I used to suffer from this problem starting last November. When it got worse and I started losing my voice, my GI suggested I should see an ENT doctor. I did. He performed a sinus CT and throat samples and all came out negative. The ENT doc said that this all was caused by my reflux and that I had to get back to my GI to treat it. I'm on Nasonex too and Areius (losartadine) every night and things started to become better. Make sure to suppress reflux before you sleep so that it does not go back. I take Gaviscon Advance.
Take care :)
GERD, gastroduodenitis, ileocolitis, chronic proctitis and persistent mouth ulcers and fissures
Current meds: Pentasa sachets 4g, Entocort 4.5 mg, Nexium 40 x2, Ensure, Calcium and magnesium supplements, Imuran 150mg, Zantac 300mg (not any more), Gaviscon 1x4
Pred 40 mg from Oct. 2010 till Jan.2012