Presentation, Treatment Response and Short-Term Outcomes in Paediatric Multisystem Inflammatory Syndrome Temporally Associated with SARS-CoV-2 (PIMS-TS).

The novel Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is the pathogen responsible for Coronavirus Disease 2019 (COVID-19). Whilst most children and young people develop mild symptoms, recent reports suggest a novel paediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 (PIMS-TS). Case definition and classification are preliminary, treatment is empiric and disease-associated outcomes are unclear. Here, we report 29 patients with PIMS-TS who were diagnosed, admitted and treated in the English North West between March and June 2020. Consistent with patterns observed internationally, cases peaked approximately 4 weeks after the initial surge of COVID-19-like symptoms in the UK population. Clinical symptoms included fever (100%), skin rashes (72%), cardiovascular involvement (86%), conjunctivitis (62%) and respiratory involvement (21%). Some patients had clinical features partially resembling Kawasaki disease (KD), toxic shock syndrome and cytokine storm syndrome. Male gender (69%), black, Asian and other minority ethnicities (BAME, 59%) were over-represented. Immune modulating treatment was used in all, including intravenous immunoglobulin (IVIG), corticosteroids and cytokine blockers. Notably, 32% of patients treated with IVIG alone went into remission. The rest required additional treatment, usually corticosteroids, with the exception of two patients who were treated with TNF inhibition and IL-1 blockade, respectively. Another patient received IL-1 inhibition as primary therapy, with associated rapid and sustained remission. Randomized and prospective studies are needed to investigate efficacy and safety of treatment, especially as resources of IVIG may be depleted secondary to high demand during future waves of COVID-19.