Maybe this topic should go into the health section.
When I was about 12 I had an eczema rash under my arm. I didn't want to cause a fuss so I didn't tell anyone. It was pretty bad though and very itchy. I think I had it for about a year.
A couple of years ago I got a similar rash on my stomach. I mentioned it in passing to my doctor while I was there for something else. He prescribed a cream, I used it for a week and the rash disappeared.
Why oh why didn't I say something as a kid? I put up with that rash under my arm unnecessarily.
I haven't had a rash down below, thankfully.