I haven’t found much published medical literature on the subject of a relation between T1 and various hives but certainly there has been anecdotal evidence.
I myself went through a phase of this when I was in college and seemed to be associated with parts of my skin exposed to the cold. Maybe Cold Uticaria, which is actually kind of common in college age folks who don’t have T1. After that phase it’s never re-occured for me.
Antihistamines provided me some relief but it wasn’t total relief. If they are in a small area then something like Benadryl anti-itch cream may help.
There are some conditions that are associated with bumps, like Lyme disease, that are actually helped by antibiotics. Was your doc thinking along those lines, that it might be Lyme disease or some other insect-born bacteria? I had Lyme disease too! The antibiotics worked wonders on all the awful things Lyme disease caused.