can post nasal drip cause a white coating on the back of the tongue? i brush and floss pretty regularly, but for a few months i've noticed a whitish coating on the back of my tongue. it doesn't look like thrush at all. sorry for the grossness, but mucus also collects at the back of my tongue. i have a long history of allergies and sinus issues but i've never really had a coating this prominent before. does anyone know what it is or how to clear it up?
i have no autoimmune diseases and i took metronidazole about a month ago, but like i said, i had this problem prior to the antibiotics so i don't think its thrush.