Has Parkingson's Disease Been Confused For Lupus Or Vice Versa?

has Parkingson's Disease been confused for Lupus or vice versa? I was diagnosed with Lupus in 1983, I was 17, I am now 54 and am under treatment for Parkinson's Disease and RA and the symptoms for Lupus and these other two conditions are very similar and has got me thinking now if I'm being treated for the right condition. What specialist should I be talking to about these concerns?