Guideline for the diagnosis and treatment of incomplete Kawasaki disease in children in China.

BACKGROUND: Kawasaki disease (KD) is a pyretic ailment predominantly observed in children aged below 5 years. There is currently a dearth of precise markers for timely identification of incomplete Kawasaki disease (IKD). It is imperative to develop updated, comprehensive, and evidence-based guidelines to effectively direct clinical practice. METHODS: The guideline development group comprised individuals with diverse expertise in both content and methodology and carried out an extensive exploration of the following digital repositories: CNKI, VIP, Wanfang Data, UpToDate, BMJ, Clinical Evidence, National Guideline Clearinghouse, Joanna Briggs Institute Library, Cochrane Library, and PubMed. The entire period from the establishment of these databases until January 1, 2024 was covered. To evaluate IKD, systematic reviews and randomised controlled trials were assessed using the risk of prejudice instrument specified in the Cochrane Handbook, along with the evidence robustness framework established by the GRADE group. The recommendations were formulated based on the findings, considering the evidence strength. After several iterations of expert consensus, the relevant professional committees in China endorsed the ultimate guideline. RESULTS: These guidelines address clinical questions regarding the classification and definition of KD, diagnosis of IKD, treatment during the acute phase of IKD, and follow-up of IKD. CONCLUSIONS: To provide healthcare professionals with guidance and decision-making bases for the diagnosis and treatment of IKD in China, 13 recommendations were formulated based on expert consensus and evidence of best practices.

Kawasaki disease: patients' transition journey and recommendations for adult care.

BACKGROUND: Children who develop coronary artery aneurysms after Kawasaki disease are at risk for cardiovascular morbidity, requiring health care transition and lifelong follow-up with an adult specialist. Follow-up losses after health care transition have been reported but without outcome and patient experience evaluation. OBJECTIVE: The Theoretical Domains Framework underpinned our aim to explore the required self-care behaviours and experiences of young adults' post-health care transition. METHODS: A qualitative description approach was used for virtual, 1:1 interviews with 11 participants, recruited after health care transition from a regional cardiac centre in Ontario. Directed content analysis was employed. RESULTS: Health, psychosocial, and lifestyle challenges were compounded by a sense of loss. Six themes emerged within the Theoretical Domains Framework categories. Participants offered novel health care transition programme recommendations. CONCLUSIONS: The realities of health care transition involve multiple, overlapping stressors for young adults with Kawasaki disease and coronary artery aneurysms. Our findings will inform a renewed health care transition programme and will include outcome evaluation.

Thymic stromal lymphopoietin induces platelet mitophagy and promotes thrombosis in Kawasaki disease.

Kawasaki disease (KD) is an acute systemic vasculitis primarily affecting infants and children. Activated platelets predispose patients to coronary artery structural lesions that may lead to thrombotic cardiovascular events. To discover potential proteins underlying platelet activation in KD, we conducted a protein chip assay of 34 cytokines and discovered thymic stromal lymphopoietin (TSLP) was aberrantly expressed, which remained elevated after intravenous immunoglobulin G (IVIG) treatment and during convalescence in KD patients in comparison to healthy controls. Enzyme-linked immunosorbent assay (ELISA) corroborated the upregulation of TSLP in KD patients, which was exacerbated in convalescent patients complicated with thrombosis. TSLP receptors on platelets were also significantly upregulated in KD patients complicated with thrombosis. Platelet activation, apoptosis, and mitochondrial autophagy (mitophagy) were increased in convalescence KD patients complicated with thrombosis. In vitro, TSLP induced platelet activation and platelet mitophagy in healthy blood donors, as observed in KD patients. TSLP, similar to mitophagy agonist carbonyl cyanide 3-chlorophenyl hydrazone (CCCP), promoted thrombosis, which was attenuated by the mitophagy inhibitor Mdivi-1. Co-immunoprecipitation in TSLP-treated platelets revealed TSLP receptor (TSLPR) bound to mitophagy regulators, Parkin and Voltage Dependent Anion Channel Protein 1 (VDAC1).Thus, our results demonstrated that TSLP induced platelet mitophagy via a novel TSLPR/Parkin/VDAC1 pathway that promoted thrombosis in KD. These results suggest TSLP as a novel therapeutic target against KD-associated thrombosis.

Multisystem Inflammatory Syndrome in Children in New York State.

BACKGROUND: A multisystem inflammatory syndrome in children (MIS-C) is associated with coronavirus disease 2019. The New York State Department of Health (NYSDOH) established active, statewide surveillance to describe hospitalized patients with the syndrome. METHODS: Hospitals in New York State reported cases of Kawasaki's disease, toxic shock syndrome, myocarditis, and potential MIS-C in hospitalized patients younger than 21 years of age and sent medical records to the NYSDOH. We carried out descriptive analyses that summarized the clinical presentation, complications, and outcomes of patients who met the NYSDOH case definition for MIS-C between March 1 and May 10, 2020. RESULTS: As of May 10, 2020, a total of 191 potential cases were reported to the NYSDOH. Of 95 patients with confirmed MIS-C (laboratory-confirmed acute or recent severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2] infection) and 4 with suspected MIS-C (met clinical and epidemiologic criteria), 53 (54%) were male; 31 of 78 (40%) were black, and 31 of 85 (36%) were Hispanic. A total of 31 patients (31%) were 0 to 5 years of age, 42 (42%) were 6 to 12 years of age, and 26 (26%) were 13 to 20 years of age. All presented with subjective fever or chills; 97% had tachycardia, 80% had gastrointestinal symptoms, 60% had rash, 56% had conjunctival injection, and 27% had mucosal changes. Elevated levels of C-reactive protein, d-dimer, and troponin were found in 100%, 91%, and 71% of the patients, respectively; 62% received vasopressor support, 53% had evidence of myocarditis, 80% were admitted to an intensive care unit, and 2 died. The median length of hospital stay was 6 days. CONCLUSIONS: The emergence of multisystem inflammatory syndrome in children in New York State coincided with widespread SARS-CoV-2 transmission; this hyperinflammatory syndrome with dermatologic, mucocutaneous, and gastrointestinal manifestations was associated with cardiac dysfunction.

Multisystem Inflammatory Syndrome in U.S. Children and Adolescents.

BACKGROUND: Understanding the epidemiology and clinical course of multisystem inflammatory syndrome in children (MIS-C) and its temporal association with coronavirus disease 2019 (Covid-19) is important, given the clinical and public health implications of the syndrome. METHODS: We conducted targeted surveillance for MIS-C from March 15 to May 20, 2020, in pediatric health centers across the United States. The case definition included six criteria: serious illness leading to hospitalization, an age of less than 21 years, fever that lasted for at least 24 hours, laboratory evidence of inflammation, multisystem organ involvement, and evidence of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) based on reverse-transcriptase polymerase chain reaction (RT-PCR), antibody testing, or exposure to persons with Covid-19 in the past month. Clinicians abstracted the data onto standardized forms. RESULTS: We report on 186 patients with MIS-C in 26 states. The median age was 8.3 years, 115 patients (62%) were male, 135 (73%) had previously been healthy, 131 (70%) were positive for SARS-CoV-2 by RT-PCR or antibody testing, and 164 (88%) were hospitalized after April 16, 2020. Organ-system involvement included the gastrointestinal system in 171 patients (92%), cardiovascular in 149 (80%), hematologic in 142 (76%), mucocutaneous in 137 (74%), and respiratory in 131 (70%). The median duration of hospitalization was 7 days (interquartile range, 4 to 10); 148 patients (80%) received intensive care, 37 (20%) received mechanical ventilation, 90 (48%) received vasoactive support, and 4 (2%) died. Coronary-artery aneurysms (z scores ≥2.5) were documented in 15 patients (8%), and Kawasaki's disease-like features were documented in 74 (40%). Most patients (171 [92%]) had elevations in at least four biomarkers indicating inflammation. The use of immunomodulating therapies was common: intravenous immune globulin was used in 144 (77%), glucocorticoids in 91 (49%), and interleukin-6 or 1RA inhibitors in 38 (20%). CONCLUSIONS: Multisystem inflammatory syndrome in children associated with SARS-CoV-2 led to serious and life-threatening illness in previously healthy children and adolescents. (Funded by the Centers for Disease Control and Prevention.).

Differences in the Clinical Characteristics of Kawasaki Disease Between Older and Younger Children (2015-2019): A Single-Center, Retrospective Study.

OBJECTIVE: The objective of this study was to investigate the differences in the clinical characteristics of Kawasaki disease between older and younger children. STUDY DESIGN: This retrospective study examined 405 children with Kawasaki disease admitted to Showa University Northern Yokohama Hospital between 2015 and 2019. RESULTS: Eligible patients were classified into the older (≥3.0 years of age, n = 169) and younger (<3.0 years of age, n = 236) groups. Skin rash was found in significantly fewer cases (112 [66.3%] vs 229 [97.0%], P < .001 in the younger group). Cervical lymphadenopathy was more common in older children (153 [90.5%] vs 165 [69.9%], P < .001) and in incomplete Kawasaki disease (3 or 4 findings) (34 [20.1%] vs 25 [10.6%], P = .0078). The diagnosis was more delayed in older children (median: 5.0 days vs 4.0 days, P = .003) than the younger group. Additionally, fever nonresponsive to a single intravenous immunoglobulin was more common, and the duration of fever was significantly longer in the older group (48 [28.4%] vs 47 [19.9%], P = .0479). CONCLUSIONS: Kawasaki disease should be suspected in children aged >3.0 years with cervical lymphadenopathy and fever, despite the absence of skin rash. Additionally, incomplete Kawasaki disease, fever unresolved by a single intravenous immunoglobulin infusion, and the tendency to delay treatment initiation are more common in children aged >3.0 years.

Multisystemic Inflammatory Syndrome in Children and Kawasaki Disease: Parallels in Pathogenesis and Treatment.

PURPOSE OF REVIEW: Since it first appeared, multisystem inflammatory syndrome in children (MIS-C) associated with coronavirus disease 2019 (COVID-19) has been compared to Kawasaki disease (KD). Although there were early parallels between MIS-C and KD, key differences emerged over time. Here, we aim to compare the pathogenesis, clinical presentation, treatment, and outcomes of MIS-C and KD. RECENT FINDINGS: In this article, we review and compare MIS-C and KD, highlighting differentiating features. We discuss the epidemiological and immunological factors along with clinical and laboratory features which discern MIS-C from KD. We also compare treatment and our understanding of long-term outcomes. Though parallels exist between MIS-C and KD, distinguishing the two is important for clinical management of patients, counseling about natural history, and determining long-term monitoring. While both MIS-C and KD are characterized by profound inflammation and inflammatory vasculopathy, further study is needed to determine whether they are distinct immunopathogenic disorders.

Access to Care and Therapy for Kawasaki Disease in the Arab Countries: A Kawasaki Disease Arab Initiative (Kawarabi) Multicenter Survey.

Kawasaki Disease (KD) is still the most common acquired heart disease in children below the age of five years; it has been well described in the developed world; however, data from the Arab world are limited to case reports or single-center case series. In an effort of optimizing KD research in the Arab world, a group of physicians and researchers established the KD Arab Initiative (Kawarabi) in 2021, and published the first survey, which showed disparities in the availability of intravenous immunoglobulin (IVIG); this had prompted Kawarabi to assess the access to care and therapy of KD patients in Arab countries. A 32 structured questions survey was conducted in thirteen Arab countries and addressed KD patients' access to healthcare in urban and rural settings. The survey results showed that access to care was uniform across large, mid-size cities and rural areas in 7/13 (54%) countries, while in 6/13 (46%) countries, it was in favor of large and mid-size cities over rural areas. The quality of medical services received by children with KD in large cities was rated as excellent in 6/13 or good in 7/13 countries compared to fair in 4/13 or poor in 4/13 countries in rural areas. Availability of IVIG was limited (23%) in mid-size cities and almost impossible (23%) in rural areas. The KD patients in mid-size cities and rural areas have limited access to standard healthcare in the Arab world. This survey laid the foundation for future Kawarabi endeavors to improve the care of children with KD.

Diagnosis, Progress, and Treatment Update of Kawasaki Disease.

Kawasaki disease (KD) is an acute inflammatory disorder that primarily affects children and can lead to coronary artery lesions (CAL) if not diagnosed and treated promptly. The original clinical criteria for diagnosing KD were reported by Dr. Tomisaku Kawasaki in 1967 and have been used for decades. However, research since then has highlighted the limitations of relying solely on these criteria, as they might lead to underdiagnosis or delayed diagnosis, potentially increasing the risk of coronary artery complications. This review appears to discuss several important aspects related to KD diagnosis and management. The current diagnostic methods for KD might need updates, especially considering cases that do not fit the typical clinical criteria. Recognizing diagnostic pitfalls and distinguishing KD from other conditions that might have similar clinical presentations is essential. The differences and similarities between KD and Multisystem Inflammatory Syndrome in Children (MIS-C), another inflammatory condition that has been associated with COVID-19, were also reviewed. The review explores the potential role of eosinophil count, new biomarkers, microRNA panels, and scoring systems in aiding the diagnosis of KD. Overall, the review article provides a comprehensive overview of the evolving landscape of KD diagnosis and management, incorporating new diagnostic methods, biomarkers, and treatment approaches to improve patient outcomes and reduce the risk of complications.

[Diagnosis and treatment of incomplete Kawasaki disease in children]. / å„¿ç«¥ä¸å®Œå ¨æ€§å·å´Žç— çš„è¯Šæ²».

Kawasaki disease (KD) is a febrile disease mainly observed in children aged <5 years, with medium- and small-vessel vasculitis as the main lesion. Although KD has been reported for more than 50 years and great progress has been made in the etiology and pathology of KD in recent years, there is still a lack of specific indicators for the early diagnosis of KD, especially with more difficulties in the diagnosis of incomplete Kawasaki disease (IKD). At present, there are no clear diagnostic criteria for IKD, which leads to the failure of the timely identification and standardized treatment of IKD in clinical practice and even induce the development of coronary artery lesion. This article reviews the concept, epidemiological features, diagnosis, treatment, and follow-up management of IKD, in order to deepen the understanding of IKD among clinical workers and help to improve the clinical diagnosis and treatment of KD in China.

[Clinical application of plasma exchange combined with continuous veno-venous hemofiltration dialysis in children with refractory Kawasaki disease shock syndrome]. / 血浆置换联合连续性静脉-é™è„‰è¡€æ¶²æ»¤è¿‡é€æžæ²»ç–—åœ¨å„¿ç«¥å·å´Žç— ä¼‘å ‹ç»¼åˆå¾ä¸­çš„ä¸´åºŠåº”ç”¨.

OBJECTIVES: To study the role of plasma exchange combined with continuous blood purification in the treatment of refractory Kawasaki disease shock syndrome (KDSS). METHODS: A total of 35 children with KDSS who were hospitalized in the Department of Pediatric Intensive Care Unit, Hunan Children's Hospital, from January 2019 to August 2022 were included as subjects. According to whether plasma exchange combined with continuous veno-venous hemofiltration dialysis was performed, they were divided into a purification group with 12 patients and a conventional group with 23 patients. The two groups were compared in terms of clinical data, laboratory markers, and prognosis. RESULTS: Compared with the conventional group, the purification group had significantly shorter time to recovery from shock and length of hospital stay in the pediatric intensive care unit, as well as a significantly lower number of organs involved during the course of the disease (P<0.05). After treatment, the purification group had significant reductions in the levels of interleukin-6, tumor necrosis factor-α, heparin-binding protein, and brain natriuretic peptide (P<0.05), while the conventional group had significant increases in these indices after treatment (P<0.05). After treatment, the children in the purification group tended to have reductions in stroke volume variation, thoracic fluid content, and systemic vascular resistance and an increase in cardiac output over the time of treatment. CONCLUSIONS: Plasma exchange combined with continuous veno-venous hemofiltration dialysis for the treatment of KDSS can alleviate inflammation, maintain fluid balance inside and outside blood vessels, and shorten the course of disease, the duration of shock and the length of hospital stay in the pediatric intensive care unit.

[Evidence-based guidelines for the diagnosis and treatment of Kawasaki disease in children in China (2023)]. / ä¸­å›½å„¿ç«¥å·å´Žç— è¯Šç–—å¾ªè¯æŒ‡å—ï¼ˆ2023年）.

Kawasaki disease (KD) is an acute self-limiting vasculitis, and it is the most common cause of acquired heart disease in children under 5 years old. One of the improvement goals in pediatric quality control work for the year 2023, as announced by the National Health Commission, is to reduce the incidence of cardiac events and KD-related mortality in children with KD. In order to standardize the diagnosis, treatment, and long-term management practices of KD in China, and effectively prevent and reduce the incidence of coronary artery lesions and long-term adverse effects, the guideline working group followed the principles and methods outlined by the World Health Organization and referenced existing evidence and experiences to develop the "Evidence-based guidelines for the diagnosis and treatment of Kawasaki disease in children in China (2023)". The guidelines address the clinical questions regarding the classification and definition of KD, diagnosis of different types of KD, treatment during the acute phase of KD, application of echocardiography in identifying complications of KD, and management of KD combined with macrophage activation syndrome. Based on the best evidence and expert consensus, 20 recommendations were formulated, aiming to provide guidance and decision-making basis for healthcare professionals in the diagnosis and treatment of KD in children.

Medium- and Large-Vessel Vasculitis.

Systemic vasculitides are multisystem blood vessel disorders, which are defined by the size of the vessel predominantly affected, namely small, medium, or large vessels. The term "large vessel" relates to the aorta and its major branches; "medium vessel" refers to the main visceral arteries and veins and their initial branches. The most common causes of large-vessel vasculitis are giant cell arteritis and Takayasu arteritis, and those of medium-vessel arteritis are polyarteritis nodosa and Kawasaki disease. However, there is some overlap, and arteries of any size can potentially be involved in any of the 3 main categories of dominant vessel involvement. In addition to multisystem vasculitides, other forms of vasculitis have been defined, including single-organ vasculitis (eg, isolated aortitis). Prompt identification of vasculitides is important because they are associated with an increased risk of mortality. Left undiagnosed or mismanaged, these conditions may result in serious adverse outcomes that might otherwise have been avoided or minimized. The ethnic and regional differences in the incidence, prevalence, and clinical characteristics of patients with vasculitis should be recognized. Because the clinical presentation of vasculitis is highly variable, the cardiovascular clinician must have a high index of suspicion to establish a reliable and prompt diagnosis. This article reviews the pathophysiology, epidemiology, diagnostic strategies, and management of vasculitis.

Heart Transplant, Kawasaki Disease, and Bone Marrow Transplant: Are There Consequences?

PURPOSE OF REVIEW: This article reviews the current landscape of cardiovascular disease (CVD) risk factors, focusing on dyslipidemia, which contribute to atherosclerosis in three unique populations: youth less than 18 years-of-age with a history of Kawasaki disease, and those who have undergone orthotopic heart and bone marrow transplants. RECENT FINDINGS: Atherosclerosis, the major cause of CVD, begins in childhood. Acquired and genetic disorders of lipid and lipoprotein metabolism, present at an early age, are major contributors to early precursors of atherosclerosis, which accelerate after age 20. Treatment of the underlying medical condition and optimum management of all risk factors is critical in improving outcomes. Nonetheless, limited data is available to assist clinical decision-making, with the aim of improving outcomes. Atherosclerosis, beginning in childhood, is multifactorial in origin with complex interplay of inflammation, infection, endothelial dysfunction, and dyslipidemia. Future studies are needed to help elucidate the specific roles of disease mechanisms, with an emphasis on early intervention and prediction of subclinical disease. In addition to a heart healthy lifestyle, there may be a role for use of lipid-lowering medications beginning at an early age.

Acute myocardial infarction caused by Kawasaki disease requires more intensive therapy: Insights from the Japanese registry of All Cardiac and Vascular Diseases-Diagnosis Procedure combination.

BACKGROUND: Kawasaki disease (KD) induces coronary arteritis, which causes subsequent coronary aneurysms, and contributes to acute myocardial infarction (AMI). However, the differences regarding real-world treatment selection and mortality between AMI-complicated KD and AMI due to typical atherosclerosis (AMI-non KD) are unknown. AIM: The aim of the present study was to examine the current treatment strategy and prognosis of AMI-complicated KD compared with AMI due to typical atherosclerosis. METHOD: We used data from 2012 to 2019 from a nationwide claim database, the Japanese Registry of All Cardiac and Vascular Diseases-Diagnosis Procedure Combination. RESULTS: Compared to the AMI-non KD patients (n = 70,227), the AMI-complicated KD patients (n = 73): (1) underwent percutaneous coronary intervention (PCI) less often and more coronary artery bypass grafting, intracoronary thrombolysis or intravenous coronary thrombolysis more often; (2) underwent stentless PCI using old balloon angioplasty or rotablator, when they underwent PCI; and (3) needed in-hospital cardiopulmonary resuscitation and intensive mechanical therapy such as intra-aortic balloon pump, percutaneous cardiopulmonary support or a respirator. Both the AMI-non KD and AMI-complicated KD patients had similar in-hospital mortality rates. CONCLUSIONS: Compared with AMI-non KD patients, AMI-complicated KD patients underwent non-PCI strategies such as bypass surgery or thrombolysis, and required intensive therapy with mechanical supports more often, but presented similar in-hospital mortality. When the AMI-complicated KD patients underwent PCI, stentless PCI using balloon angioplasty or rotablator was performed more often compared with the AMI-non KD patients.

Human umbilical cord mesenchymal stem cells regulate CD54 and CD105 in vascular endothelial cells and suppress inflammation in Kawasaki disease.

OBJECTIVE: The objective was to evaluate the expression levels of CD31+CD54+ and CD31+CD105+ endothelial microparticles (EMPs) before and after intravenous immunoglobulin (IVIG) treatment of Kawasaki disease (KD). To explore the role of human umbilical cord mesenchymal stem cells (hucMSCs) in inhibiting endothelial inflammation in KD, the effects of hucMSCs on the expression of CD54 and CD105 in endothelial cells in KD were analyzed in vivo and in vitro. METHODS: The concentrations of IL-1ß and VEGF in the peripheral blood of KD or healthy children were detected, and the distributions of CD31+CD54+ and CD31+CD105+ EMPs in platelet-poor plasma (PPP) were analyzed by flow cytometry. Human umbilical vein endothelial cells (HUVECs) were first cocultured with the patients' peripheral blood mononuclear cells (PBMCs). Next, HUVECs were cocultured with hucMSCs after stimulation with inactivated serum from patients. Cell proliferation and migration activities were assessed, and the expression of CD54, CD105 and IL-1ß was analyzed. In an in vivo study, hucMSCs were transplanted into KD mice. The locations and expression levels of CD54, CD105 and IL-1ß in the heart tissues of mice were analyzed. RESULTS: The levels of IL-1ß and CD31+CD54+ EMPs were significantly higher before IVIG treatment and 2 weeks after treatment in KD patients (P < 0.01). However, the levels of VEGF and CD31+CD105+ EMPs increased significantly in KD only after IVIG treatment (P < 0.01). KD-inactivated serum stimulation combined with cocultivation of PBMCs can activate inflammation in HUVECs, leading to reduced cell proliferation and migration activities. Cocultivation also increased the expression of CD54 and decreased the expression of CD105 (P < 0.001). Cocultivation with hucMSCs can reverse these changes. Additionally, hucMSC transplantation downregulated the expression of IL-1ß and CD54 and significantly upregulated the expression of CD105 in KD mice. CONCLUSION: The expression levels of CD31+CD54+ and CD31+CD105+ EMPs showed inconsistent changes at different KD statuses, providing potential markers for clinical application. HucMSCs suppress inflammation and regulate the expression levels of CD54 and CD105 in vascular endothelial cells in KD, possibly providing a new basis for stem cell therapy for KD.

Acute phase of Kawasaki disease: a review of national guideline recommendations.

Key aspects of the medical management of Kawasaki disease (KD) are not yet supported by a high evidence level, thus making room for individual recommendations. We performed a structured comparison of existing international KD guidelines to analyze potential differences in the implementation of evidence-based KD recommendations regarding diagnosis and therapy. To identify country-specific guidelines, we took a multilateral approach including a comprehensive PubMed literature, online research, and directly contacting national pediatric associations. We then ran a structured guidelines' analysis and evaluated the diagnostic and therapeutic differences in the context of evidence-based medicine. In this structured guideline analysis, we identified nine national and one European guidelines. According to them all, the diagnosis of KD still relies on its clinical presentation with no reliable biomarker recommended. First-line treatment consistently involves only intravenous immunoglobulin (IVIG) therapy. Recommendations in terms of acetylsalicylic acid, corticosteroids, and additional therapeutic options vary considerably. CONCLUSION: According to all guidelines, KD is diagnosed clinically with some variance in defining incomplete KD and being a non-responder to treatment. First-line treatment consistently includes IVIG. Recommendations for additional therapeutic strategies are more heterogeneous. WHAT IS KNOWN: • The diagnosis of KD relies on the clinical presentation, entailing challenges in timely diagnosis. • Other treatment options then IVIG are not supported by a high evidence level, making room for individual recommendations. WHAT IS NEW: • Definition of incomplete KD and being non-responsive to an initial treatment vary to some extent between the national guidelines. • Only IVIG is consistently proposed throughout all guidelines, further therapeutic recommendations vary between the national recommendations.

Kawasaki disease shock syndrome with acute respiratory distress syndrome in a child: a case report and literature review.

BACKGROUND: Kawasaki disease (KD) is an acute systemic vasculitis that may involve multiple organs. KD shock syndrome (KDSS) is a rare complication of KD. Pulmonary involvement is rare in KD; reports of patients with KD who develop KDSS and acute respiratory distress syndrome (ARDS) are extremely rare. CASE PRESENTATION: A 2-year-old girl was brought to the emergency department with fever, cough and tachypnea. The patient was diagnosed with KDSS and ARDS. Extracorporeal membrane oxygenation (ECMO) and continuous blood purification were performed because of her critical condition. The patient eventually recovered completely. One year after discharge, there has been no coronary artery dilatation or pulmonary fibrosis. CONCLUSION: KDSS patients may develop ARDS due to fluid resuscitation and the release of inflammatory mediators. Early aggressive management and comprehensive treatment may improve prognosis.

Myocardial infarction due to thrombotic occlusion despite anticoagulation in Kawasaki disease - a case report.

BACKGROUND: Kawasaki disease (KD) is a pediatric vasculitis. Mainly the coronary arteries become affected due to acute inflammation and formation of coronary artery aneurysms (CAAs) can occur. The larger the CAA, the higher the risk for clinical complications and major adverse cardiac events, as the blood flow changes to vortex or turbulent flow facilitating thrombosis. Such patients may develop life threatening thrombotic coronary artery occlusion and myocardial ischemiaunless anti-platelet and anti-coagulation therapy is timely initiated. CASE PRESENTATION: We present a unique case of a 5-year-old girl with KD associated giant CAAs suffering from myocardial ischemia due to acute progressive thrombus growth despite intensive anticoagulation treatment (acetylsalicylic acid, acenocoumarol and clopidogrel) after 21 months of onset of disease. Thrombus growth continued even after percutaneous coronary intervention (PCI) with thrombolytic treatment and subsequent systemic thrombolysis, finally causing lasting myocardial damage. Acute coronary artery bypass grafting (CABG) was performed, although technically challenging at this very young age. Whereas myocardial infarction was not prevented, follow-up fortunately showed favorable recovery of heart failure. CONCLUSIONS: Anticoagulation and thrombolysis may be insufficient for treatment of acute coronary syndrome in case of impending thrombotic occlusion of giant coronary aneurysms in KD. Our case demonstrates that a thrombus can still continue to grow despite triple anticoagulation therapy and well-tailored cardiovascular follow-up, which can be most likely attributed to the state of low blood flow inside the aneurysm.

Explanations for 10 of the most puzzling aspects of multisystem inflammatory syndrome and other Kawasaki-like diseases.

WHAT IS KNOWN AND OBJECTIVE: An extensively documented multisystem inflammatory syndrome (MIS) has been observed in a small but significant percentage of COVID-19 patients, in some adults but primarily in paediatric patients, and for these patients it is sometimes called MIS-C. COMMENT: Kawasaki disease has also been observed over the last several decades in patients that tested positive for a variety of very virulent pathogens. Several differences and similarities between MIS-C and Kawasaki disease pathology have been observed. Several puzzling aspects of MIS-C, Kawasaki disease and other Kawasaki-like diseases have been discussed, but not yet explained. WHAT IS NEW AND CONCLUSION: An explanatory hypothesis has been presented. Using the hypothesis that a transient or permanent inability to quickly phagocytize antigen-antibody immune complexes created by a novel virulent pathogen infection induces a Type III hypersensitivity immune response and the resulting proteinase exposure and expression of new autoantigens are the fundamental steps for MIS and other Kawasaki-like diseases, it is possible to provide straightforward explanations for at least 10 of the most puzzling aspects of these diseases. The validity of the hypothesis itself is also supported by its ability to provide consistent and straightforward explanations for a large number of these disease aspects. Furthermore, these straightforward explanations and the explanatory hypothesis on which they are based also suggest several potential new treatments, which could possibly be more effective than various treatments in current use.