Paediatric inflammatory multisystem syndrome temporally associated with COVID-19: a new virus and a new case presentation.

An 11-year-old boy presented with features resembling those described in health alerts on Paediatric Inflammatory Multisystem Syndrome Temporally associated with SARS-CoV-2 (PIMS-TS), including persistent fever, haemodynamic instability and abdominal pain. Laboratory tests, including raised inflammatory markers, D-dimer, troponin and a coagulopathy, were consistent with PIMS-TS. Our patient required transfer to the paediatric intensive care unit; an echocardiography revealed left ventricular dysfunction. He was treated with intravenous immunoglobulins (Igs), corticosteroids and aspirin, with full resolution of clinical symptoms. A follow-up echocardiogram 1 month after discharge was unremarkable. Three SARS-CoV-2 PCRs on respiratory samples, taken over the initial 4-day period, were negative, as was a SARS-CoV-2 PCR on faeces 1 month after presentation; titres of IgG were clearly elevated. The negative PCRs in the presence of elevated titres of IgG suggest that the inflammatory syndrome might have developed in a late phase of COVID-19 infection when the virus was no longer detectable in the upper airway.