Our eldest is prone to tonsillitis and can't take the good AB's. Our GP never messes around with it particularly when he has spiked a high fever. Our temp usually breaks withing 24 hours after the initial dose of AB's, if he still isnt finding any relief after that a check up certainly wont hurt. Because of the type of SB we use we usually have to go back in a week to make sure its helping anyway. Make sure you keep the fluids up to him where you can.