u/BlueberryLevel9942

I just noticed this patch of discolored skin on the nape of my neck the other night. My mom saw it while she was helping me self tan my back. The last time I self tanned was probably 8 months to a year ago and she would have said something if she had seen it then. I’ve only tanned outside a few times within the last couple of months when weather permitted and I never turned over to tan my back. I also wear my hair up quite often and feel like someone would have noticed it in the past which is why I think it must be somewhat new. What could this be? Should I be concerned?