Aziz plz fill out the disease questionnaire so that there is a more info available to make determinations from. It's hard to see the wounds you are talking about in the pics you posted, but from the little you shared 2 hypothesis come to mind; the first is cross contamination from introducing either the rummy nose or the plecos...did you quarantine either before putting them in? Secondly, I have heard of plecos trying to feed off the slime coat of discus and injuring them...the wounds don't look very big, so maybe even discus pimples which appear d/t poor water quality & nitrates consistently >10.