HI AUNTY ~ I used to get bad hives too, esp as a kid and teenager; sometimes, they were as big as an apple -- big round red blotches on my arms, legs, and stomach. I also get some of those itchy ones and they are often caused by things like wool, mohair, and different kinds of soaps and perfumes. They weren't sure what caused the big ones, but thought maybe stress or anxiety ...
Anyhow, hives are hives and no fun; so they gave me CHLORATRIPELON (sp) pills and they worked wonders for me -- always took the worst hives and itchies away. These are hard to find these days though and one that is close is BENADRYL allergy pills and they work OK too. You can also get a prescription for something similar too, but not sure what it is called.
One time I got a bad reaction to a sunburn; hives all over my back and man did that burn and itch like crazy -- the doctor gave me a strong prescription that took them right away. This may not be caused by the same thing, but they might work well enuff that you wouldn't have to take the steroids which I hear makes people so hungry that they overeat and then gain weight.
Hope you find something soon ...