Thanks for your query!
May be its mild injury
If there is no fever
, or secondary infection etc , you can wait,
I would advise:
Whether he has be vaccinated for 16-18 month (booster DPT
Keep wound clean.
You can apply antibacterial cream on wound.
On safe side you can do X- Ray Skull
I wish for your child speedy recovery
Regards; Dr Sagar Mhatre