Creation of prediction tool to guide further workup of febrile children in the emergency department under consideration for Multisystem Inflammatory Syndrome in children

Multisystem Inflammatory Syndrome in Children (MIS-C) is a post-infectious complication of COVID-19 in children. Its workup often necessitates extensive laboratory investigations. This project sought to provide pediatric acute care providers with a data-based tool to guide further decision-making during initial workups for children under consideration for MIS-C. We compared documented physical findings and laboratory data (complete blood counts, inflammatory markers, and electrolytes) from MIS-C cases (n = 46) to control data extracted from a pre-pandemic database of febrile children (n = 70). Significant findings on Fisher's exact test and independent t-tests were used to develop a scoring model. Receiver operating characteristic (ROC) curve analysis was performed to assess this scoring system using two different cohorts of MIS-C. From initial comparative analysis, a score (≥3) utilizing levels of CRP, lymphocytes, platelets, and total white blood cells was developed. ROC curve analysis demonstrated excellent parameters, with overall sensitivity of 97.83 %. In children <9 years old, the score had a sensitivity of 96.15 % and in ≥9 years old, the score demonstrated a sensitivity of 100.00 %. We validated the score on a geographically disparate cohort by showing a sensitivity of 88.37 % of all children and 94.74 % in children ≥2 years of age. Use of this scoring system based on readily available laboratory values can eliminate many febrile children from consideration of MIS-C allowing front-line providers to focus more extensive laboratory evaluations and extended observation on fewer children with a higher likelihood of having MIS-C.