Which disease(s) starts with flashing/itchiness?

[Labora]

Which disease(s) starts with flashing/itchiness with no sign of ich?

 

[Jay Hemdal]

Flukes, copepods and even ich when the tomonts aren’t quite large enough to visualize. Sometimes, infrequent flashing is idiopathic and doesn’t have a disease associated with it; could be behavioral (clowns and wrasses) or it could be environmental (detritus in the water, getting stung by a coral).
Jay