Autoimmune is connected (they always love more at the party), but some diseases are linked (like eczema and asthma, Crohn's and fistulas, UC and PSC or ankylosing spondylitis...etc). Many of these diseases come with other manifistations as well...definitely linked, but secondary.
With the above, controlling one can help in controlling the other.
With separate autoimmune, controlling one sometimes won't control the other unless with immunesuppressing meds....it could help across the board. Not necessarily controlling all, but giving the entire body a break, so to say.
It all sucks to have autoimmune issues, and sometimes the added stuff can be worse than the original offenders.
It was suspect that I had Raynaud's...I do have my hands reacting to stuff in that fashion, but stress is the contributor in situations. Biofeedback has helped with it, and they do calm quickly now compared to before...which progressed to anxiety attacks.
I have a friend who has fistulising Crohn's...AND Raynaud's of hands and feet.
q