I have this same thing happening to me. It's already been 1 month now. When I first started getting them, they would happen everynight around the same time, within an hour. Benadryl... to the rescue, but it takes over an hour for them to kick in. I walk around, wondering what causes them... looking high and low, wondering if I ate something, but every night, same thing... 2 weeks ago, my doctor prescribed me prednisone dose pack, didn't work for the first 3 days, but then it worked for the last two.... after that they're back with a vengeance, only now at different times of the day. I keep looking at the food that I eat, to see if something is repeated that causes this ailment, but I'm bad at writing things down... so it's hard to limit things, but I keep on feeling in my head it has to do with laundry, or a cleaner. My girlfriend cleaned the couches (we have a dog that has a problem with his butt gland), and she used this new product. I emailed the maker of it... and they said that some of the workers when they come in contact with the product have had rashes that have lasted for a week, but he said it was HIGH DOSES of this... but anyway, I think it might be the residue of this magic cleaner that is killing me slowly. When I get these hives lately, they seem to be getting worse. Now I have horrible chest pains and I can't breath easily, HIGH PRESSURE... HIGH PAIN, and I feel like I"m having a heart attack. I'm going to the laundromat tomorrow, to wash all my clothes. I'm going to throw away all the pillows and couches that my girlfriend cleaned with this cleaner, and I'll fill you in on the results. I was almost on my way to the hospital tonight, but I fought off the pain, and the benadryl is finally kicking in. Now I find myself sitting on the internet, looking for some kind of answers, hoping to see something, but for everyone the problems/causes all seem different, and no one ever seems to have an answer. So with my limited budget right now, I have to remake my living situation, hopefully it works. We'll see.
(me with hives)