What Causes Itchiness And Pinkish Spots On Arms And Back?

I have used crack for a while. About a month ago I started feeling itchy at night and I see a lot of tiny tiny pinkish spots on arms and back. Just started seeing o few on neck. Like 3in a row. Back dud feel like it was breaking out and crusty. But not anymore. Googled diseases and scabies came up but I don't sleep around and other symptoms I do not have.