Oh, the itch
Stupid things like fruit eg fruit with stones or oranges can give you hives. I now cannot eat stone fruit, oranges or have orange juice as I come out in hives. I had them once so bad on my legs that it liked like i had measles.
Make a list of everything you have eaten over the last week and which day. The Dr will also ask this question. Sometimes looking at it will give you an inkling to what might be causing the problem.