Non-SARS-CoV-2 Infections Among Patients Evaluated for MIS-C Associated With COVID-19

Elevated risk for psychiatric outcomes in pediatric patients with Multisystem Inflammatory Syndrome (MIS-C): A review of neuroinflammatory and psychosocial stressors

Multisystem Inflammatory Syndrome in Children (MIS-C) is a secondary immune manifestation of COVID-19 involving multiple organ systems in the body, resulting in fever, skin rash, abdominal pain, nausea, shock, and cardiac dysfunction that often lead to hospitalization. Although many of these symptoms resolve following anti-inflammatory treatment, the long-term neurological and psychiatric sequelae of MIS-C are unknown. In this review, we will summarize two domains of the MIS-C disease course, 1) Neuroinflammation in the MIS-C brain and 2) Psychosocial disruptions resulting from stress and hospitalization. In both domains, we present existing clinical findings and hypothesize potential connections to psychiatric outcomes. This is the first review to conceptualize a holistic framework of psychiatric risk in MIS-C patients that includes neuroinflammatory and psychosocial risk factors. As cases of severe COVID-19 and MIS-C subside, it is important for clinicians to monitor outcomes in this vulnerable patient population.

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.

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.

Current Insights Into the Pathophysiology of Multisystem Inflammatory Syndrome in Children

Purpose of Review

We highlight the new clinical entity multisystem inflammatory syndrome in children (MIS-C), the progress in understanding its immunopathogenesis, and compare and contrast the clinical and immunologic features of MIS-C with Kawasaki disease (KD).

Recent Findings

Studies show immune dysregulation in MIS-C including T lymphocyte depletion and activation, T cell receptor Vbeta skewing, elevated plasmablast frequencies, increased markers of vascular pathology, and decreased numbers and functional profiles of antigen-presenting cells.

Summary

MIS-C is a late manifestation of infection with SARS-CoV-2 associated with marked immune activation and many potential mechanisms of immunopathogenesis. MIS-C and KD have clinical similarities but are distinct. Myocardial dysfunction with or without mild coronary artery dilation can occur in MIS-C but generally corrects within weeks. In contrast, the coronary arteries are the primary target in KD, and coronary artery sequelae can be lifelong. Supportive care and anti-inflammatory therapy appear to hasten improvement in children with MIS-C, and there is hope that vaccines will prevent its development.

Clinical features of multisystem inflammatory syndrome in children

PURPOSE OF REVIEW

To review diagnosis, clinical characteristics and treatment of multisystem inflammatory syndrome in children (MIS-C) associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

RECENT FINDINGS

MIS-C emerged in spring 2020 as a hyperinflammatory syndrome following SARS-CoV-2 exposure in children. Despite growing awareness of MIS-C, diagnosis remains challenging due to the range of phenotypes and severity. Fever accompanied by shock, cardiac dysfunction, gastrointestinal symptoms, or mucocutaneous signs suggestive of Kawasaki disease, especially in the presence of known or suspected coronavirus disease 2019 exposure, should trigger consideration of MIS-C. However, clinical presentations are highly varied and may overlap with other infectious diseases. Clinicians must maintain a high index of suspicion for MIS-C and be aware that patients may develop coronary artery aneurysms and myocarditis even with few or no Kawasaki disease symptoms. More precise diagnostic criteria and specific biomarkers are needed to aid diagnosis. Intravenous immunoglobulin (IVIG) is first-line therapy, and steroids should be considered as initial adjunctive treatment for patients with severe manifestations or other risk factors. Prompt treatment is essential, as patients may worsen acutely, though overall prognosis is reassuring.

SUMMARY

MIS-C associated with SARS-CoV-2 has varied clinical manifestations. Clinicians must be aware of the common presentation and potential for decompensation and cardiac sequalae to guide appropriate evaluation and treatment.

The COVID trap: pediatric diagnostic errors in a pandemic world

OBJECTIVES

The COVID-19 pandemic has introduced strains in the diagnostic process through uncertainty in diagnosis, changes to usual clinical processes, and introduction of a unique social context of altered health care delivery and fear of the medical environment. These challenges created a context ripe for diagnostic error involving both systems and cognitive factors.

CASE PRESENTATION

We present a series of three pediatric cases presenting to care during the early phases of the COVID-19 pandemic that highlight the heightened potential for diagnostic errors in the pandemic context with particular focus on the interplay of systems and cognitive factors leading to delayed and missed diagnoses. These cases illustrate the particular power of availability bias, diagnostic momentum, and premature closure in the diagnostic process.

CONCLUSIONS

Through integrated commentary and a fishbone analysis of the cognitive and systems factors at play, these three cases emphasize the specific influence of the COVID-19 pandemic on pediatric patients.

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.

Ocular and Systemic Manifestations in Paediatric Multisystem Inflammatory Syndrome Associated with COVID-19

This study aimed to achieve a better understanding of the epidemiological and clinical characteristics of multisystem inflammatory syndrome in children (MIS-C) following coronavirus disease 2019 (COVID-19). We searched PubMed and Embase between December 2019 and March 2021 and included only peer-reviewed clinical studies or case series. The proportions of patients who had conjunctivitis, systemic symptoms/signs (s/s), Kawasaki disease (KD), and exposure history to suspected/confirmed COVID-19 cases were obtained. Moreover, positive rates of the nasopharyngeal real-time reverse transcriptase polymerase chain reaction (RT-PCR) and serum antibody for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were recorded. Overall, 32 studies with 1458 patients were included in the pooled analysis. Around half of the patients had conjunctivitis. The five most common systemic manifestations were fever (96.4%), gastrointestinal s/s (76.7%), shock (61.5%), rash (57.1%), and neurological s/s (36.8%). Almost one-third presented complete KD and about half had exposure history to COVID-19 cases. The positivity of the serology (82.2%) was higher than that of the nasopharyngeal RT-PCR (37.0%). MIS-C associated with COVID-19 leads to several features similar to KD. Epidemiological and laboratory findings suggest that post-infective immune dysregulation may play a predominant role. Further studies are crucial to elucidate the underlying pathogenesis.