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

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. 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. 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). 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.