All right guys... here goes... four days ago, I had sexual intercourse
(vaginal) for the first time.  I was with a girl I trust to the utmost,
who is using birth control, and as such, we didn't feel the need to use
a condom.  The next day, I developed an irritation on the area of my
penis covered by my foreskin (just below the head).  It is reddish and
spotty, and is slightly itchy and sore.  I saw her again today, and
although we didn't have sex, the irritation seems to have spread onto
the head as far as it is covered by the foreskin.  Is this simply
normal from the friction involved in having sex for the first time?  Or
is it possible I've contracted something that my girlfriend didn't know
she had?  Is there another possible cause for this irritation?  Most
importantly, what can I do to treat it?

Thank you,
-Hukuis