cold sore question

Hello Dr. Rockoff,

For the past week or two my lips have been chapped. Not bad, however, I know they are feeling a bit rough (like dry skin).

However, yesterday I noticed a little blister looking bump on the middle of my upper lip. I took a picture of the location (blister was already gone).

http://f1.pg.photos.yahoo.com/ph/rook_pup/detail?.dir=/26ca&.dnm=efed.jpg

It did not hurt nor was my lips irritated. It popped (or went away) on its own later in the day and left a little pin size scab. The little scab went away as well later in the evening. I had some dry skin at the same location a few days before. Could that have caused it? Today I seem to be fine (The picture was taken earlier today). My lips still feel chapped, again not bad.

Does this sound like a cold sore to you? If not, what else could have cause this? I have been pretty stressed out for the last couple of weeks which I thought might be why my lips are chapped. Plus, I am worried it might be a cold sore because I had a high risk exposure to a stripper (protected sex) about 15 weeks ago and she kissed me on the lips several times. I did not notice any bumps or blisters on her lips.

Thank you for your help!!

[Alan Rockoff, MD]

Hard to be sure from the picture, but cold sores don't go away in a day.  Also, if you catch herpes of lip, the first attack is much more severe--swelling, swollen glands, fever, and so forth.  And the incubation period is a few days, not 15 weeks.  So on many grounds, I don't think you need to worry.  As to what exactly caused the blister, it's hard to say.  If it recurs, have a doctor take a look.

Best.

Dr. Rockoff

[rook_pup]

Just a couple more more questions. Would a cold sore stay for less then a day?  Plus, if it was a cold sore from this girl, wouldn't I have noticed it before 15 weeks after the exposure?

Thanks again!!