Illness/Sickness: Swollen red patch on axolotls back

[EllieMC2]

My axolotl has developed a slightly swollen red area on her back. I have uploaded 2 photos showing this. One of my other axolotls developed a fungus (tank mate) so they have both been having daily salt baths with aquarium salt at 2 teaspoons per litre for 10mins to treat the fungus. This axolotl did not have the fungus, they are both eating well and show no behavioural changes. Is the swelling normal? Or is this likely stress from the salt baths? Grateful for any help. Thank you.

 

[Hayleyy]

I'm not too sure about this. It kind of looks like a wound but I don't imagine that could be caused by the salt baths, but may be getting irritated by it? I wouldn't use salt baths for this axie since it didn't have any fungus. Maybe look into tea baths for this one.