I have told a couple of friends. One ignored it when I brought it up, and another treated it as if "Aren't you over that yet?" I've let those people fade out of my lives.

Another friend has been really understanding; I'll tell her when I'm having bad symptoms. The fourth person I just told (she was wondering why I was missing so much work--doctors' appointments), but she has noticed and been very accepting of my symptoms, so I think giving her a reason for them won't change things much.