Chinchilla sneezing

My chin started squeezing his snout between the cage bars (0.5" spacing) and elsewhere today, and sneezing a lot every time he did this. Previously the sneezing would subside when he was taken away from the tight spaces, but now he just continues to sneeze periodically. I don't see any unusual discharges, unhealthy poop or other erratic behaviors. Suggestions?

Here's the little guy: http://ift.tt/2a5qIjF