinical resemblance to KD, several features could help differentiate between MIS-C and classical KD. Specific clinical (hypotension, gastrointestinal, and respiratory symptoms) and laboratory (low lymphocyte and thrombocyte counts with higher C-reactive protein, ferritin, d-dimer, and cardiac parameters) features are characteristic of MIS-C. In addition, divergence in management strategies is evident between the 2 diseases, as biologic drugs were more prevalently employed in MIS-C patients than in classical KD patients.

Evaluation of 601 children with multisystem inflammatory syndrome (Turk MISC study)

PURPOSE

Due to its link with the 2019 coronavirus, the multisystem inflammatory syndrome in children (MISC) has garnered considerable international interest. The aim of this study, in which MISC patients were evaluated multicenter, and the data of the third period of the Turk-MISC study group, to compare the clinical and laboratory characteristics and outcomes of MISC patients who did and did not require admission to an intensive care unit (ICU).

METHODS

This retrospective multicenter observational study was carried out between June 11, 2021, and January 01, 2022. The demographics, complaints, laboratory results, system involvements, and outcomes of the patients were documented.

RESULTS

A total of 601 patients were enrolled; 157 patients (26.1%) required hospitalization in the intensive care unit (ICU). Median age was 8 years (interquartile range (IQR) 4.5-11.3 years. The proportion of Kawasaki disease-like features in the ICU group was significantly higher than in the non-ICU group (56.1% vs. 43.2% p = 0.006). The ICU group had considerably lower counts of both lymphocytes and platelets (lymphocyte count 900 vs. 1280 cells × μL, platelet count 153 vs. 212 cells × 103/ μL, all for p< 0.001). C-reactive protein, procalcitonin, and ferritin levels were significantly higher in the ICU group (CRP 164 vs. 129 mg/L, procalcitonin 9.2 vs. 2.2 μg/L, ferritin 644 vs. 334 μg/L, all for p< 0.001). Being between ages 5-12 and older than 12 increased the likelihood of hospitalization in the ICU by four [95% confidence intervals (CI)1.971-8.627] and six times (95% CI 2.575-14.654), respectively, compared to being between the ages 0-5. A one-unit increase in log D-dimer (µg/L) and log troponin (ng/L) was also demonstrated to increase the need for intensive care by 1.8 (95% CI 1.079-3.233) and 1.4 times (95% CI 1.133-1.789), respectively.     Conclusion: By comparing this study to our other studies, we found that the median age of MISC patients has been rising. Patients requiring an ICU stay had considerably higher levels of procalcitonin, CRP, and ferritin but significantly lower levels of lymphocyte and thrombocyte. In particular, high levels of procalcitonin in the serum might serve as a valuable laboratory marker for anticipating the need for intensive care.

WHAT IS KNOWN

• Lymphopenia and thrombocytopenia were an independent predictor factors in patients with MISC who needed to stay in intensive care unit. • The possibility of the need to stay in the intensive care unit in patients with MISC who had Kawasaki disease-like findings was controversial compared with those who did not.

WHAT IS NEW

• A one-unit increase log D dimer and log troponin was demonstrated to require for intensive care unit by 1.8 and 1.4 times, respectively. • Serum procalcitonin levels had the best performance to predict stay in the intensive care unit stay.

Readmission reasons of pediatric patients diagnosed with multisystem inflammatory syndrome after discharge

Objectives

There is no clear information in the literature about causes of reactivation of multisystem inflammatory syndrome in children (MIS-C) or indications for readmissions for MIS-C after discharge; as a result, the conditions that may develop after infection in children with MIS-C were discussed, and the reasons for hospitalization were screened.

Patients and methods

This single-center retrospective study was conducted with 95 patients (65 males, 30 females; mean age: 92.8±55.5 months; range, 5 to 17 months) between November 11, 2020, and December 30, 2021. Children who were rehospitalized in the study center after their discharge with the diagnosis of MIS-C were included in the study, and the indications for readmissions were evaluated.

Results

During the study period, six (6.3%) patients (4 males, 2 females; median age: 114.5 months [interquartile range: 122 months]) had to be rehospitalized. Four of these patients had an underlying disease, while the other two were previously healthy children. Fever was the most common reason for readmissions in half of the patients, while the remaining patients were readmitted with the indications of myocarditis, pneumonia, and posttraumatic pain syndrome.

Conclusion

Although no evidence for the reactivation of MIS-C was detected in patients in the literature, it should also be emphasized that close follow-up of these patients is a must, considering possible cardiac complications.

Coronavirus disease 2019-related Kawasaki syndrome: a case report

BACKGROUND

Coronavirus disease 2019 has changed the pattern of some diseases in the world, especially in pediatrics. Despite data suggesting that the pediatric population is less affected by coronavirus disease-19 infection, new concerns have been raised owing to reported cases with hyperinflammatory conditions such as Kawasaki disease.

CASE PRESENTATION

We report herein the case of a pediatric patient diagnosed and treated for classic Kawasaki disease in the setting of confirmed coronavirus disease 2019 infection. She was an 8-year-old, previously healthy, and fully immunized Iranian girl who initially presented to the pediatric emergency department with 5 days of intermittent fever, followed by abdominal pain, nausea, and vomiting. She was admitted for fever and abdominal pain to the surgery service of Akbar Hospital with suspected appendicitis.

CONCLUSIONS

This case report may serve as a useful reference to other clinicians caring for pediatric patients affected by coronavirus disease 2019 infection. Standard therapeutic interventions for Kawasaki disease must be performed to prevent critical coronary aneurysm-related complications in the coronavirus disease 2019 era.

Multisystem Inflammatory Syndrome and Autoimmune Diseases Following COVID-19: Molecular Mechanisms and Therapeutic Opportunities

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2), has led to huge concern worldwide. Some SARS-CoV-2 infected patients may experience post–COVID-19 complications such as multisystem inflammatory syndrome, defined by symptoms including fever and elevated inflammatory markers (such as elevation of C reactive protein (CRP), erythrocyte sedimentation rate, fibrinogen, procalcitonin test, D-dimer, ferritin, lactate dehydrogenase or IL-6, presence of neutrophilia, lymphopenia, decreased albumin, and multiple organ dysfunction). Post–COVID-19 complications may also manifest as autoimmune diseases such as Guillain-Barré syndrome and systemic lupus erythematosus. Signaling disorders, increased inflammatory cytokines secretion, corticosteroid use to treat COVID-19 patients, or impaired immune responses are suggested causes of autoimmune diseases in these patients. In this review, we discuss the molecular and pathophysiological mechanisms and therapeutic opportunities for multisystem inflammatory syndrome and autoimmune diseases following SARS-CoV-2 infection with the aim to provide a clear view for health care providers and researchers.

Early experience of COVID-19 vaccine-related adverse events among adolescents and young adults with rheumatic diseases: A single-center study

OBJECTIVE

Considering the concerns regarding the coronavirus disease-2019 (COVID-19) vaccine safety among pediatric patients with inflammatory rheumatic diseases (IRD) due to a lack of data, an urgent need for studies evaluating safety profiles of vaccines emerged.

METHODS

Among participants vaccinated by CoronaVac inactive SARS-CoV-2 or BNT162b2 messenger RNA (mRNA) COVID-19 (Pfizer-BioNTech) vaccine, healthy children under 18 and patients under 21 with an at least 1-year follow-up period in our department for a childhood-onset rheumatic disease were included into this cross-sectional study.

RESULTS

Overall, 246 subjects (141 [57.3%] females) (biologic group: 43, non-biologic group: 180, healthy control group: 23) were eligible for the study. The median age was 15.34 (12.02-20.92) years. The most common adverse events were fatigue (n = 68, 27.6%), headache (n = 44, 17.9%), myalgia (n = 38, 15.4%), arthralgia (n = 38, 15.4%), and fever (n = 35, 14.2%). Only 3 subjects (2 patients with familial Mediterranean fever, and one healthy child) were considered to experienced serious adverse events, since they required hospitalization. Local reactions were seen in 20 (8.13%), and 27 patients (12.1%) had disease flares within 1 month after the vaccines. Although it was significantly higher in those who received the BNT162b2 mRNA vaccine (P < .001), there was no significant relationship between adverse event frequency and age, gender, the existing diseases, ongoing treatment regimens and pre-vaccination COVID-19 histories.

CONCLUSION

Although immunogenicity studies for efficacy of the vaccines and long-term follow-up studies for adverse events monitoring are required, our study indicates an acceptable safety profile of COVID-19 vaccines and encourages children with IRD to be vaccinated.

Inborn errors of metabolism and coronavirus disease 2019: Evaluation of the metabolic outcome

BACKGROUND

Infectious diseases can result in a catabolic state and possibly trigger an acute metabolic decompensation in inborn errors of metabolism (IEM), which could be life threatening. Studies regarding the course of severe acute respiratory syndrome coronavirus 2 infections in patients with IEM are generally limited to case reports. Here, we aimed to evaluate the clinical findings of coronavirus disease 2019 (COVID-19) and describe the impact of severe acute respiratory syndrome coronavirus 2 infections on metabolic outcomes in IEM patients.

METHODS

Patients who were diagnosed with different types of IEM and developed microbiologically confirmed COVID-19 infection were included. Clinical findings and laboratory results were recorded retrospectively in terms of both IEM and COVID-19.

RESULTS

Eleven patients with diagnosis of intoxication type metabolic disorders, five patients with energy metabolism disorders, and six patients with complex molecular disorders were enrolled. The most frequent clinical finding was fever (52.1%) followed by fatigue/myalgia (47.8%). None of the patients was younger than 1 year. None of the patients presented severe or critical disease. In terms of metabolic decompensation, two patients diagnosed with propionic acidemia, one patient with methylmalonic acidemia and one patient with 3-hydroxy-3-methylglutaryl-CoA lyase deficiency presented clinical and biochemical findings of an acute metabolic attack.

CONCLUSIONS

Based on our results, IEM are not found to be an additional risk factor for severe COVID-19 infection. However, patients with intoxication type and energy metabolism disorders should be considered as a vulnerable population for COVID-19 and have a major risk of developing acute metabolic decompensation that can lead to life-threatening complications.

Is It Stevens-Johnson Syndrome or MIS-C with Mucocutaneous Involvement?

Background

Severe acute respiratory syndrome coronavirus-2 (SARS-COV-2) can be present in the form of multisystem inflammatory disease in children. Case Presentation. A 25-month-old boy presented with fever, malaise, diffuse maculopapular rashes, and mucosal involvement during the COVID-19 pandemic. He was first diagnosed with Stevens-Johnson syndrome (SJS). Further evaluation revealed lymphopenia, thrombocytopenia, and elevated levels of C-reactive protein (CRP), ferritin, and fibrinogen. This was followed by a positive polymerase chain reaction (PCR) test for COVID-19. In addition to receiving initial care for SJS, he was treated for MIS-C, which led to his recovery after four days.

Conclusion

COVID-19 infection should be considered in children with fever and dermatological features during the pandemic because it may cause different features of the multisystem inflammatory syndrome in children (MIS-C), suggestive of delayed hyperimmune response.

Prevalence of paediatric hyperinflammatory conditions in paediatric and adolescent hospitalized COVID-19 patients: a systematic review and meta-analysis

In the milieu of coronavirus disease 2019 (COVID-19), there are increasing reports of paediatric hyperinflammatory conditions (PHICs), including multisystem inflammatory syndrome in children (MIS-C), paediatric multisystem inflammatory syndrome temporally associated with SARS-CoV-2 (PIMS-TS) and Kawasaki disease (KD). Few analyses of PHIC prevalence in paediatric and adolescent hospitalized COVID-19 patients exist. The purpose of this study was to perform a meta-analysis to determine a pooled prevalence estimate of PHICs in paediatric and adolescent hospitalized patients admitted for treatment due to COVID-19. Individual studies were retrieved from PubMed/Medline, EMBASE and Cochrane databases. Relevant prevalence, baseline, treatment and outcome data were extracted using a standardized datasheet. The systematic review and meta-analysis were conducted as per the PRISMA and MOOSE guidelines. Overall, 14 studies with 2202 patients admitted for treatment due to COVID-19, among whom 780 were diagnosed with PHICs, were included. The crude estimate of prevalence was 35.42%, and the pooled estimate of prevalence was 29% (random pooled ES = 0.29; 95% CIs = 0.18-0.42; p < 0.0001; z = 7.45). A sizeable proportion of paediatric and adolescent hospitalized patients admitted for treatment due to COVID-19 are diagnosed with a PHIC warranting a high index of clinical suspicion for PHICs. Further studies are required to validate these findings.

COVID-19: potential therapeutics for pediatric patients

The global spread of COVID-19 has imparted significant economic, medical, and social burdens. Like adults, children are affected by this pandemic. However, milder clinical symptoms are often experienced by them. Only a minimal proportion of the affected patients may develop severe and complicated COVID-19. Supportive treatment is recommended in all patients. Antiviral and immunomodulatory medications are spared for hospitalized children with respiratory distress or severe to critical disease. Up till now, remdesivir is the only USFDA-approved anti-COVID-19 medication indicated in the majority of symptomatic patients with moderate to severe disease. Dexamethasone is solely recommended in patients with respiratory distress maintained on oxygen or ventilatory support. The use of these medications in pediatric patients is founded on evidence deriving from adult studies. No randomized controlled trials (RCTs) involving pediatric COVID-19 patients have assessed these medications' efficacy and safety, among others. Similarly, three novel monoclonal anti-SARS-CoV-2 spike protein antibodies, bamlanivimab, casirivimab and imdevimab, have been recently authorized by the USFDA. Nonetheless, their efficacy has not been demonstrated by multiple RCTs. In this review, we aim to dissect the various potential therapeutics used in children with COVID-19. We aspire to provide a comprehensive review of the available evidence and display the mechanisms of action and the pharmacokinetic properties of the studied therapeutics. Our review offers an efficient and practical guide for treating children with COVID-19.

Clinical features and outcomes of 76 patients with COVID-19-related multi-system inflammatory syndrome in children

Objectives

Multi-system inflammatory syndrome in children (MIS-C) is a less understood and a rare complication of coronavirus disease-2019 (COVID-19). Given the scarce data regarding this novel disease, we aimed to describe the clinical features and outcomes of our patients with MIS-C and to evaluate the associated factors for the pediatric intensive care unit (PICU) admission.

Methods

The MIS-C patients under 18 years old diagnosed and treated in three referral centers between July 2020 and March 2021 were included. Data of the patients were retrospectively obtained from their medical records.

Results

Overall, 76 subjects (24 females) with a mean age of 8.17 ± 4.42 years were enrolled. Twenty-seven (35.5%) patients were admitted to the PICUs. The two most common systemic involvement patterns were cardiac and gastrointestinal. There was only one lethal outcome in a patient with underlying acute lymphoblastic leukemia. Those with higher procalcitonin levels at admission were found to stay longer in the hospital (r = 0.254, p = 0.027). The risk of PICU admission increased with age (aOR: 1.277; 95% CI: 1.089–1.498; p = 0.003) and with decreased initial serum albumin levels (aOR: 0.105; 95% CI: 0.029–0.378; p = 0.001).

Conclusion

Although there is a wide clinical variability among the patients with MIS-C, we suggest that those with older age and lower initial serum albumin levels merit close monitoring due to their higher risk for PICU admission.

Key Points • Although there is a wide variability regarding the management process among clinicians, MIS-C is a rare, severe, less understood complication of COVID-19 that may cause rapid clinical deterioration in the patients. • Clinicians should be aware of this condition in children with persistent fever and a family history of COVID-19. • Older age and low serum albumin levels are the independent predictors for the pediatric intensive care unit admission among MIS-C patients.

Multisystemic inflammatory syndrome in children associated with COVID-19: a single center experience in Turkey

OBJECTIVE

Multisystem inflammatory syndrome in children (MIS-C) associated with the coronavirus disease 2019 (COVID-19) is a new concern emerging as a severe presentation of COVID-19 in children. We aimed to describe the characteristics and short-term outcomes of children diagnosed with MIS-C.

MATERIAL AND METHODS

A retrospective study was conducted on 24 patients who were diagnosed with MIS-C between June 1, 2020 and December 1, 2020. A total of 24 (14 male and 10 female) patients were included in the study.

RESULTS

The median age at the diagnosis was 111 (10-180) months. A total of 17 patients had a history of contact with a patient with COVID-19. Among the 24 patients, the most common findings were gastrointestinal involvement (n=20), followed by conjunctivitis (n=12), erythematous rash (n=11), and oral changes (n=10). Cardiovascular involvement was detected in 12 patients, of whom six had systolic dysfunction, four had mild coronary artery involvement, four had pericardial effusion, and three had mitral insufficiency. All patients received intravenous immunoglobulin, and 14 patients were treated with methylprednisolone in addition. Anti-interleukin-1 was given to two patients. The median duration of hospitalization was 8 (5-15) days. A total of 23 patients were discharged and evaluated on the median of 68.5 (52-140) days after discharge. The remaining one patient with dilated cardiomyopathy died after 2 months in the intensive care unit.

CONCLUSION

Increasing the knowledge on MIS-C will provide clinicians with information on early recognition, evaluation, and management of these patients.

Multisystemic inflammatory syndrome in children associated with COVID-19: a single center experience in Turkey

Objective

Multisystem inflammatory syndrome in children (MIS-C) associated with the coronavirus disease 2019 (COVID-19) is a new concern emerging as a severe presentation of COVID-19 in children. We aimed to describe the characteristics and short-term outcomes of children diagnosed with MIS-C.

Material and Methods

A retrospective study was conducted on 24 patients who were diagnosed with MIS-C between June 1, 2020 and December 1, 2020. A total of 24 (14 male and 10 female) patients were included in the study.

Results

The median age at the diagnosis was 111 (10-180) months. A total of 17 patients had a history of contact with a patient with COVID-19. Among the 24 patients, the most common findings were gastrointestinal involvement (n=20), followed by conjunctivitis (n=12), erythematous rash (n=11), and oral changes (n=10). Cardiovascular involvement was detected in 12 patients, of whom six had systolic dysfunction, four had mild coronary artery involvement, four had pericardial effusion, and three had mitral insufficiency. All patients received intravenous immunoglobulin, and 14 patients were treated with methylprednisolone in addition. Anti-interleukin-1 was given to two patients. The median duration of hospitalization was 8 (5-15) days. A total of 23 patients were discharged and evaluated on the median of 68.5 (52-140) days after discharge. The remaining one patient with dilated cardiomyopathy died after 2 months in the intensive care unit.

Conclusion

Increasing the knowledge on MIS-C will provide clinicians with information on early recognition, evaluation, and management of these patients.

Kawasaki Disease Shock Syndrome in Japan and Comparison With Multisystem Inflammatory Syndrome in Children in European countries

Multisystem inflammatory syndrome in children (MIS-C) is a severe Kawasaki-like illness that was first linked to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in European countries in the spring of 2020 and has been suggested to have overlap with Kawasaki disease shock syndrome (KDSS). There are few reports of MIS-C from Asia. This observational study aimed to identify the clinical features in children presenting with KDSS in Japan over a 5-year period and to summarize similarities and differences between KDSS and MIS-C. We retrospectively collected data on patient characteristics, clinical signs and symptoms, treatment, and prognosis including coronary artery abnormalities (CAAs), which were compared with data of patients with KDSS worldwide and patients with MIS-C from a review. KDSS was identified in 6 (1.1%) of 552 patients with Kawasaki disease (KD) treated at a single institution in Japan between 2015 and 2020 (1 in 2020). In patients with KDSS in Japan or worldwide vs. patients with MIS-C, KDSS was more likely to have a diagnosis of complete KD (100, 70 vs. 6.3%), a higher incidence of CAAs (50, 65 vs. 11%), and a greater requirement for vasoactive agonists (67, 67 vs. 43%) because of circulatory shock (100, 50 vs. 26%). Both KDSS and MIS-C had good prognosis (mortality 0, 6.7 vs. 1.7%). Although KDSS in Japan and MIS-C show some overlap in clinical symptoms, they are unlikely to be the same disease entity. KDSS is more likely to have a cardiovascular phenotype with CAAs and requires treatment with cardiovascular agents.

Characteristics of Children With Kawasaki Disease-Like Signs in COVID-19 Pandemic: A Systematic Review

Recent studies have shown that several children diagnosed with COVID-19 have developed Kawasaki Disease (KD)-like symptoms. This systematic review aims to assess the demographic, laboratory, and clinical characteristics of children with KD-like syndrome during the COVID-19 pandemic and evaluate efficacy of treatments and patients' outcome. A comprehensive search was carried out systematically through PubMed, Scopus, and Web of Science (WoS), medRxiv, and bioRxiv by two reviewers independently for all studies or preprints data on the demographic, laboratory, and clinical characteristics of children with K.D-like signs during the COVID-19 outbreak. Overall, 378 studies were identified by the systematic search, of which 25 studies were included in the study. The included studies involved 599 patients in total. Thirteen studies (52%) were case reports or case series, and the rest (48%) were cohort studies. In 19 studies, patients were diagnosed with Multisystem inflammatory syndrome in children (MIS-C). In 16 studies COVID-19 was diagnosed in all patients based on their polymerase chain reaction result, serological findings, and computed tomography results. Higher C-reactive protein and erythrocyte sedimentation rate level were the most prevalent laboratory findings. In most studies, patients had leucopenia with marked lymphopenia, hypoalbuminemia, and increased ferritin, as well as hyponatremia. Abnormal echocardiography and respiratory outcomes were the most common clinical outcomes. In 11 studies, all patients required intensive care unit admission. Findings of the present systematic review show that the incidence of KD-like syndrome in the COVID-19 pandemic increased significantly. Moreover, this study offers new insights in the KD-like syndrome pathogenesis and clinical spectrum during COVID-19 pandemic.

A 6-Year-Old Boy with COVID-19-Positive Pleural Effusion and Kawasaki-Like Features

The ongoing outbreak of the novel coronavirus (SARS-CoV-2) has exposed many pediatric patients from around the world to coronavirus disease. Although pleural effusions are classified as atypical features of COVID-19 infection, we report a 6-year-old boy who had a positive IgG antibody ELISA test for COVID-19 and presented with respiratory distress, bilateral pleural effusions, and signs and symptoms of multisystem inflammatory syndrome. The RT-PCR test of the pleural fluid specimen was positive for novel coronavirus. To our knowledge, this is the first pediatric report of a COVID-19-positive pleural fluid.

Distinguishing Between Multisystem Inflammatory Syndrome, Associated With COVID-19 in Children and the Kawasaki Disease: Development of Preliminary Criteria Based on the Data of the Retrospective Multicenter Cohort Study

Objectives: Diagnostic between multisystem inflammatory syndrome associated with COVID-19 in children (MIS-C) and Kawasaki disease (KD) can make difficulties due to many similarities. Our study aimed to create a Kawasaki/MIS-C differentiation score (KMDscore) allowing discrimination of MIS-C and KD. Study design: The retrospective multicenter cohort study included clinical, laboratory, and instrumental information about MIS-C (n = 72) and KD (n = 147). The variables allowed to discriminate both conditions used to construct and validate the diagnostic score called the KMDscore. Results: Patients with MIS-C were older, had earlier admission to the hospital, had a shorter time before fever resolution, two times frequently had signs of GI and CNS involvement observed, and had more impressive thrombocytopenia, higher level of CRP, ferritin, ALT, AST, LDH, creatinine, triglycerides, troponin, and D-dimer compared to KD patients. Respiratory signs in MIS-C were presented with pleuritis, acute respiratory distress syndrome, oxygen dependency, lung infiltration, and ground-glass opacities in CT. The heart involvement with fast progression of myocarditis provided the severity of MIS-C and ICU admission due to 12 times higher arterial hypotension or shock and required cardiotonic. No differences in the frequency of CA lesions were seen in the majority of cases. Five criteria, CRP >11 mg/dl (18 points), D-dimer >607 ng/ml (27 points), age >5 years (30 points), thrombocytopenia (25 points), and GI involvement (28 points), were included in the KMDscore. The summa >55 points allowed to discriminate MIS-C from KD with a sensitivity of 87.5% and specificity of 89.1%. Conclusion: The KMDscore can be used to differentiate the diagnostic of MIS-C from KD.

Hematuria as an Early Sign of Multisystem Inflammatory Syndrome in Children: A Case Report of a Boy With Multiple Comorbidities and Review of Literature

Introduction: While the clinical course of SARS-CoV-2 infection seems to be milder or asymptomatic within the pediatric population, growing attention has been laid to the rare complication elicited by virus, multisystem inflammatory syndrome in children temporarily associated with COVID-19 (MIS-C). Published definition and criteria of MIS-C include persistent fever, multisystem involvement, and elevated markers of inflammation, without obvious microbial inflammation or other plausible diagnosis. However, the aim of this case report is to emphasize the diversity of symptoms of MIS-C, beyond the defined criteria. Case Presentation: We present a 10-year-old boy with 8p23.1 microdeletion syndrome and multiple comorbidities who initially came to our attention due to hematuria, persistent fever, rash, and elevated markers of inflammation. Within the next 2 days, his condition worsened despite the broad-spectrum antibiotic therapy. Assuming his past history of SARS-CoV-2 exposure, MIS-C was suspected. A high level of clinical suspicion was further supported by significant clinical features (vomiting, abdominal pain, conjunctivitis, arrhythmia, and mild left ventricular systolic dysfunction with pleural effusion) along with laboratory findings (elevated ESR, CRP, proBNP, D-dimers and fibrinogen, positive IgG SARS-CoV-2 antibodies, and negative microbiological cultures). The patient was given intravenous immunoglobulin (IVIG) and began to show instantaneous clinical and laboratory improvement. Conclusion: Despite numerous reports of MIS-C cases in children, there are still many uncertainties regarding the clinical presentation and laboratory findings, as well as mechanisms beyond this intriguing disorder. In our case, for the first time hematuria is reported as an early symptom of MIS-C. We strongly believe that reporting various manifestations and outcomes in MIS-C patients will lead to improved diagnosis, treatment, and overall understanding of this novel inflammatory condition.

Case Report: Necrotizing Stomatitis as a Manifestation of COVID-19-Associated Vasculopathy

Necrotizing stomatitis is a rare, acute-onset disease that is usually associated with severely malnourished children or diminished systemic resistance. We describe a 1-year-old girl who developed necrotizing stomatitis, vasculitic rash, skin desquamation on the fingers and toes, and persistent hypertension after serologically confirmed SARS-CoV-2 infection. Her laboratory investigations revealed positive IgG anticardiolipin and IgG anti-β2 glycoprotein antibodies, and biopsy of the mucosa of the lower jaw showed necrosis and endothelial damage with mural thrombi. Swollen endothelial cells of small veins in the upper dermis were confirmed also by electron microscopy. As illustrated by our case, necrotizing stomatitis may develop as a rare complication associated with SARS-CoV-2 infection and can be considered as a part of the clinical spectrum of COVID-19 vasculopathy. The pathogenic mechanism could involve a consequence of inflammatory events with vasculopathy, hypercoagulability, and damage of endothelial cells as a response to SARS-CoV-2 infection.

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.