OBJECTIVE: Although the initial reports of COVID-19 cases in children described 
that children were largely protected from severe manifestations, clusters of 
paediatric cases of severe systemic hyperinflammation and shock related to 
severe acute respiratory syndrome coronavirus 2 infection began to be reported 
in the latter half of April 2020. A novel syndrome called "multisystem 
inflammatory syndrome in children" (MIS-C) shares common clinical features with 
other well-defined syndromes, including Kawasaki disease, toxic shock syndrome 
and secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome. 
Our objective was to develop a protocol for the evaluation, treatment and 
follow-up of patients with MIS-C.
METHODS: The protocol was developed by a multidisciplinary team. We convened a 
multidisciplinary working group with representation from the departments of 
paediatric critical care, cardiology, rheumatology, surgery, gastroenterology, 
haematology, immunology, infectious disease and neurology. Our protocol and 
recommendations were based on the literature and our experiences with 
multisystem inflammatory syndrome in children. After an agreement was reached 
and the protocol was implemented, revisions were made on the basis of expert 
feedback.
CONCLUSION: Children may experience acute cardiac decompensation or other organ 
system failure due to this severe inflammatory condition. Therefore, patients 
with severe symptoms of MIS-C should be managed in a paediatric intensive care 
setting, as rapid clinical deterioration may occur. Therapeutic approaches for 
MIS-C should be tailored depending on the patients' phenotypes. Plasmapheresis 
may be useful as a standard treatment to control hypercytokinemia in cases of 
MIS-C with severe symptoms. Long-term follow-up of patients with cardiac 
involvement is required to identify any sequelae of MIS-C.