Clinical Characteristics, Treatment, and Outcomes of Multisystem Inflammatory Syndrome in Children Associated with COVID-19: A Single-Center Study from Iran

Background: Multisystem inflammatory syndrome in children (MIS-C) is a rare but serious post-infectious inflammatory condition associated with SARS-CoV-2 infection in children. While the pathogenesis remains unclear, it is considered an immune-mediated hyper inflammatory reaction triggered by the virus. Objectives: To investigate the clinical characteristics, laboratory findings, treatments, and outcomes of MIS-C cases in an Iranian hospital. Methods: A retrospective review was conducted of 102 children meeting the World Health Organization (WHO) diagnostic criteria for MIS-C admitted to Firoozabadi Hospital in Tehran from March 2020 to February 2021. Demographic, clinical, laboratory, and outcome data were extracted from medical records. Results: Fever (96.1%) and cough (47.1%) were the most common presenting symptoms, followed by ill appearance (47.1%), nausea/vomiting (36.3%), and dyspnea (35.3%). Neurological involvement included seizures in 28.4% of cases. Lymphopenia was observed in 55.5% of patients, and abnormal blood gas levels, including hypocapnia or hypercapnia, were present in 90.6% of cases. Common treatments included antibiotics (78.0%), corticosteroids (44.0%), remdesivir (25.0%), and IVIG (13.0%). The recovery rate was 90.2%, with 26.5% of patients requiring PICU admission, and a mortality rate of 9.8%. Conclusions: This study provides epidemiological data on MIS-C in Iran, demonstrating both similarities and differences compared to previous literature. The high rate of respiratory and neurological involvement, along with distinct treatment patterns, highlights the need for further research to optimize management strategies across different healthcare settings.