inner thigh rash scrotum peeling

need some advice guys I am hoping that this is not an std, but recetly i have deveopled a rash on my inner theigh that itches from time to time, it is not really bumps but they are cirular and white not painful and are kinda scaby, at the same time I am getting like dry skin that peels from my penis shaft and scrotum, I have an acne problem and have been on antiboits for the past 2 years or so, and am using an acne wash in the shower, do you think that this is anyway realtead the rash came out of no where, I did have unproteced sex about last Febuary(2008) maybe but did never have an rashes or anythign like this till now (sept 2008) do you think that it is herpes, excem, filoiltious from the antibiotics?? thanks for the help and also I do not have any red bumps or rashes or anything on the penis or scrotum