Name of disease:Velvet
Type of disease:Parasite
Symptoms include:Flashing and scratching, thick slime coat, white-yellowish patches on the skin.
Just like Ich, Velvet will produce little swarmers of new parasites that will go all over the tank within a few days. Velvet mostly comes into the tank via not quarantined fish, so the best solution in preventing that parasite is either not to introduce new fish at all to a tank, or quarantine the fish and treating the fish accordingly, after searching for parasites with the microscope.
Treatment:Salt is not very effective, but QuickCure for 3 days, or any medication containing Formalin will do the trick. So does Copper, although Copper can be a bit harsh on the fish..
Medications: QuickCure, Maracyn, and medications with formalin