School sore is a type of sore that is caused by environmental bacteria. They are usually treated with Antibacterial creams or oral ABs.

They are wildly contagious, (hence "school sores" as they can go around a school like wildfire) but like all bacteria he might have picked it up anywhere.

My tip for taking ABs - use a syringe (easy to measure the dose) then squirt it into his mouth near his cheek. Maybe use a lolly as a bribe once he has swallowed it?

Sorry don't have any experience with tongue tie and the ankles, I hope that all goes well!