Oh sweet girl! Is there anything more pitiful than a baby in a hospital gown? Sounds like Justavirus. Frustrating to not know what it is, or how to treat it. One of my daughters used to get a very high fever whenever she was sick. She was hospitalized twice with an illnes that was just a high fever. Both times we heard a lot of mentions of Kawasaki's disease, I'm guessing you did too. But after days of fever and oodles of tests, the fever broke and all was well.