Could Sore Throat And Fever Be The Reason For Swelling In Forehead?

Hi, my 9 year old son was sick at school yesterday with headache, fever and lymp nodes swollen on both sides of his neck. He stayed home today and was feeling alot better and was very hungry all day even was playing with our dog. This evening the fever came back and his neck is hurting and his forehead is swollen. The lymp nodes, fever and sore neck are things that seem kinda normal for a cold or sore throat, but the swelling of his forehead has me really concerned. Could this be caused by the fever? Could it be caused by whatever the cold or illness is? Or could it be something serious that I may need to take him to the hospital.