Dwarf Gourami Disease?

[trianglekitty]

I have a dwarf who has had ongoing issues with Ich despite multiple treatments of various types. Now his top fin is turning "dark" and peeling a little toward the tip. I'm not sure if this is a reaction to the various meds he's been on (Rid-Ich was the most recent), a reaction to the salt I just added to his water, or something else entirely. My worst fear is that this is the start of dwarf gourami disease.

Does this sound like dwarf gourami disease? He's still eating well and is active, though perhaps a little less active than is normal for him. His water parameters are normal.