Eschar

Eschar, from the Greek *eschára* (hearth, burn site; French *escarre*), refers to a firmly adherent, dry, coarse, usually dark brown to black plaque of necrotic, often mummified tissue.

An eschar develops as a result of localized tissue necrosis, such as in cases of ischemia and occlusive vasculopathies, pressure injuries, burns, chemical burns, or severe infections. Once the eschar is fully demarcated, it may slough off spontaneously, or surgical debridement may be necessary.

Definition: Unlike the superficial crust (crusta), which consists of dried serum, blood, pus, and cellular debris, the eschar comprises necrotic tissue and therefore usually extends deeper.

1. Dunn C et al. (2019) The rash that leads to eschar formation. Clin Dermatol 37:99-108.
2. Hu Z et al. (2025) Neglected Eschar. J Emerg Med 75:227–228.