There is a type of Ich called "Black Ich" that is caused by a flatworm. Here is a link to more info on it.

http://www.petsforum.com/personal/tr.../blackich.html

The article recommends treating with a formalin or FW dip. I think Prazi Pro may also be a possible treatment as well. Check with Richard. He would be the best person to make a recommendation for treatment.