Suggest Treatment For Small Itchy Bumps On The Buttocks

This is a dermatology question - I have 6 - 8 small itchy bumps on my inner buttox that I have been treating with Tea Tree oil. They go away for several weeks only to reappear. They usually never get larger than a centimeter or two, but while I was deployed to Afghanistan one turned into a cyst, was lanced and treated with antibiotics, and again several weeks later after the wrong antibiotic was prescribed. However, since then, and with the tea tree oil treatments they have stayed a fairly small size. How do I get rid of them for good?