Chronic Hives are back... I'm so frustrated! Any ideas?

Here's the story... I woke up with hives one day when I was 14 or so, had them for 6 years and went through every Rx, diet and test that the allergist suggested and he said can't help you. Sooooo, I took benadryl 24/7 for the remaining years, got married and moved and hives disappeared! for over 1 year. Nothing. THEN, last week a few hives showed up on my thighs, thought it was blue cheese, nope. They are now here to stay, everyday, night, so back to benadryl 24/7 and that still doesn't cure the itch most of the time. So I'm thinking to take milk thistle, I read somewhere that it cured hives by helping out the liver... I'm guessing it's something to do with my body or liver... any suggestions?