What is this large swollen thing on my boyfriends face underneath a pimple and how do we make it go away?

My boyfriend had a pimple on his face below his mouth on the left side for a few days. He picked at it and now underneath there is a hard, swollen ball of something just a bit smaller than a golf ball. It is painful to the touch, presumably because of the pressure of the swelling. Does anyone know what this is or how to make it go away?