Pharyngitis and tonsillitis are common causes. Usually this starts as a viral infection in which antibiotics is not necessary. If the sorethroat worsens, and phlegm develops, a course of antibiotics is helpful.
Tonsillitis is often associated with high fever in a child. If this is happening regularly, then a visit to the ENT doctor would be helpful.
The best time to bring your child to the ENT doctor is when your child is having the acute infection as this would allow a more accurate assessment.
If in doubt call our staff for advice.