Your doctor may need to remove the eschar or slough to determine the full extent of the ulcer. Further imaging or surgical evaluation of the area may be required. Symptoms.

Eschar: thick leathery black or brown devitalized tissue. It can be loose or firmly adherent, hard, soft, dry or wet. It reflects deep damage to tissues and is more severe than slough.

Eschar is dead tissue that falls from healthy skin. ... Stage 4: The most serious wound type, a stage 4 wound will likely contain some slough and be deep down in the skin.