Background: Febrile seizure is the most common childhood neurological disorder, is an important health problem with potential short-and long-term complications, also leading to economic burden and increased parental anxiety about fevers and seizures occurring in their children. There are no routine recommendation to detect etiological causes of FS for neurological perspective, further knowledge about the etiological causes of FS in children will support preventive measures and follow-up strategies. The aim of this study is to evaluate the percentage of respiratory viruses in children with FS. Methods: This prospective multicenter study, entitled "Viral etiological causes of febrile seizures for respiratory pathogens (EFES Study)" examined representative populations in eight different cities in Turkey between March 1, 2016 and April 1, 2017. Nasopharyngeal swabs were taken from all children at presentation. A respiratory multiplex array was performed to detect for influenza A and B; respiratory syncytial virus A and B; human parainfluenza virus 1-2-3 and 4; human coronavirus 229E and OC43; human rhinovirus; human enterovirus; human adenovirus; human bocavirus; human metapneumovirus. Results: During the study period, at least one virus was detected in 82.7% (144/174) of children with FS. The most frequently detected virus was adenovirus, followed by influenza A and influenza B. Detection of more than one virus was present in 58.3% of the children with FS, and the most common co-existence was the presence of adenovirus and influenza B. In children younger than 12 months, Coronavirus OC43 was the most common, while influenza A was most frequently observed in children older than 48 months (p < 0.05). Human bocavirus was common in children who experienced complex FS, while respiratory syncytial virus (RSV) A was more common in children who experienced simple FS. Influenza B virus was the most common virus identified in children who were experiencing their first incidence of FS (p < 0.05).Conclusions: This study indicates that respiratory viruses are important in the etiology of FS in children. The results show that antibiotics must be prescribed carefully in children with FS since the majority of cases are related to viral causes. Widespread use of the existing quadrivalent influenza vaccine might be useful for the prevention of FS related to the flu. Further vaccine candidates for potential respiratory pathogens, including RSV, might be helpful for the prevention of FS. ARTICLE HISTORY

Aims: Limited data about disease management strategies are available for pediatric patients with coronavirus disease-2019, particularly in Turkey. This study aimed to share the data on patients aged under 18 years in our country to be beneficial for understanding the disease course in children. Methods: A retrospective review of the medical records of pediatric patients aged under 18 years who were confirmed as coronavirus disease-2019 between March 11, and June 23, 2020, and were admitted to our hospitals was conducted. Results: A total of 220 pediatric patients with coronavirus disease-2019 were evaluated, of which 48.2% were boys, with a median age of 10 years, and 9.5% had underlying diseases. Patients were classified according to severity, with the percentages of asymptomatic, mild, moderate, and critical/severe cases determined to be 25.5%, 45%, 26.8%, and 2.7%, respectively. Extracorporeal membrane oxygenation was required in two patients (0.9%) and mechanical ventilation in three (1.4%). Targeted therapies were used in six patients (2.7%), with hydroxychloroquine being the most commonly used agent either alone (one patient) or in combination with favipiravir (five patients). Two patients (0.9%) died, and nine (4.1%) were still hospitalized during the study period. Conclusion: Although the disease course of coronavirus disease-2019 seems to be mild in children, critical illness is significant, and the treatment strategy primarily should consist of supportive care according to our preliminary observations.

To compare the clinical and laboratory findings of multisystem inflammatory syndrome in children (MIS-C), patients with Kawasaki disease (KD) and with macrophage activating syndrome due to systemic juvenile idiopathic arthritis (sJIA-MAS) on real-life data. Patients diagnosed with MIS-C, KD, and sJIA-MAS from 12 different centers in Turkey who were followed for at least 6 months were included in the study. Demographic, clinical, and laboratory findings of all patients were analyzed. A total of 154 MIS-C, 59 KD, and 31 sJIA-MAS patients were included. The median age of patients with MIS-C were higher than those with KD while lower than those with sJIA-MAS (8.2, 3, 12 years, respectively). Myalgia (39.6%), cardiac (50.6%), gastrointestinal (72.7%), and neurological (22.1%) involvements were more common in patients with MIS-C compared to others. MIS-C patients had lower levels of lymphocyte (950 vs 1700 cells/µl) and thrombocyte (173,000 vs 355,000 cells/µl) counts and higher pro-BNP (1108 vs 55 pg/ml) levels than KD. Ferritin levels were higher in patients with MIS-C compared to patients with KD while they were lower than patients with sJIA-MAS (440, 170, 10,442 ng/ml, respectively). Patients with MIS-C had a shorter duration of hospitalization than sJIA-MAS ( p = 0.02) while they required intensive care unit admission more frequently (55 vs 8 patients, p < 0.001). The median MAS/sJIA score of MIS-C patients was − 1.64 (− 5.23 to 9.68) and the median MAS/sJIA score of sJIA-MAS patients was −2.81 ([− 3.79] to [− 1.27]). MIS-C patients displayed certain differences in clinical and laboratory features when compared to KD and sJIA-MAS. Definition of the differences and similarities between MIS-C and the other intense inflammatory syndromes of childhood such as KD and MAS will help the clinicians while making timely diagnosis.

Objective We aimed to describe the typical clinical and laboratory features and treatment of children diagnosed with multisystem inflammatory syndrome in children (MIS-C) and to understand the differences as compared to severe/critical pediatric cases with COVID-19 in an eastern Mediterranean country. Methods Children (aged <18 years) who diagnosed with MIS-C and severe/critical pediatric cases with COVID-19 and were admitted to hospital between March 26 and November 3, 2020 were enrolled in the study. Results A total of 52 patients, 22 patients diagnosed with COVID-19 with severe/critical disease course and 30 patients diagnosed with MIS-C, were included in the study. Although severe COVID-19 cases and cases with MIS-C share many clinical and laboratory features, MIS-C cases had longer fever duration and higher rate of the existence of rash, conjunctival injection, peripheral edema, abdominal pain, altered mental status, and myalgia than in severe cases (p<0.001 for each). Of all, 53.3% of MIS-C cases had the evidence of myocardial involvement as compared to severe cases (27.2%). Additionally, C-reactive protein (CRP) and white blood cell (WBC) are the independent predictors for the diagnosis of MIS-C, particularly in the existence of conjunctival injection and rash. Corticosteroids, intravenous immunoglobulin (IVIG), and biologic immunomodulatory treatments were mainly used in MIS-C cases rather than cases with severe disease course. There were only three deaths among 52 patients, one of whom had Burkitt lymphoma and the two cases with severe COVID-19 of late referral. Conclusion Differences between clinical presentations, acute phase responses, organ involvements, and management strategies indicate that MIS-C might be a distinct immunopathogenic disease as compared to pediatric COVID-19. Conjunctival injection and higher CRP and low WBC count are reliable diagnostic parameters for MIS-C cases. Keywords Kawasaki disease. Pediatrics. Hyperinflammation. Multisystem inflammatory syndrome in children (MIS-C). Multisystem inflammatory syndrome in adults (MIS-A) Key Points • MIS-C cases had longer fever duration and higher rate of the existence of rash, conjunctival injection, peripheral edema, abdominal pain, altered mental status, and myalgia than in severe/critical pediatric cases with COVID-19. • Higher CRP and low total WBC count are the independent predictors for the diagnosis of MIS-C. • MIS-C might be a distinct immunopathogenic disease as compared to pediatric COVID-19.

Background: A crucial balance exists between oxidant and antioxidant mechanisms in the functional immune system. We aimed to evaluate the contributions of balance between these systems to coronavirus disease 2019 (COVID-19), a devastating pandemic caused by viral infection.Method: We analyzed serum oxidant and antioxidant stress parameters according to the clinical and demographic characteristics of children and adults with COVID-19 and compared them against the values of healthy controls. Serum native thiol (NT), total thiol (TT), disulfide, total antioxidant status, total oxidant status, and ischemia-modified albumin levels were evaluated and compared between groups.Results: A total of 79 children and 74 adults were evaluated in the present study, including 46 children and 40 adults with COVID-19, 33 healthy children, and 34 healthy adults. TT, NT, and disulfide levels were significantly lower in the adult COVID-19 group than in all other groups (p = .001, p = .001, and p = .005, respectively). Additionally, TT and NT levels were significantly lower in both pediatric and adult COVID-19 cases with severe disease course than mild/moderate course. TT and NT levels were identified as predictors for the diagnosis of the adult COVID-19 cases and as independent predictors for disease severity in both children and adults with COVID-19. Conclusion:Parameters that reveal the oxidant and antioxidant capacity, including TT and NT, appear to be good candidates for the accurate prediction of the clinical course among patients with COVID-19.