Auto body repair & detailing: Humid air paint bubble, air paint, rear fender

Question
I have a very small paint bubble on the rear  fender of my show sports car.  Only comes up when the air is very humid or it has rained - area in question was repainted 7-8 years ago due to minor accident, bubbling just started recently.  Car is very well maintained, never driven in winter, etc -- so don't think this is rust underneath?

Read at another web site that bubbling likley due to small microscopic breaks in paint causing moisture to enter (and expand when heated by sun).  Is there any good way to seal up the paint (clearcoat) to stop this?  I realize this couldn't be done until weather was very dry and bubble had gone flat.  

Trying to avoid a full repaint or spot repair due to color match issues since rest of car's paint  is nearly flawless.  Thx!

Answer
You could use some touch up paint and dab the area in question. A good tip is to use the back of a match from a book of matches and trim it to have as fine of a tip as necessary. Wait until it is as dry as possible. If it is a very small spot then maybe you might want to pick the bubble and then touch up with paint. After the paint is  dry you can water sand with 2000 grit wet paper and buff to knock down the touch up area and make smooth.
          Thank you for the question!
          Ken