J.C.
That happens to my daughter when she is having upper respiratory issues, but they quickly go away. I have mentioned it to the pediatrician and was told it was a sign of an infection, but it shouldn't last for a long period. Regardless of his size, those lymphnodes shouldn't hurt to the touch. I would probably see an ENT.
I know I would get them a lot years ago because I had many ear infections, but once I started taking liquid silver, I didn't have any more problems.