Hopefully someone can give me some advice based on their own experiences, google is coming up with a lot of different advice! One of my lampeye has a strange white growth on its head - it actually looks like a bit of food at first glance (it isn't). He is feeding and swimming ok and no other fish in my aquarium seem troubled. There seems to be a number of different infections out there but each one requires different treatments. I would take a picture but these fish are small and quick - I can't get the focus needed to illustrate. All I can emphasise is the growth is not smooth and certainly not square in size, it appears to have a hollow in the middle (hard to see as, like I was saying, the fish is so small and fast).