Red sore under bandage, no idea what it could be?

A child I know broke a finger over a month ago. After the cast came off, the doctor said he should keep that finger bandaged to it's neighbor finger as a sort of splint. Everything was fine, until a few days ago. Several red areas showed up along the fingers, under the temporary bandages. The sores barely hurt, don't itch, aren't open, and a few are going away after the parents began using gauze under the sports tape(which the doctor had never mentioned doing). There are still two left, any idea what this could be? The doctor is over an hour away, and the parents aren't worried, just curious.