The development of a “severe itching rash” shortly after the ingestion of an antibiotic does suggest, but not prove, an allergic relationship between the two. In most instances, such an allergic reaction should have subsided spontaneously in less time than three weeks. My advice is that you make an appointment with your doctor or visit an urgent care clinic to get a professional opinion on the nature of the rash and appropriate therapy prescribed.
Good luck
Symptoms began occurring more frequently. Got a steroid shot. Relieved my symptoms for less than 24h. Any suggestions, as to how I can get hives/itching to go away?