What Causes Red Bumps On The Bump While Having Syphilis?

So a couple of months ago I noticed 2 nodes in my groin swollen and subsequently one in my neck that was also swollen. I made an appointment, because at the time I had what I thought, and a colo-rectal surgeon said was a fissure. So I went and got tested for everything but herpes and it turned out I had syphilis. I received 3 penicillin injections (the last being 2 weeks ago) and told my partner to get tested and treated as well. He said his test came back negative and his dr told him not to get tested, but now he has symptoms so he got treated and I received a precautionary extra dose. However, I have noticed a small group of red bumps on my back that are a little tender and my nodes still have not subsided. I m nervous because I haven t been tested for herpes, and my dr wants me to get a lymph mode biopsy of the one that is on my neck. This seems alarming to me.. Could the syphilis be the reason for the nodes still being inflammed or could it be something else?