COVID-19 in children: Pathogenesis and current status.

Area of Science:

• Pediatric Infectious Diseases
• Immunology
• Virology

Background:

• Coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2, has become a global pandemic.
• Children with COVID-19 generally exhibit milder symptoms compared to adults, with fewer cases of severe respiratory illness.
• A subset of children can develop severe respiratory disease or a hyperinflammatory response, termed multisystem inflammatory syndrome in children (MIS-C), which shares similarities with Kawasaki disease (KD).

Purpose of the Study:

• To review current evidence on the pathogenesis of COVID-19 in children.
• To investigate the relationship between COVID-19, Kawasaki disease (KD), and multisystem inflammatory syndrome in children (MIS-C).
• To enhance understanding of the clinical course, diagnosis, and management of these conditions in pediatric populations.

Main Methods:

• Review of existing scientific literature and evidence.
• Analysis of the distinct phases of COVID-19 pathogenesis.
• Comparative examination of clinical features in children with KD versus MIS-C.

Main Results:

• COVID-19 pathogenesis involves two overlapping phases: viral infection and host immune response.
• Children with KD show fewer COVID-19-associated KD features, less severe acute respiratory distress syndrome, and shock compared to children with MIS-C.
• Children's immature immune systems contribute to milder COVID-19 disease presentation.

Conclusions:

• While most children experience mild COVID-19, some develop SARS-CoV-2-associated MIS-C, presenting a hyperinflammatory state.
• MIS-C in children shares clinical similarities with Kawasaki disease.
• Understanding the distinct pathogenesis and clinical presentations is crucial for managing pediatric COVID-19 and related inflammatory syndromes.