Sick Bronze Corydoras

Help, i noticed one of my cory's has developed a whiteish patch on his side with a lump sticking out of it. it definately wasnt there a week ago when i did my last water change. so its developed quickly. I dont think ots white spot as i've had that with other fish before. Help as to what it may be and what i should do please

many thanks all

brad

Doesn't look fluffy at all, is it?

Looks like columnaris "saddleback disease" to me. Treat with a gram-negative bacterial med. or any thing specificaly made for it.

It looks like a bacterial infection. Treat with a bacterial medication, this should help improve his condition. Also how often do you perform water changes?