Red Bubbles at fin base?

I have a cory cat that recently developed what can only be described as some red bubbles at the base of his dorsal fin. His fins seem to be a bit frayed, but this very well could be do to his competing with other male corys in the aquarium to mate with the single female. While the fins are frayed they do not appear to have any growths or discoloration on them. He seems to be eating and moving just fine, like nothing is wrong. Any idea what this could be? Please let me know ASAP since the tank is full of young bristlenose that I don't want to be infected with any diseases!

Thanks.