Has anyone had these before

I keep getting rashes on my boobs. I am only finding them on my boobs this one is just above my nipple. I had one higher up on my chest and the other in between my boobs. and they itch horribly. I haven’t changed any lotions or shampoos or anything. I thought maybe it was just like heat rash because I get that easy but I haven’t been hot. The first picture is once the rash goes down and the second is the worst one I’ve had