Crotch burns when foot is scratched

[focus2aus]

For as long as I can remember (back through childhood), it's been the case that when the sole of my foot is scratched or rubbed abrasively, I get a burning sensation in my crotch/genitals and sometimes the opposite leg. It's an instantenous reaction, almost as though I'm "feeling" the scratching/rubbing in other parts of the body, but amplified. The burning is highly uncomfortable but has been so consistent that for a long time I had no reason to think it was abnormal. It's most pronounced when I put my bare foot up on the edge of, say, a coffee table and drag it slowly downwards. The burning itself is hard to describe. It's more like the feeling of extremely hot water where at first it's almost cool, though this feeling does not go away and become outright "hot."

Is this at all common? If so, does it have some significance? ... Whenever I mention it to someone they either don't get it or don't believe me.