I'm 45 and have had spells of
this going on for about 10 years. In
both hands, usually the palm-side of
the fingers, but occasionally in the palm. I know when it's going to happen - can feel pressure, then it pops and you see blood under the skin and then it itches like crazy. Sometimes it's a hard blue marble under the skin. I have 3 that are permanently there (two in the same finger). It's almost never caused by anything - just happens. Occasionally it's when I grip something.