Multisystem inflammatory syndrome in children is a newly described condition temporarily associated with severe acute respiratory syndrome coronavirus 2. The primary observations indicated coronavirus disease 2019 infection in children to be mild. However, recent reports have revealed a correlation between multisystem inflammatory symptoms and coronavirus infection. The manifestation of the disease is similar to Kawasaki disease, toxic shock syndrome and macrophage activation syndrome. Treatment includes intravenous corticosteroids, immunoglobulin and biological therapy (anakinra, tocilizumab, infliximab). In this article we compare world reports of multisystem inflammatory syndrome in children to case reports of two patients who were hospitalized recently at the Department of Paediatric Cardiology and Rheumatology. In the course of diagnostics they presented numerous symptoms which required differentiation from multisystem inflammatory syndrome in children.