Pathophysiology and Clinical Presentation of COVID-19 in Children: Systematic Review of the Literature

Introduction: Coronavirus disease 2019 (COVID-19) is due to severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) infection, which belongs to beta-coronaviruses of the Coronaviridae family. SARS-coV-2 causes acute respiratory infection with varying severity in different age groups, wherein adults can develop severe disease, while children are relatively spared until now, with COVID-19 in children accounting for only 1-5% of diagnosed cases. Although COVID-19 incidence rate in children is relatively low, their protection from COVID-19 is still a matter of increasing concern as children constitute a large vulnerable population. In order to develop effective therapeutic management and preventive measures against COVID-19 in children, there is an urgent need for a better understanding of its pathophysiology at the molecular level and clinical presentation as well as possible protective mechanisms in the pediatric population. Objectives: There is limited data regarding the incidence and clinical presentation of SARS-CoV-2 infection in children. Our goal was to understand the clinical picture and presentation of pediatric patients with confirmed COVID-19. Methods: A systematic literature search of popular medical databases (PubMed, Cochrane Central Register of Clinical Trials and Scopus), restricted to English language publications only, was conducted by us. We chose published peer-reviewed and cross-sectional articles as well as case series providing clinical signs, imaging findings and laboratory results of pediatric patients, using the following inclusion criteria: children aged up to 18 years who tested positive for COVID-19 and in whom SARS-Co-V-2 was detected in the nasal/throat swab by real time polymerase chain reaction (RT-PCR). Conclusion: Our review revealed that, in children, COVID-19 was milder in terms of disease severity and clinical presentation, and it had a better prognosis and a lower mortality rate than adults.