What Causes The Outbreak Of Hives On Legs And Arms?

I am a male 50 years old and have broken out in hives on legs arms head ears wrists and I went to Dr. got a shot and i am using benadryl with cortizone lotion and it seems to go down then pops up in another area the next day i feel like the hives are in my chest throat not having breathing problems but the itch burn and pain is horrible its been 7 days?? What else can I do I have not eaten or changed any products in the house hold? I also was just diagnosed with hepetitis C but have not gotten to the specialist till the 16th of march. could my medications with the hepitiis C be doing thisHive problem?