Hi. I am a 27 year old and I have had psorasis is I was 7. I don't know about diabetics, but for me the only thing that seems to work is Methotrxate. I can't take antibiotics, I'm allergic to them. I hope this helps you. I know what It's like to be completely covered. It's miserable and embarrassing. It's nice to know that there's people out there that I can relate to. Good luck.