I have small white/red spots under the skin inside of my upper arms. Any information?

Hi, I had this same problem on inside of my left arm when I was about 10, I had been away with the school for a week on an activity camp thingy where all week I only washed once! (being a young boy haha) I went to the doctor who if I remember it was just an infection and I remember being given a cream to put on it that cleared it up, I still 8 years later have tiny marks like scars where they were but nothing anyone would see unless you pointed it out and looked close. Hope this helps :)