What Causes Severe Itching, Hypersensitive Skin And Joint Pain?

My doctor thinks I had an allergic reaction to augmentin and gave me 10 days of prednisone. The severe itching as cleared up, though I still have hypersensitive skin and my face feels flushed. Now (2 days after finishing prednisone) I have severe joint pain, but no swelling. I think I am still suffering from an allergy - any suggestions for finding the cause, or treating the symptoms? I am recently menopausal 50 yr old woman otherwise in very good health.