About a year and half ago, on the head of my penis developed a red, painless rash. The sides of the head of my penis would become irritated and slightly inflamed after sex or masturbating, but other than that I had little discomfort other than the usual psychological freaking out that comes with something like this. Around the same time, I developed a fungal infection in my groin that thankfully was cleared up with an antifungal, but the rash remained.
I saw two separate physicians about my problem fairly early on. One diagnosed the fungal infection. After that, school began and I started seeing my university physician. She seemed unconcerned about the rash and the mild irritation. At the time, I'd been with the same partner for two years (I'm still with her), and there didn't seem to be any indication the what I had was sexually transmitted. However, she tested me for Gonorrhea and Chlamydia, and, at my request, a herpes blood test was done a few months later. I saw her over the course of two semesters, and she remained unconvinced that I had any significant problem. My girlfriend saw her doctor at her university, and they could find nothing wrong other than a pretty bad yeast infection.
After school let out for the summer, I began seeing a local urologist to see if he found anything abnormal. He felt it was probably a skin condition, and wasn't worried about it. However, over the summer, below the head of my penis became rather tender and sore, and sometimes burns after sex.
From the research I've done on my own, I haven't been able to figure what I might have. The fact that I've been with the same girl for 3 years and remained faithful doesn't help pinpoint anything either. I know its foolish to think I can get a diagnosis over a message board, and that's not what I'm expecting. However, any help would be greatly appreciated.