How Safe Is Taking Vyvanse Instead Of Adderall?

I just started taking adderall xr 20 MG and caused me to break out. Because of tjis, I have now been switched to vyvanse. Should this help or is it possible to get the rash still? If the rash doesn t go away what do you suggest? I ve never had this problem when I was perscribed adderall a few years ago.