Excessive licking can occur for many reasons. Medical issues need to be ruled out first. My recommendation would be for you to visit your Vet to rule out any neurological issues. If neurological issues are ruled out then I would tend to believe that the licking would likely be due to anxiety. This is actually more common than one would think.
Dog anxiety is usually caused by lack of exercise. Think about yourself. Aren't there times when you truly need to release energy, to exercise, to get out of the 4 walls of your house? Dogs are really no different!
Your baby is obviously fixated on licking. Try a few things. Engage in your pet more. Exercise in the forms of walking and/or playing with a ball or toy. Another tension breaker for a pet is Kong toy, available in multiple sizes at an area Wal-Mart or Target store. Purchase the kind that can be stuffed with goodies. Don't go broke buying the canned stuffing to squirt into the toy. Purchase a cheap jar of peanut butter, stuff the Kong toy and put it in the freezer. After it freezes, this toy will give your baby hours of entertainment! I keep 2 around and always have one ready and waiting. The best thing is that you can throw them in the dishwasher after each use.
I firmly believe that the combination of the above will offer great results. Go slowly with the exercise. Use gentle correction as well. A simple command of "no lick" can be used right along with the suggestions. Don't hit your pet though, this will only create more anxiety and isn't necessary.
