Yes! I have had awful bouts of urticaria - a few months long. Mostly in summer, but am having a bout at the moment. It was just terrible - massive hives all over my body, occasionally swollen eyes or lips, dreadful itching. Every single day for months. I had tried all kinds of antihistamines and nothing was working. No idea what causes it. A specialist recommended I try a combination of two drugs: Cetirizine (normal antihistamine) and Ranitidine (the generic name for the drug often branded as Zantac).
Now it seems a bit odd to take Zantac, as it's an antacid type thing, used for indigestion. But apparently it has a kind of side-effect of working on another type of histamine receptors in your body which normal antihistamines don't work on (or something like that!).
Anyway, to cut a long story short... I started taking them (one of each tablet, once a day, but you can take the Zantac twice a day if it helps), and after two doses the urticaria was gone. Totally. Like magic. I kept on taking them for a while, then occasionally tried skipping a couple of doses to see if the urticaria came back. First few times, it did come back, then one day I stopped taking the tablets and no more urticaria.
I don't know if it works for everyone, but you can get both tablets over the counter, and they are pretty mild non-problematic drugs as far as I know. Worth a try!