From Lost Fables Wiki
A fungal growth arising from lack of hygiene or contact with an infected host or fungal colony
The disease is extremely infectious, through direct contact with either the host or spores, released when a scale falls off or is scratched. In addition, at the end of its life, a colony will deflate, spreading spores for possibly hundreds of meters around.
Scaled beastfolk and other scaled creatures.
When first contracted, it is merely an itch. If left, it will progress into a sweet-smelling musk as it grows for several weeks. By the end of the first month, slight bluish fungal growth can be seen if closely inspected. As the itch gets worse, the host begins to experience greater and more draining fatigue. The itch will continue to get worse and spread, until it takes up about a square foot or so of scales in the second month of infection, and by this point the host typically lacks the energy to move at all. When it reaches a certain critical mass, again, about 2 square feet of growth, the fungus pulls itself away from its host in an agonizing several hours, and slowly crawls off to somewhere dark and damp to grow over and devour the section of scales, becoming a stationary fungal colony. The host usually does not survive the experience, and as the colony leaves, it tends to reinfect the fatigued host, who goes through the cycle again, assuming they live long enough, which they almost never do.
If left untreated, it will almost certainly kill.
An extremely hot bath and simple lye soap will take care of it if caught early. Later stages of the disease require the infected scales to be cut away, and the raw skin below scrubbed.