My son has gotten it twice. It only happens when he is around his cousins who all are enrolled in daycare. My doc explained it is very common among kids in daycare or school. It can be very painful. My niece also had it and was admitted to the hospital b/c she couldn't drink b/c of the pain. I just kept on top of the Tylenol to help with the pain until it went away. My son never really got a fever, just cried from the pain of the sore mouth and throat.