Back acne help? Strange spots appearing everywhere?

I just recently started to develop back acne and i'm not currently treating it besides washing it as best as i can. Lately these strange white spots have been showing up in my back and spread onto my pecks and arms, they are all about dime size and have little tint dots around them. They don't have a texture or anything so i can't give you and further information besides they seem to be spreading from my shoulders forward. Any idea what this is? Its starting to really scare me. I spend a lot of time out in the sun at the beach and seldom do i use sun block so is it possible i may have skin cancer? I'm really starting to worry :( any help?