Clinical features of post-COVID syndrome in pediatric patients: a literature review

In recent years, the global medical and scientific community has continued to investigate COVID-19. Scientific attention, however, has shifted beyond the emergence of novel variants to include the development of postCOVID syndrome, which may occur in both adults and children. Aim. To characterize the features of development and clinical manifestations of post-COVID-19 syndrome in children based on an analysis of the scientific literature. Materials and methods. A narrative review of studies published between 2020 and 2025 retrieved from PubMed, Scopus, Web of Science, Google Scholar, ScienceDirect, UpToDate, and selected Ukrainian peer-reviewed journals was conducted. Eligible studies addressed clinical features, laboratory biomarkers, echocardiography and cardiac MRI findings, multisystem inflammatory syndrome in children (MIS-C), and coagulopathy in pediatric patients. Results. The reported prevalence of pediatric post-COVID-19 syndrome ranges from 4 % to 66 %. Among affected children, 10–27 % exhibit persistent symptoms 2–5 months after acute recovery. Common manifestations include fatigue, dyspnea, headache, cognitive complaints, anxiety, tachycardia, and sleep disturbance. Cardiac alterations were reported in 25–75 % of cases across included studies; findings encompass transient myocardial dysfunction, reduced left-ventricular ejection fraction, left ventricular dilatation, and arrhythmias. In MIS-C patients, NT-proBNP and troponin I elevations and systolic impairment are more pronounced compared to non-MIS-C post-COVID-19 cases. Coagulopathy is characterized by increased D-dimer and fibrinogen levels with a relatively low rate of overt thrombosis. Correlations among D-dimer, NT-proBNP, and ferritin levels highlight endothelial dysfunction as a central pathophysiologic driver. Conclusions. Pediatric post-COVID-19 syndrome is a multisystem entity dominated by endothelial-inflammatory mechanisms. NT-proBNP, D-dimer, and troponin I, together with echocardiography and cardiac MRI, are essential for risk stratification and long-term follow-up. Standardized monitoring protocols and long-term outcome studies are urgently needed.