acetic acid test

I recently noticed an oval 3-4 mm. slightly raised lesion with an uneven surface on the shaft of my penis.  My partner denies a history of STD of any kind.  My internist examined it and thinks it is a seb k. but I am concerned about HPV.  I soaked it with 5% vinegar for 10 minutes and it turned very slightly white.  Soaking it with plain water for the same amount of time did not result in the same slight color change.  How white does a wart have to be to be considered positive?  

Thanks.

[Alan Rockoff, MD]

Vinegar is an unreliable test, as it often turns white things that aren't warts.  On the other hand, when people get what look like SK's (seborrheic keratoses) on the penis, they may indeed be warts.  If so, you may have contracted them years ago from a previous partner.  Either way, you should ask to have a dermatologist of STD specialist check you out.

Best.

Dr. Rockoff