My 11 year old, for past year, has been sneezing and blowing his nose constantly most mornings and nights. We keep a very clean house and have no pets. It is becoming very frustrating, as hes always stuffy especially mornings/nights. No one else in our household is like this. He did have some allergy testing done and hes allergic to seasonal stuff, pets, some foods and dust mites. How can I figure out whats causing this daily? Is there another doctor or test I should consider? Thanks!