Hello. Welcome to Healthcare Magic. I'm Dr. Christensen.
It isn't unusual for
lymph nodes near a
bee sting to swell. Lymph nodes react to any inflammatory process in the region they "survey," and once they become reactive they can remain swollen for several weeks.
Unfortunately, without an examination it isn't possible to tell if your son has developed an infection at the site of his sting. This, too, would trigger swelling in nearby lymph nodes. An infection, of course, would warrant an antibiotic prescription, which you can only get from your doctor.
It would be helpful if you could get a better look at the back of your son's head. If there's any
redness,
drainage, or warmth at the site of the sting, or if your son has a fever (even a
low-grade fever), these could be signs of infection and would indicate that a medical evaluation is needed. If you can't get a good look at the sting site, or if you're not certain this area isn't infected, I'd suggest you take your son to your doctor.
I hope that helps, and good luck!