Should I be worried?

Hi, I have several light brown spots that have appeared in the last month on my left shoulder. They are slightly raised but relatively flat. I have done some research but have not been able to identify what they could be. I do take several medications, at least one of which could render me more sensitive to the sun. I also suffer from acne (mostly on my face) and dermographism but doubt that either of these would be related.

I have included a picutre. I know nobody can give me a diagnosis via the net, but I would appreciate if someone could tell me if this could be cause for concern... Oh, I forgot to mention, this is not an area that has been exposed to the sun this year.

Thank you!