My backside, starting below my neck, all the way down half my back, is about 60% covered in little mini-pimples. It doesn't hurt, nor are any of them big, but it just broke out randomly overnight with no warning and i'm kinda scared as to what happened. Any ideas before I take a visit to the doctor. This has actually happened once before, but the problem went away within a couple of days, which i'm hoping happens to this too. But i'd still like ot know what the cause of this could be