I have this on my bikini line as well. Had it since 3 months old and not in my 20s. It hurts, itches and causes a lot of personal and relationship issues for me. I was told when I was a baby that it would be major surgery to remove, and even then it could come back. I'm now starting to look into if this is still true or not, but for sure, it does not go away unfortunately.
I just took my 9 month old to a dermatologist today and he told me that is what it is. It is located at the top of her thigh near her bikini line. He said we should just leave it alone. How long have you had it and does it itch you?