For several months now, I have experienced excessive mucus drip in the back of my throat, yet cannot expectorate it. My throat is sore and the middle of my tongue has a raised ridge that appears to be white. Also, I experience some difficulty swallowing when the mucus is flowing. I have a history of allergies, but this is new. I also have asthma that is under control. Over the counter medications for allergies have not given me relief. I have considered food allergies and have limited the mucus producing food products such as dairy products, but still daily I am swallowing mucus and cannot cough it out. Please advise. Thank you.