Hi..
Welcome back..
I have gone through your query and can understand your concerns..
As per your complain sore and red throat along with sore mouth and gums that seems to be due to Gingivostomatits seems to be due to Viral infection..
In case if it is a Viral infection antibiotics will not be able to resolve it as they can fight only bacterial infection..
But for confirmation you need to consult an
ENT Specialist and get evaluated and a thorough clinical evaluation and investigations like throat swab culture can help in diagnosis and treatment can be done accordingly..
In case if it is due to Viral infection it will resolve once the virus will completes its cycle in human body..
As of now you can give supportive treatment like continue giving
Acetaminophen or
Tylenol or Calpol along with Nurofen and along with it you can apply numbing gel containing Lignocaine over the ulcers and gums.
Do cool compresses over the gums.
Make him do warm saline gargles..
Clean the teeth with soft toothbrush to avoid further irritation and bleeding..
Avoid spicy and hard foods..
The Physician can also advise
antiviral medication like
Acyclovir..
Any further questions are welcome.
Regards.