I do suffer from patches of psoriasis, i have Hashi/Hypo, mine is still here even since starting thyroid meds.My brother has it really bad all over him but no thyroid problem.With one auto-immune disorder your chances are high for another..
Well, I've had psoriasis since I was 9 years old and the strange thing is that I had Hashimoto's thyroid along with a nodule that couldn't be ruled out as cancer so my endo advised removal of my thyroid..which I did Dec 09. After that..my psoriasis went completely away!! The endo told me that as soon as I was close to my optimal dose of Synthroid that the psoriasis would return and sure enough, it did! Psoriasis is an auto-immune disorder. You will want to do further research. Hope my story helped! Good luck!