Thanks for the link.
I didn't notice any wounds/rubs on the nose before it got to that point. I noticed this shortly after a time when she got scared and jump all around her transport terrarium like crazy and hit her head on the lid several times. It's a standard plastic terrarium with a plastic grid on top. I've since added a piece of fabric (with air holes for additional air exchange) that I'll stretch under the top the next time I need it.
I'm wondering if it could be a wound that got infected, or a broken nose. Judging by human standards, it's been this way (with no noticeable change) too long for it to be regular hit-yourself-on-something swelling.