Hello, rock,
Sometimes there is a problem with the sinuses and nasal passageways draining due to a blockage or malfunction of the cranial bones, jaw and/or facial bones.
It may benefit your son to see a good chiropractor or therapist who specializes in cranial work..cranio-sacral therapy or the like. It would be good if the chiropractor also has knowledge of kinesiology, or muscle-testing, as well...that way, he can evaluate the results of his work right there in the office.
To find such a therapist, contact:
Cranial Academy
3500 Depaw Boulevard
Indianapolis, IN 46268
(317) 879-0713
Also there are small nasal irrigation machines available that can be used to clear out the nasal passages and sinuses. I like the Grossan Hydro-Pulse system...you can get the whole system and the salts used for irrigation for around $90. There are cheaper systems as well that can be obtained at various department stores.
Good luck to you and I hope this is helpful.