Greyscale

Greyscale is a disease hat can leave flesh stiff and dead and the skin cracked and flaking, mottled black and grey and stone-like to the touch.

Princess Shireen Baratheon has half of her face disfigured by the disease.

In the books
In the A Song of Ice and Fire novels, greyscale generally affects children, specially in cold damp climates. The victims are disfigured but could not be touched by the rarer mortal form of the affliction or the grey plague. The wildlings consider people who survive Greyscale unclean.