eschar

As nouns the difference between fascia and eschar

is that fascia is a wide band of material covering the ends of roof rafters, sometimes supporting a gutter in steep-slope roofing, but typically it is a border or trim in low-slope roofing while eschar is a dry, dark scab or scar, especially as a result of burning.

As an adjective necrotic

is (pathology) of or pertaining to necrosis, particularly of tissue.

As a noun eschar is

a dry, dark scab or scar, especially as a result of burning.

As nouns the difference between eschar and necrosis

is that eschar is a dry, dark scab or scar, especially as a result of burning while necrosis is (pathology) the localized death of cells or tissues through injury, disease, or the interruption of blood supply.

As nouns the difference between eschar and slough

is that eschar is a dry, dark scab or scar, especially as a result of burning while slough is the skin shed by a snake or other reptile.

As a verb slough is

to shed (skin).

As a proper noun Slough is

a town in east Berkshire, and formerly in Buckinghamshire, close to Heathrow Airport.