Four years ago I had protected sex with a woman (I am male) and 3 days later had a terrible burning sensation on my penis and testicles. No rash or discharge, just terrible skin burning. Since then, it has come and gone, but always been slightly present. Sometimes, however, it becomes intolerable. I have been tested for all STDs several times, prostatitis and herpes four times - always with negative results. In fact, the most recent herpes blood test was done in December 2010, with negative results for both HSV1 and HSV2. I have also visited a urologist who did no tests and told me it was probably not a urology problem. A neurologist did some minor tests but found nothing. There are no marks, no lesions, no spots, no discharge, no bumps or anything other than an incredibly painful penis and testicles. Occasionally it "feels" like there are cuts or tears, but there has never actually been any. Sometimes, when I am standing it feels a little less painful. When I am sitting, the burning can also be felt in the thighs. Do you have ANY idea what this might be or what I could try to alleviate it? It has been many years and I am at my wits end. Any advice would be greatly appreciated.