If I was you, I'd get a clean piece of kitchen towel and dab gently at the little chick's wound. Then sniff the kitchen towel. If it's infected, you'll smell it straight away. If it's not infected, I'd say do nothing, just keep a close eye on the chick. Chances are it'll heal up fine on its own. If it's lively, eating, drinking etc, it sounds like it's most likely okay. But if it IS infected, the dab of iodine idea sounds good. I'm assuming it's okay to use iodine on chicks but I'm not sure, so might be a good idea to ask on here just to check.