Characterizing the differences between multisystem inflammatory syndrome in children and Kawasaki disease.

To characterize the new SARS-Co-V-2 related multisystem inflammatory syndrome in children (MIS-C) among Israeli children and to compare it with Kawasaki disease (KD). We compared, in two medical centers, the clinical and laboratory characteristics of MIS-C, KD and an intermediate group, which met the case definitions of both conditions. MIS-C patients were older, were more likely to be hypotensive, to have significant gastrointestinal symptoms, lymphopenia and thrombocytopenia and to have non-coronary abnormal findings in their echocardiogram. Lymphopenia was an independent predictor of MIS-C. Most of our MIS-C patients responded promptly to corticosteroid therapy. KD incidence in both centers was similar in 2019 and 2020. Although there is clinical overlap between KD and MIS-C, these are separate entities. Lymphopenia clearly differentiates between these entities. MIS-C patients may benefit from corticosteroids as first-line therapy.