Hi thanks for your query on health care magic.
I understand your concerns and it seems you have good knowedge of medicine,as you tried to rule out head injury
From the history described by you,it seems your child doesn't have sever head trauma
Just monitor your child for the symptomss you have described above,if he develops any of above symptoms he shold be taken to emergency room.
You can apply cold
paxks to swelling ,it will help in regressing the swelling.
Additionally he needs antibiotics and analgesic
anti inflammatory drugs.
Hope I answered your question.