Multisystem inflammatory syndrome in children (MIS-C) without antecedent clinical symptoms related to COVID-19: The increasing importance of distinguishing MIS-C in patients with Kawasaki disease-like features.

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in most children result in an asymptomatic or milder course of coronavirus disease 2019 (COVID-19) compared with infections in adults [1]. How-ever, SARS-CoV-2 infection in children may rarely result in hyperinflammatory features similar to Kawasaki disease (KD) and toxic shock syndrome, known as ‘multisystem inflammatory syndrome in children’ (MIS-C). We report a Japanese case of MIS-C without antecedent clinical symptoms related to COVID-19.A9-year-old Japanese boy presented to our hospital because he had a fever 3 days prior to his visit, after which he developed conjunctival hyperaemia, redness of the lips (Figure 1(a)), and diarrhoea. He was not vaccinated against SARS-CoV-2, and he had no apparent history of illness and no respiratory symptoms or fever suggestive of COVID-19 within the preceding few months. He had not knowingly had close contact