Silent GERD is only one possibility.
But some research has discovered that chronic sinus problems are often due to a fungal infection in the sinuses. Try Xlear sinus rinse (follow the label directions), and use a neti pot with saline to rinse your sinuses several times a day.
If the sinus rinses don't help, does taking an antihistamine like Benadryl or Zyrtec help?
And if those don't help, maybe taking Tagamet or Zantac might help - even if you don't have acid reflux, these meds block a different type of histamine that sometimes can contribute to allergy type symptoms.
Chronic Lyme, Bart., Gluten & Sulfite Sensitivity, Many Food/Inhalant/Medication/Chemical Allergies & Intolerances, Asthma, Gut dysmotility & non-specific inflammation, Lupus, Osteoporosis, etc.; G-Tube
Meds: Flagyl, Domperidone, Zofran, Claritin, Andrographis & other herbs, homeopathy, supplements, etc.