Small, painless, brownish rough patch on shaft of penis

I am a 30 y.o. heterosexual male.  Approximately 75 days after my last sexual encounter (unprotected), I noticed a very small, round, flat patch of what appears to be brown skin on the shaft of my penis.  It does not hurt or itch, although it does appear to weep or get moist if I have an erection.  It feels rough.  I do not notice any blisters or bumps and the patch is maybe about 1/4 centimeter wide.  I don't have any other symptoms that are associated with herpes - such as fever, flu-like feeling - nothing.  I had masturbated the night before but as a 30 y.o male with no sex for nearly 3 months, I had been masturbating a lot recently.  I am very worried about this but it does not appear to be consistent with any STD.  I am posting this approximately 10 hours after this patch has appeared and I know herpes can form blisters that appear and then burst, but would I be having this, a first noticeable outbreak, this long after exposure?

[Alan Rockoff, MD]

It does not sound like herpes.  it sounds like irritation.  I suggest you keep it moisturized, avoid rubbing it or examining it too closely, and show it to a doctor if it doesn't go away.  

Take care.

Dr. Rockoff