BILSTERS ON FINGER TIPS IN CHILDREN

I have a 5 year old for the past 6 months he has been getting tiny blisters under the tips of his fingers (all 10) then he says it's itchy and bites the tops of his fingers which is causing all of his skin to peel away.  Right now it looks like he is sheding his skin.  He has had this in the past but I didn't make a big deal out of it.  It always went away, but now it has been along time for him.  I took him to his doctor and he didn't know what it was.  They suggested that I take him to a dermotoligist.  I have not made the appointment yet.  I just took him Thursday.  I also have seen them on his big toes.