I think we need more information. The workup is well described here, and I agree with their consideration of JIA vs. rheumatic fever vs. oncologic. But Im hoping theres more information than this. What did they ultimately diagnose her with when she was sent home? Did they do anything to treat her (i.e. IV or oral steroids)? If they did treat her, did anything help or improve her symptoms at all? Is she following up with any outpatient specialists? Again, their workup sounds thorough, just seems like some info was left out about what they actually did to treat her.
As soon as they mentioned the salmon-colored intermittent rash I was like STILLS! Very rare but once you've seen it, you never forget it. Anakinra injections worked great for the patient I worked with, along with a major organ transplant due to damage done by the disease.