Interesting Patient encounters, volume 2: A 19-year-old male with an "STD"

I was working in a rural county jail when this occurred. The patient is a slender, somewhat sickly looking 19 yo male. I did not ask what his alledged crime involved. The following is the harrowing account of how I came to diagnose his "STD" and my recommended "treatment."

RetiredJK: "When was the last time you were sexually active?"

Jailed Patient: "About 8 months ago."
RJK: "Did you use protection?"
JP: "No."
RJK: "Do you have sex with women?"
JP: "Yes."
RJK: "The occasional dude?"
JP: "NO!"
RJK: "You're sure? You are.... in jail after all."
JP: "Never."
RJK: "When did you first notice symptoms?
JP: "About a week ago."
RJK: "What kind of symptoms are you having?"
JP: "It's like a rash. On the side of my penis."
RJK: "Any painful discharge? Burning when you pee?"
JP: "No sir."
RJK: "Well let's have a look-see!"
(Examination reveals a slightly ulcerated, excoriated lesion on the right side of his penis; otherwise normal exam."
RJK: "Sir do you ever masturbate?"
JP (clearly embarrassed): "Uhh.... yeah."
RJK: "And you're right-handed."
JP: "Yeah (?)"
RJK: "Sir, I do not think you have an STD. Why don't you take it easy for awhile? Utilize your left hand when you return to masturbation. Or switch sides each time. This should resolve in few days."
JP: (relief)