Our son has a bump on his forehead. There's not scratch, just a bruise. Any remedies to treat the bruise which doesn't hurt?

You can apply cold compression (wrap ice cube in a cloth and gently tap on it) right away after the fall so the bruise will not swollen. Never rub the bruise as it will cause blood capillary to burst. After that, you can gently apply some zam bak on the bruise.