Thanks so much to everyone for the welcome and comments! DizzyDame: No, I haven't had a tilt table test yet -- my internist has me doing CT scans first to rule out adrenal tumors and the like. I had been wondering about mast cell activation disorders -- do you know if they're pretty much the same as mastocytosis? I believe I've already been tested for the the latter (blood tryptase levels?). The methylhistamine test seems ike something to look into. JaneEyre9: I've seen about five dermatologists (including specialists at the University of Michigan), all of whom are pretty much stumped. The only answer I keep getting is that this is something systemic, not dermatological. However, in the meantime, I was put on standard rosacea treatments to see if they could provide any relief until I got a diagnosis, but the antibiotics prescribed seem to make everything go haywire and I had similarly bad reactions to every topical. Some of the dermatologists recommended I go on to Mayo, so it looks like I'll have to end up going that route. I haven't had Lyme brought up as a possibility yet, though I've read a bit on it myself... From what I remember, it seems like most affected have an accompanying rash (bullseye pattern?), though I could be completely wrong about that. Carolyn: Unfortunately, this began months before I started taking a vitamin. I was worried about the niacin exacerbating the flushing, but was reassured by my internist that the amount of niacin in a multivitamin is too small of an amount to do anything. calypso: That's really interesting that the Effexor worked for you. I was prescribed it as a last-ditch effort after other medications (atenolol, neurontin, etc.) weren't touching the problem. I didn't see much of a change, but maybe I didn't stay on it long enough for any real effect -- I wasn't too happy with the side effects and quit it after a few weeks. Did you see an improvement fairly quickly? I got several conflicting answers from doctors about the length it takes to notice any real difference (initially I was told that since it helps the flushing and hot flashes of menopausal women quickly, I supposedly should have seen an improvement in a week; a second doctor told me it'd take at least a month). Thanks again, I really appreciate all of the help. Getting responses instead of just reading a list of symptoms has helped quite a bit already