Jamieson, Fausset and Brown on 2 Kings 2:23-24

23-24. there came forth little children out of the city--that is, the idolatrous, or infidel young men of the place, who affecting to disbelieve the report of his master's translation, sarcastically urged him to follow in the glorious career.

bald head--an epithet of contempt in the East, applied to a person even with a bushy head of hair. The appalling judgment that befell them was God's interference to uphold his newly invested prophet.