Thanks for posting on HCM
From your description it is obvious that your child is presenting with an infection which could be viral or bacteria. With your presentation it is more likely bacteria which normally should be resolved in a few days or antiviral medication
could be administerd ( usually not necessary). If your kid can obey simply instructions such as being able to wash his mouth and throw out the waster, then i'll suggest mouth wash solutions with antiseptic properties such as eludril or hextril.
Since your doctor has run a strep test
, it does not mean that other bacteria such as staph can not be involved.
So if after a few days, your child still presents with the affection, blood work will be advised to find out if bacteria infection.
Hope this helps