On that point, this article is pretty good.
https://www.bbc.com/news/health-52648557 I won't pretend to suggest to know why this is occurring, nor can I exclude that it won't become more prevalent. It appears to show up weeks after infection, suggesting it lags the curve substantially and we could see it blow up. Otherwise, though, it seems like we're talking about something like 50 kids who had it in New York and who tested positive for COVID-19 antibodies, and 30 who weren't positive. Almost all those kids recovered, too. New York apparently has had 340,000 cases of COVID-19 confirmed, and millions more are estimated to have had it. One hears "50 kids have a weird rash that some think is caused by the virus that causes COVID-19," and that may sound like a lot and be alarming, but compare that to 340,000 cases of the disease, and 20 million people in the state, and it's just not very prevalent at all.
Yeah, I could write 85 overly wrought lines about how terrible it is for any kid to have this disease, and yes, of course, I wouldn't want my kids to get it. But 10 kids a day on average in the U.S. die of non-boating related drownings. 400 kids a year die from being hit by cars, and many more are hit by cars and injured but recover. You get the picture. Someone better than me at appealing to emotions and messaging will have to figure it out, but we can't let a tiny fraction of ordinary-course illnesses, deaths, etc. completely destroy the country.