White spot on Corydora fin

[sliderfish]

I recently noticed a white spot on the fin of one of my Emerald Corys yesterday. The spot is on his dorsal fin near the base and seems to be a growth of some kind. Doesn't look like Ick, but IDK for sure. No other fish has a problem.

I did just lose a Clown Loach in the tank about three days ago. He ripped his tail trying to free himself after getting stuck in a piece of decor and died the next day of his injuries. Not sure if the two incidents are connected.

Any ideas of what the spot may be caused by and how to treat it?