### Human:\nhow long will hives and itching last as a result of an allergic reaction to sulfa drugs?\n\n### Assistant: this will typically depend on your individual body's response as well as the dose of antibiotics taken. hives and itching can last anywhere from a few days to a few weeks in my experience. if you visit your physician they may prescribe prednisone which will relieve the symptoms and likely make the hives go away more quickly.