saddle sore? what is this?

Just last night after a ride, I noticed something strange on the inside of my upper thigh.  It is difficult, but the best I can describe it as is a pimple/ingrown hair only without any sign of a head or irritation at the surface of the skin.  Looking at the area where it's at, you would have no idea it is there.  It is very painful to the touch.  I have a relatively high threshold for pain, but If I apply any pressure at all, the pain is immediate and goes up to a 7 or and 8 in intensity if I try to do any more than lightly touch it.  I'm at a loss for what this is, the best I can come up with is saddle sore, but I have never experienced anything like this.  I have ridden the past 5 days here (avg 20 miles per ride) and it has been exceptionally hot (95+ every day) so that area has been exposed to some moisture.  The spot is roughly the same area of my thigh that would rub against my bike seat as I pedal. I've had weeks before where I've ridden twice the miles without any issues, so I don't know why this would pop up now.

Anyone out there have an idea what might be going on?  Any ideas for how to treat it?

Thanks in advance!

Eric