Sounds like Contact Dermatitis
of which [url="http://www.nlm.nih.gov/medlineplus/ency/imagepages/2190.htm"]Nickel Dermatitis[url] is one form.
I deal with the same thing, and honestly, I've found that the best thing is avoidance whenever possible. Now, mine does not seem to be as severe as yours - I had to switch to a leather banded watch, and I can only wear all gold or silver jewelry, but day to day minor contact doesn't usually bother me.
With my glasses, I foolishly bought metal frames without thinking about what would happen when the coating on the earpieces wore off - but a coat of clear nail polish fixed the problem, although I have to put it on about once a month or so. This might work for things like the back of buttons/snaps on your clothing or anything that touches your skin directly and you don't take off and on (I don't think it would work for jewelry for example).
I have no idea what you might do about razor blades.
Oh, and IANAD, and if you're looking for medical advice, you should see your doctor.