Princess Shireen Baratheon caught greyscale as an infant and survived, but the ordeal left half of her face disfigured by the disease.
In the books
In the A Song of Ice and Fire novels, greyscale generally affects children, especially 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.
Greyscale isn't the same thing as leprosy, as the effects are quite different. Still, the greyscale disease is dreaded in Westeros and Essos much as leprosy was in the real-life Middle Ages. A large area around the ruins of Chroyane in the Free Cities is even used as a large-scale colony for those who have contracted greyscale.
- Greyscale at A Wiki of Ice and Fire (spoilers from the books)