Platy Losing Scales

[mmw]

Ive got 5 platties and one betta in a 10 gal aquarium. All of the fish are ok except a yellow platy. It has lost all of the scales on the top of its head and starting to lose them on its back. The top fin seems to have disappeared as well as the bottom fin. Im new to the whole fish thing and the levels (pH, nitrate,etc are ok) What does this fish have, will it spread to the other fish and how do I treat this? Any help would be nice.

 

[WILDER]

Can you post your water stats please in ammonia, nitrite, nitrate, and ph.
Are any fish flicking and rubbing.
Any excess slime on the gills or body of the fish.
Does it look like the skin is peeling away.