Since late April, more and more cases of multisystem inflammatory syndrome in children (MIS-C) have been found around the United States. A report from Italy provides more information on how it differs from Kawasaki disease.
In April, doctors started raising an alarm that they were seeing children who had a disease that mimicked elements of Kawasaki. A report in the Lancet compares multisystem inflammatory syndrome cases at a hospital in the Italian province of Bergamo with previously diagnosed Kawasaki disease shock syndrome in the same hospital.1
In the past 5 years, all 29 of the patients had been diagnosed with a Kawasaki-like disease at the hospital. They were divided into 2 groups: One group had patients who were diagnosed before the COVID-19 pandemic and the other had patients who were diagnosed after the pandemic started. The disease was managed as Kawasaki disease according to the American Heart Association indication. Kawasaki disease shock syndrome was defined by the presence of macrophage activation syndrome and circulatory dysfunction. Current or previous infection was confirmed by reverse-transcriptase quantitative polymerase chain reaction from nasopharyngeal and oropharyngeal swabs, as well as serological qualitative test.
There were 19 patients in the group diagnosed before the pandemic and 10 in the group diagnosed after the pandemic began. Children who were diagnosed after the pandemic were older on average (3.0 years vs 7.5 years), more had cardiac involvement (2 out of 19 vs 6 out of 10), more had Kawasaki disease shock syndrome (0 out of 19 vs 5 out of 10), more had macrophage activation syndrome (0 out of 19 vs 5 out of 10), and more required adjunctive steroid treatment (3 out of 19 vs 8 out 10).
Because their hospital saw a 30-fold increase in the incidence of Kawasaki-like disease, the researchers said that similar outbreaks should be expected in countries affected by COVID-19.
1. Verdoni L, Mazza A, Gervasoni A et al. An outbreak of severe Kawasaki-like disease at the Italian epicentre of the SARS-CoV-2 epidemic: an observational cohort study. The Lancet. May 13, 2020. Epub ahead of print. doi:10.1016/s0140-6736(20)31103-x