clear white blisters

Over the past year, I have noticed very minute, clear blisters on the head of my penis.  They have yet to break, and do not itch or cause a burning sensation when I urinate.  I went to my GP approximately four months ago.  He advised that it did not appear to be an STD, but never collected a blood sample for further testing.  I have been with the same woman for the past three years, who has been tested for STD's and found to be negative.  Although I have not been with anyone else for the past three years, I have had other partners in the past.  Over the past six months, I have noticed an increase in blisters on the head of my penis.  If the blisters do not sound like genital herpes, do you have any thoughts about what they may be?

[gracefromHHP]

You might want to change your gender here - you are showing up a pink icon which means female ;)

Clear blisters that have been there for a year and haven't broken 1 aren't blisters and 2 aren't due to herpes.  If your regular doctor isn't able to figure this out - consult a dermatologist for a further work up.

grace