Corydoras growth on top of nose

[Joey4151]

I included a few photos of my sterbai corydoras with a growth on the tip of his nose. It looks to be yellowish in color and has doubled in the last 3 weeks or so. It started growing 3 weeks ago.

He is eating, swimming in his group and behaving normal like he has in the last year.

Water parameter is:

ammonia 0
nitraite 0
nitrate 20

What is that growth?

 

[A201]

Looks like a viral blister to me. Eventually the blister should pop & the wound will likely heal.

 

[Joey4151]

Looks like a viral blister to me. Eventually the blister should pop & the wound will likely heal.

Hey, thanks for replying.

I think you are correct.
It grew to a bigger size and then it slowly went away. The whole time the corydoras acted if nothing was wrong. What ever it was; it is gone.