I have had acne problems for a while. But, it is finally starting to get better. However, a few of the acne bumps left behind hard bumps/knots. I have one on my face at the beginning of my eyebrow and 3 on my shoulders. The bumps are under the skin and it doesn't feel like anything is in them. They have been there for over a year. Only one of them are red. Is this a scar? How do I get them to go away? Will I have to see a doctor, and if so, what kind? Dermatologist or general surgeon? Also, how will they remove it?