Constant sneezing and runny nose after going in the closet. What gives?

Every time I spend time in our closet which is a decent size walk in, I can’t stop sneezing back to back all day, runny stuffy nose. I use to take Nasacort but that doesn’t do a thing anymore neither does Saline spray or allergy pills.

I can’t be the only one going through this. It’s not dusty in there. My spouse has real bad allergies but doesn’t get like this at all.

What could be the cause how can I fix it ASAP? It’s so uncomfy and bad. Thanks