Has anyone else experienced hives?

Hi, I was recently diagnosed with Parkinson’s and was prescribed Carbodopa/Levidopa. The day after taking it, I began experiencing a skin rash and hives. After several days, it had not subsided so I was referred to a pharmacist who specializes in drug reactions and interactions. After reviewing my symptoms and all my medications, he said he thought the rash and hives were unrelated to my medications (even though rash and hives are listed as possible side effects of Carbodopa/Levadopa) and that it was just urticaria so he prescribed an antihistamine (Xyzal).
I have been taking it for 3 days and it has not helped at all. Hives are spreading and itch so badly I can hardly sleep and is quite irritating all day.
Has anyone else experienced this and if so, how did you find relief? Thanks for your thoughts. Jim