Is there a Dr in the house- ? about crack cocaine

[Anonymous]

A bunch of us were out the other night sitting in a balocny type area and on the ground floor there was this guy sitting who had this like....... crusty/boily/warty fungus looking stuff on the back of his neck. A friend we were with told me that she though it could be from crack because she previously worked with a lot of crack addicts and said that a lot of them had that shit on their skin. She heard from someone else that they were sort of like... calcium deposits, but crack deposits in the skin because the body couldn't process all the crack.
Anyway I looked online to see if this was true or not and haven't found anything. I have to know
Also she said a lot of the crack addicts were missing their two front teeth. Why is that?
Does anyone know anything about this shit?