it could be your lungs or sinus. regardless, the source of your problem is your digestion and large intestines. yes, your sinus and lungs are connected to your large intestines. amazing right? you may not believe it, but it all up to you. how do i know? it's by listening to dr. bob marshall (see healthline.net). they have a radio program (see their website for radio station and time of broadcast in your area).
just like me, you may going back and forth to different doctor (md's, ent's, allergists, immunulogists) for long time and they won't be able to solve your problem PERMANENTLY, except controlling your sysmptoms.
improve your digestion and your problems will go away. call and consult with them