My experience with hives began June of 2015. UV light on a hot, sunny day reacted with the warfarin that I take and caused the typical red welts and extreme itching on my forearms, neck and one ankle. The reaction may have been to the dye used in warfarin.
The dermatologist was useless. What worked for me was apple cider vinegar, activated charcoal capsules, and coconut oil. I also used supplements of DAO Histaminase and Quercetin. Cold ice packs on the affected skin followed with coconut oil helps reduce the itching.
It is my belief that hives isn't caused by a particular food or substance per se. Rather, these things function as a trigger to an overloaded immune system that is dealing with a lot of toxins in the body. I am 67 and have had time to accumulate a lot of toxins. As the charcoal and ACV cleaned out the toxins, the rash and itching went away.
Detox will be a regular practice for me from now on.