Thanks for your post.
4 months ago, I accidentally stepped in an ant hill in Costa Rica, while on vacation . Needless to say, I reacted with localized hives and itching, on the offending foot clear up that leg. 2 weeks later (I had long since returned home) I was STILL reacting, and given some prescription antihistamine meds/cream. Now, here I am 4 months later, and the hives and itching have become more and more frequent... lately, an almost daily occurrence. It gets worse at night. I never know where it will start (patches on my shins.... upper arms...shoulders..... ankles, knees, scalp, etc). The more I itch, the worse it gets, of course.
I should note that I also have autoimmune disorders (hypothyroid disease among them). I think my immune system has gone WHACKO!