Blue dot on zebra danio's mouth?

[Fish.Noob]

Hey guys, there's a blue dot on the lower lip of one of my dad's zebra danio's... What should we do? Picture is attached below:

 

[Fish.Noob]

Here's a better picture

 

[V227]

Maybe a minor outbreak of Lymphocystis, more or less a fish cold sore. If the growth begins to turn white & spread around the mouth, then likely the problem is bacterial in nature.