Clinical presentation, diagnosis, management and outcomes of multisystem inflammatory syndrome in children (MIS-C)- a systematic review and meta-analysis

Knowledge about multisystem inflammatory syndrome in children (MIS-C) is still evolving, and evidence-based standardized diagnostic and management protocols are lacking. An analysis of the published evidence can help fill this gap. The aim is to evaluate the clinical and diagnostic features, management strategies, and outcomes of MIS-C and evaluate the variances between high-income countries and lower-middle-income countries (LMIC). Case series, cohorts, case-control, and cross-sectional studies that included the clinical presentation, diagnostic features, management, and outcomes of MIS-C patients with a sample size of ten or more patients were included. PubMed, Cumulative Index of Nursing and Allied Health Literature (CINAHL), Cochrane Library, and LitCovid were searched from December 2019 to March 2023. Forest plots were created for each variable using R. Mean and prevalence ratios were pooled using random effects model. A mixed generalized linear model was employed to account for the heterogeneity and publication bias was assessed via Egger test and Doi plots. The primary outcome was pooled mean and prevalence of MIS-C patient profile variables. Subgroup analysis was conducted based on the income class of the country. A total of 120 studies were included. Fever (99%; 95% CI, 99.6–100%), gastrointestinal symptoms (76.7%; 95% CI, 73.1–79.9%), and dermatological symptoms (63.3%; 95% CI, 58.7–67.7%) were frequently observed along with raised inflammatory, coagulation and cardiac markers. Intravenous immunoglobulins (87.5%; 95% CI, 82.9–91%) and steroids (74.7%; 95% CI, 68.7–79.9%) were the mainstays of management. Pediatric intensive care unit (PICU) admission (53.1%; 95% CI, 47.3–58.9%) was likely, but the overall mortality rate was low (3.9%; 95% CI, 2.7–5.6%). Patients in LMIC were younger and more likely to present with respiratory symptoms and develop coronary findings on echocardiogram, IVIG was less frequently used, with a longer hospital and PICU stay, and a higher mortality rate (10%). The wide gap in mortality rates between HIC and LMIC shown by our meta-analysis highlights the importance of focusing studies and policies on identifying and addressing this disparity. 1. WHO Coronavirus (COVID-19) Dashboard | WHO Coronavirus (COVID-19) Dashboard With Vaccination Data. Accessed May 19, 2023. https://covid19.who.int/ 2. Zimmermann P, Curtis N. Coronavirus Infections in Children Including COVID-19. Pediatr Infect Dis J. 2020;39(5):355–368. doi:https:/