penis rash. what is it????

i have a pimple-like rash spreading aroung my penis and on the skin around my pubic hair. I've noticed this after i had consecutive sex with my girlfriend. She had multiple sexual partners in the past and had unprotected (without a condom) sex with them. We had unprotected sex several times that day, and on that particular day she happened to have her period. I want to know what this rash actually is. Could it be a STD or just irritation. How can I know for sure? Please try to respond A.S.A.P.  Should my girlfriend and I go to the clinic and get STD tests done on us? or is it something a little less servere?

P.S: My girlfriend never had STD tests done on her, and she is positive that she never had symptons like mine.

[H. Hunter Handsfield, M.D.]

Sounds like it could be a yeast infection.  "Pimple-like" always raises the possibility of herpes, but herpes rarely spreads into the pubic region and doesn't come on so quickly.

Both you and your partner should get checked, preferably by the same clinic or health care provider and at the same time.  The provider will take your histories, especially your sexual histories, separately.  You don't say how recently your partner (or you, for that matter) had other partners, so I can't judge the STD risk.  But every sexually active person who has changed partners or had more than one partner in the past year should be tested for common STDs at least once a year.  Don't delay too long; you should be examined while your rash is fresh.

Good luck--   HHH, MD