Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection may result in the multisystem inflammatory syndrome in children (MIS-C). The clinical presentation of MIS-C includes fever, severe illness, and the involvement of two or more organ systems, in combination with laboratory evidence of inflammation and laboratory or epidemiologic evidence of SARS-CoV-2 infection. Some features of MIS-C resemble Kawasaki Disease, toxic shock syndrome, and secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome. The relationship of MIS-C to SARS-CoV-2 infection suggests that the pathogenesis involves post-infectious immune dysregulation. Patients with MIS-C should ideally be managed in a pediatric intensive care environment since rapid clinical deterioration may occur. Specific immunomodulatory therapy depends on the clinical presentation. The relationship between the immune response to SARS-CoV-2 vaccines in development and MIS-C requires further study.

The SARS-CoV-2 pandemic has impacted millions of lives worldwide. Molecular assays and serological tests have been approved under EUA (emergency use authorization) by the FDA (food and drug administration), given these unprecedented times. These tests are not only critical for confirming the clinical diagnosis and making therapeutic decisions but also play an important role in the understanding of the epidemiology of the pandemic. There is limited experience with currently available tests and differences may exist among tests even using similar technology. The focus of this review is to improve clinicians’ understanding of SARS-CoV-2 test procedures including their limitations. We discuss the impact of different host and environmental factors on test results.