Hello doctor, I got burning sensation on perineum running from anus to genital when I get erection and also some kind of swelling happens right there under it when erection happens. Also legs get tight and I had that burning sensation, no problem urinating.  Little scratch around one side my anus at first for months now it turned into a small pimple thing  Also I get little spark type feeling on my genital. I still can't identify I am healthy how I got this. It's been 4-5 months facing this.