Introduction
In April 2020, clinical reports documented the occurrence of a
multisystem inflammatory syndrome in children (MIS-C) during the
COVID-19 pandemic in the United States, United Kingdom, Italy, and
France. On May 14, 2020, the Centers for Disease Control and
Prevention’s Health Alert Network issued a global alert for MIS-C after
identifying a possible link between this critical illness in children
and infection from the novel coronavirus SARS-COV-2, the virus that
causes the COVID-19 disease[1]. The
main manifestations of MIS-C in the setting of a severe inflammatory
state include fever, diarrhea, shock, and variable presence of rash,
conjunctivitis, extremity edema, and mucous membrane changes, and in
some cases this can lead to the development of multi-organ
failure[2]. The multi-organ failure in
MIS-C is manifest by neurologic involvement, hyperferritinemia, and
cardiogenic or vasoplegic shock [3].
Children with severe MIS-C cases who have either previous exposure to
SARS-CoV-2 or tested positive for SARS-CoV-2 were admitted to the
intensive care units for shock or acute heart dysfunction
[4].
The MIS-C features share some aspects of the Kawasaki syndrome in terms
of multisystem inflammation and high levels of inflammatory biomarkers.
However, whereas MIS-C has been reported in individuals who are upto 21
years of age with a higher rate of cardiac involvement
[3], patients with Kawasaki syndrome
has been shown to occur predominantly in infants and children under 5
years old [4]. The etiology of
Kawasaki disease remains unknown, with evidence suggesting that
infectious agents could trigger the initiation of this disease. Multiple
cases of previously healthy children who developed MIS-C syndrome were
shown to be associated with a clinical or subclinical SARS-COV-2
infection. At present, it is unclear whether the SARS-COV-2 infection
could ignite the inflammation cascade that causes MIS-C illness.
Whereas it was previously thought that SARS-COV-2 infection shows mild
to asymptomatic disease in children and those that become infected are
not susceptible to pneumonia secondary to COVID-19 infection, this view
has significantly changed following the documentation of MIS-C in select
cases of pediatric SARS-CoV-2
infection[5]. These findings has led
to the conclusion that clearly more detailed studies are required to
more precisely define the molecular aspects of the triggering factors of
MIS-C during the COVID-19 pandemic.