Possible parasite

Hi guys,

I'm desperately hoping someone can help me. My fish seem to have some sort of parasite. The affected fish is an Emperor Tetra and his body and fins have what look like pimples or warts on them. They stick out, giving him a bumpy look, like small swellings.
It's definitely not white spot or velvet.
It's hard to go describe so I will try and get a picture as soon as my camera batteries have charged.

At the moment there is one Emperor Tetra who definitely has it and a Cardinal who possibly has it.
The tank has Discus in it, so I definitely don't want them to get infected. Trouble is that it is a planted tank and so quite to catch the infected guys!

If anyone has any suggestions as to what it could be, I would be very grateful for your help. I can't find anything resembling it online

Thanks,
Gordon

 

Sorry - to add to this, the fish doesn't seem to be affected much by whatever this thing is. He's had for a few days now but eats normally and is still very active.

 

Does it look as though the body is swelling under the scales or does it look like it is on top of the scales?

 

Swelling under the scales, definitely. The biggest swelling looks as if some of his flesh has broken through the scales.