What Does White Circular And Dry Bumps Imply On Neck And Back?

Hi my name is angela and IM 24 years old IM 6'1 and weight 255 lbs. The only medical history that i have is that i had hip surgery, other than that IM in good health except for my skin I have these dry spots that have these tiny little white dry bumps in a circular pattern. It started on my arms And now i have it on my neck and back I don't have alothat many