I have what I think is a boil on my back. I ve been treating with warm salt water towels and antibiotic ointment daily, covered with bandaid. Today there are small bumps clustered near it, could a carbuncle be forming? The skin further outside seems irritated by the bandaids. It is located to the left of my spine on my upper back. I m going on a backpacking trip in 9 days, what should I do? Today is day 7 from when I noticed it.