Have you called the doctor back?
My children are experiencing allergy symptoms (runny nose) right now. I don't recognize the swollen lymph nodes (Maybe someone else has seen that in allergies?) & leg pain (this might be unrelated - growing pain?).
If you feel he's got an infection (is he feverish?), you might try this. It works for us.
When my children are sick, I give them tincture of echinacea root. I love it because it nourishes their bodies and encourages them to fight the infection.
From Susan Weed's book (herbalist) - It can clear up infections like blood poisoning, strep, staph infections and pneumonia. It's works as a preventative AND curative.
I use about 8 drops in water 2x/day for a week. Usually there is some change withing 48 hours.
You can get Echinacea from Chakra 4 Cafe over at the Town and Country shopping center on 20th Street and Camelback. I would talk to the owner, Kita, as well.
This is not intended to be a substitute for medical advice from your doctor. It's just what our family is comfortable using and has found to work in case of infection.
Hope he feels better!
M.