What Causes Loss Of Sense Of Smell In Only One Nostril?

I know this may sound strange, but I can only smell out of one nostril. I have tried to find out what this could be by searching online and speaking with my physician and I have had no help.

What could this be? I was thinking anosmia, but I have found that it is very rare to lose smell in one notril and not both. Hmmm....??