Spots on my stomach and back?

Since the beginning of April i have spots on my stomach and back. It is like a different shade, a bit darker, and it reaches from my sides through out to the front of me (my stomach) and my back. Both of the shades are separated by spots... darker and lighter...





What can this be? Some people tell me this was caused by using a bad lotion while going to a tanning salon. If anyone might have any suggestions please let me know. I am very worried. Thank YouSpots on my stomach and back?
i go to a tanning salon... and about a month later going tanning about twice a week i got a white spot( now I'm real tan) on back... and i think it is the lotion... you gotta make sure that you cover you whole body with the lotion... you might of missed a couple of spot... i hoped i helped!!!

gloss