Tried benadryl, (diphenhydramine) zyrtec & allegra. i get extremely dizzy with brain fog from all of them. is there anything else to try for chronic idiopathic hives?

Yes: Try Loratadine or Xyzal (levocetirizine) and see if you can tolerate them. Do note that the side effects tend to decrease after you have taken an antihistamine for a week to 10 days.

Alternative Meds: As hives often has a strong emotional component, consider some of the following psychiatric meds that have an antihistaminic effect along with an anti-anxiety effect: Mirtazepine, Quetiapine and Doxepin. Although not FDA-approved for hives, experience has shown efficacy in some patients. Of course, always check with your doc to see if you're clear to take any of these meds.