L.W.
My children had this sort of problem to varying degrees. It's normal. Gently rub baby lotion into it a few times a day and after baths. It will go away eventually. I was told that it's perfectly normal. Babies have all sorts of pimples etc. the first year as their skin adjusts to life. I was also told to use one of those soft baby brushes. If it's also reddish, like someone else suggested it could be ring worm. Which isn't actually a worm at all, just something similar to athletes foot. Lotromin will take care of that. That's what the pediatrician gave me when my son got it on his leg.