Itchy labia majora

Hey all, so over the past few months, I have randomly been having an unbearably itchy labia majora. It doesn't seem to correlate with anything like when I shower, what I wear/don't wear, or when I've had sex. It is only on the labia majora and nothing at all inside of that. It becomes so itchy that I feel like I am going crazy and it sends me into a frenzy like state where I cannot do anything other than try to find some way to soothe the itch. The first time it happened I had an oatmeal bath, which helped at the time but as soon as I got out (after 30-45 mins) it was super itchy again, but because I had itched so much it was really sore too. It then happened a few weeks after that, and just now it's happening which is a few weeks after the last time. There is no rash, and when I look at it in the mirror there isn't even any redness. My pubic hair doesn't grow there now because I've itched so much. Can anyone help me? I have no clue what it could be.