Bull's eye rash with treatment?

Just curious....does anyone get, or had anyone ever had a bull's eye rash during treatment? Ever since I started treating, back in November, I got a quite large (about 3-4 inches in diameter) bull's eye rash on the inside of my arm. My LLND tells me that is the Lyme coming out as we treat and get the bugs coming out of hiding. Just wondering if anyone else has experienced this?
Thanks in advance! First time posting question...

Thanks goshawk! I will check out the info. Ugh..never thought of it as a new bite, but it only started happening about two weeks in to treating with a Buhners type protocol (Called Tick Attack). Rash then faded out and came back a few weeks later when I started on an immune boosting protocol. Then left again and came back again worse yet about a month after that (just a few weeks ago) and now has faded again. I have started back on the Tick Attack and will take it for the next three months, so it will be interesting to see if it comes back again. Thanks again!

My LLMD had the rash reoccur on his torso. He said it was all over his stomach, sides and part of his back.