Help: medicate or watch and wait?

[linksys]

The pic shows the underside of my pleco. The sore started out as more of a white spot, and now shows some red....is this a heater burn or hmmm fungus??

Also, what's the small pimple looking thing on his belly?

Overall the pleco is eating and pretty active, so I'm not sure if I should wait and watch, or medicate. I do have prazipro on hand, and was planning on giving it a try.

I appreciate any and all help here!

 

[Warborg]

First one looks like a scratch. Medicating will help.

Second one is where he poops?

 

[shookONES]

I wouldn't get too invasive with treatment. A little aquarium salt and elevated oxygen levels will do wonders.