Adult-onset Still's disease (AOSD) is a form of Still's disease, a rare systemic autoinflammatory disease characterized by the classic triad of persistent high spiking fevers, joint pain, and a distinctive salmon-colored bumpy rash. It's closest related to arthritis.
I see a rheumatologist for it but she only has had 1 or 2 patients with it.

It’s very rare but can cause swelling and joint destruction like RA. Can also inflame the heart the liver spleen and cause problems there.

I don't know What Stills Disease is...can you explain what it is.