Google how gluten intolerance can cause post nasal drip. I also thought my allergies were coming back (got shots for 10 yrs, every week about 12 yrs ago). For the past year or so my post nasal drip has gotten worse (daily, monthly, any season). Allergy meds, flonase, etc do nothing. Now I find there’s a connection to gluten. I also have other gluten intolerance symptoms that I have always attributed to IBS. I get allergy tested next week just to make sure. The day after the test, I will be going gluten free. I have noticed that my post nasal drip is horrible after I eat processed foods (breads, pizza, etc).
Virus anywhere in the upper respiratory tract can affect you sense of smell: the olfactory sensory nerves are very sensitive. Saline nasal rinses are unlikely the cause of “spreading virus from your ear to your olfactory area,” but I suppose it’s possible. I have occasionally seen patients (or in my own personal experience) where a sinus infection seems to spread to an ear infection. That MAY have been related to saline rinse moving through an infected area (nasal passages) into the throat (where Eustachian tubes travel to the middle ear), but again: that ‘spread’ of infection may have occurred even if saline rinses were not being done.