hello Marilyn..thanks for your query..
I feel that you have something knows as Urticaria
.It is common condition with frequent exacerbations and remissions.In most cases,a direct cause is not identified.However a combination of correct anti histaminic tablets for a few months help in reducing the severity and frequency of these hives
Start application of a soothing anti pruritic calamine
lotion to relieve the itch.In certain cases a few bood tests are advised to rule out ant internal causation of the same.You have not mentioned the dosage and duration of prednisone
you are taking.In some cases a higher dose and a gradually tapering therapy is required.Do not worry,although symptoms and treatment course of urticaria is prolonged,these do not pose any danger in most people!
hope this helps!!take care...