Postnasal drip is drainage from the nose and sinuses dripping down the back of the throat. There could be several reasons for this drainage. One reason is an allergy. A second reason is a non-allergic, non-infectious inflammation in the sinuses that can linger after a cold. A third reason is chronic sinusitis. Postnasal drip can effect your voice, especially your singing voice, as a result of irritation of the throat and vocal cords. You may experience the postnasal drip as a constant feeling of mucus at the back of your throat. Typically this is worse at night when you lay down to sleep. Generally this irritation feels the worst when you wake up and gets better as the day goes on. The mucus may "sit" there, especially when it is thick.
The fat content in dairy products can thicken mucus. Generally eating dairy products with less fat content is helpful. Drinking plenty of water will help to thin the mucus so that it moves more easily. As long as you are not on a fluid restriction you should be drinking 6 to 8 8-ounce glasses of non-caffeine non-alcoholic fluid daily. So drinking 64 ounces of water each day is great! Clearing your throat can irritate your vocal cords and effect your voice. When you feel the need to clear your throat sip some water to clear the mucus.
An antihistamine can dry up the postnasal drip. However, as you have noted, it may make the mucus thicker and more difficult to move. So it would be best to follow the recommendation from your ENT to avoid antihistamines. A decongestant like Sudafed
Something you said triggered a thought. You may not have PND at all and maybe have LPR (Reflux of the Larynx). This is common with singers. Go on google and search LPR reflux. Your symptoms sound very similar. Did your ENT do a scope??
Good luck!
Time to see a GOOD allergist to help you. Your doc has to help you figure out WHY you have the post nasal drip--what triggers you. This can often been done by testing--blood test (RAST) or skin testing. Once you know what you're sensitive to, you can try reducing your exposure to these "triggers" and reduce your post nasal drip.
The allergist will help you develop a plan that will help get your allergies udner control as well--avoidance and medication and even possibly allergy shots.
Here's a page with info about nasal saline wash--it REALLY helps many folks:
http://nationaljewish.org/medfacts/nasal.html
Here are other sites you may also find useful:
http://nationaljewish.org/understanding/allergy.html
http://nationaljewish.org/medfacts/allergic_rhinitis.html
http://nationaljewish.org/medfacts/mites.html
Good luck--hope this helps.
For me, I have tried all the antihistimines & decongestants & found that the ONE that works for me is Zyrtec. Others have found different ones and/or combos work for them. I also find that Flonase nasal steroid works great for me as well. The nasal wash helps when I need it, but I don't use it daily though some folks do & find it extremely helpful.
Starion