Try some salt water soaks with very warm water. I use a shot glass. Just be very careful since it is a blood blister-do not lance it-you don't want an infection. If you do the salt water soaks immediately before (to soften the blister so your little one can help relieve it) and right after to just help it go away. The fluid within the blister will move into the salt water. It takes a few times, but you should feel relief after a day or so. Don't soak for more than a few minutes.
Let me see if I can find the link on kelly mom:
treating blood blisters
Let me see if I can find the link on kelly mom:
treating blood blisters