Doctor,
This actually happened to me years ago but I'm still somewhat concerned about it and have always wondered and wanted a professional opinion.
I am a 24 year old male.
Anyway, about three years ago I had oral and vaginal sex. Both with a condom and it was about the first time I had sex. After two days my penis head got a very itchy, red rash. I went to the doctor and he prescribed Viaderm KC ointment. The rash went away; then, about a week later the area where I had the rash and where I applied the ointment became itchy and started to blister with sores. The moment I noticed the sores I went straight to the doctor again and he took a swab to test for everything. He didn't quite understand it since I used condoms.
I waited two weeks for the results. I tested negative for everything, including herpes, which is what my doctor thought it was. Afterwards he said not to worry about it and that if it comes back to come and see him again, because then it actually means I do have herpes but the swap didn't pick it up. However, I know that as long as you go to the doctor within 48 hours of the blisters appearing, the test is fairly reliable. That's exactly what I did.
It's been three years since then. No genital sores whatsoever or rashes. I do get rarely cold sores on my mouth, but I presume I picked up the virus when I was a kid as both my parents and brother have had cold sores.
My question is: what could it have been? Were the genital sores an allergic reaction to the ointment? Or possibly the condom? I use condoms always and have never had a problem with them since. Sometimes I think it was HSV-1 and that the girl may have given me genital herpes orally because she did kiss my penis before putting on the condom for oral sex. Then again, other times I think I just think about it too much.
I've also had unprotected oral with girls, some of them for years, and they've never had any problems.