It could be viral, but it appears to me to be more bacterial. It would almost surely be bacterial if it were on one side only as fish do scrape against surfaces and the scrape will become infected with bacteria, which do cause redness and swelling, similar to a scraped knee or minor cut. To find almost the same size lesion on both sides at a similar location seems doubtful, but not impossible. In the cold water an infection will take forever to heal and may have been there for some time, and now that the fish is inside in warmer water it could go either of two ways, get better or get worse. I think I would wait and see before doing anything, but I would have on hand some antibiotics if it gets larger or redder. If it is viral, there is nothing that can be done but wait it out.
Zone 7 A/B
Keep your words sweet. You never know when you may have to eat them.
Richard