What to do for chronic Hives?

What is causing my hives?

• In the last two months I've had a breakout of hives mostly on my back (but a little on my legs and arms) four times. Each time I first notice it in the middle of the night - about 3:00 a.m. - as the itching wakes me up. The hives respond to Benedryl. I have eaten different things for dinner and lunch each time with seemingly nothing common - and certainly nothing out of the ordinary of my usual diet. It doesn't seem to be a contact allergy because the parts of me touching the sheets aren't necessarily the parts that have hives (ditto with my clothes). Some parts touching clothes have hives, some parts just touching sheets have hives, and some parts not touching anything have hives. Plus, this has only occurred 4 times over the last eight weeks and if it was a contact allergy, you'd expect me to have it every time I touch something. I can't think of anything else that was distinct about what I ate or touched on those four ocassions. The first time I had hives it was preceded by stomach pains, but it might have just been a coincidence because I didn't have stomach pains with the rest of the times. The hives go away in about 20 minutes once I take a benedryl (and actually go away on their own after a few hours if i didn't). Any possibilities?

• Answer:

  What did you just say?! Be of the parts? Why would any1 be of the parts anyway??