A picture would be helpful, but it could be a number of things, bug bites, possibly if they are very itchy, but they could also be hives as well. Since the chicken pox virus never really leaves your body, you could Shingles, which is much worse. My mom had it on her back and the sores were very painful. For your sake, I hope it's not that.
Whatever it is, as long as it doesn't get worse, you should be okay, but if you are in alot of pain and it starts spreading, I definitely would see a doctor.