I have a quarter sized red bump on the back of my shoulder, the middle is yellowish skin (and is very squishy, the size of a dime), and the out side of the circle is red (and very hard in comparison to my surrounding normal skin). It used to hurt, back when it was mostly red and hard, but now it doesn t hurt, but the skin on the bump is peeling. Its been there for a month and a half now. When I first noticed it, it was just a flesh colored lump that I assumed was a cyst (but there was/is no head), I carried a heavy back pack that irritated it, that i think caused it to become red and scary looking. It only began to look red when i took the back pack off (this happened a week ago). I just want to know what it is and what i should do.