i'm also a teen but i'm rarely in the sun or outside.
Me too, did you ever figure out what it was.?
Same here! We haven’t gone to the doctors yet though.
I have it in between and starting to go under my breasts and I think it is from the sports bras I used to wear all the time because I practiced volleyball every day. I don't go in the sun much now and they're there. They also don't itch and no matter what I do, I can't wash the spots off without making my skin raw and red instead of the brown spots. So it's not dirt. So, I'm pretty sure it is just a result of wearing a sports bra too often or any bra that pushed your boobs together.
Same I also have it and I'm in my teens. Please help