My Dr. Did A Swab Test On My Wrist On

My Dr. did a swab test on my wrist on a spot that I have had for over a month now. It started out very small and I had been putting Neosporin on it. It kept getting larger, So I decided to have them look at it. The results came back and he said it was a Staff disease. He called in Keflax 500 MG Which I started taking yesterday eve. It has gotten larger since yesterday and it burns Constantly. Is This Staff disease different than MRSA and how long will it take for the pills to start working? Is there anything else they can do? Is this contagious?