Hello.  I have a brown bump on my back.  It appeared as if a balckhead was in the bump so I squeezed it.  Brown (what I assume to be puss) came out  and it seemed to be quite a bit.  The bump did flatten some once I squeezed some of the puss out.  I squeezed it and more brown puss came out but no bleeding.  Seems to be a lot of puss.  The bump is about the size of a dime.  What is this?
Thanks for your question on Chat Doctor. By your history and description, you are mostly having infected sebaceous cyst. Back is the most common site for sebaceous cyst. It is skin swelling in which sebaceous cyst are enlarged due to obstruction in the sebum flow. So sebum accumulates in the cyst and enlarge. This sebum can get infected and cause pus formation. The most common association is diabetes and poor skin hygiene. So better to get done sugar level to rule out diabetes. You need surgical Chat Doctor.  You also need antibiotics and anti-inflammatory 