dark small blister on urethral opening on penis, dark red dots on opposite side I have a small, darkish blister near the opening of the penis on one side, and a small abrasion looking mark with 2 dark dots on the other side. There is constant irritation. I did have an encounter 4+ months ago in which a condom was used for intercourse, but taken off for oral sex and a new one put on for more intercourse. Very vigorous intercourse. Possible chlamydia and gonorrhea were eliminated with appropriate medications. Been tested for syphilis as well with an rpr test which turned out to be negative, and was negative on an hiv test. No warts present anywhere. I did have what I thought was jock itch 2 months after the encounter. That was treated with anti-fungal athlete s foot cream. I did not notice the marks until recently, after the doctor prescribed Cipro, 2 500mg a day, for possible prostatitis. Starting my second week of that, no relief. Any ideas?