Why are there so many different treatment options for Still’s Disease?

If you have diabetes, your doctor gives you insulin. And if you have asthma, you are prescibed ventolin. Easy, right? But why are there so many different types of medications that are used to treat Still’s Disease? Why isn’t everybody just on, say, Methotrexate or Plaquenil or Enbrel? Why is there so many treatment options [...]