Eschar is a collection of dead tissue that forms a covering over wounds with significant damage, like deep burns or certain ulcers. This devitalized tissue is typically black or dark brown with a thick, leathery texture. In some cases, the texture can be soft or boggy, which may indicate an underlying infection.
Causes and Formation of Eschar
The development of eschar begins with tissue necrosis (tissue death), which occurs when an insufficient blood supply deprives tissues of oxygen and nutrients. The dead tissue then dries out and hardens, forming the characteristic leathery covering of eschar. Third-degree burns are a common cause, where intense heat destroys skin tissue.
Pressure ulcers, also known as bedsores, develop from prolonged pressure on the skin that cuts off circulation. Other causes include gangrene, certain venomous bites, and infections like cutaneous anthrax.
Distinguishing Eschar from a Scab
Eschar is often confused with a scab, but they are fundamentally different in composition and function. A scab is a normal part of the body’s healing process for superficial injuries. It is primarily made of dried blood, platelets, and serum that form a protective crust, shielding the new, healthy tissue forming underneath.
In contrast, while a scab protects a healing wound, eschar acts as a barrier that prevents the wound from closing and new tissue from growing. The presence of eschar signifies a much more significant injury.
Medical Evaluation and Treatment
The presence of eschar necessitates a medical evaluation because it can hide underlying infections and physically obstruct the healing process. A healthcare professional must assess the wound to determine the extent of tissue damage and check for concealed infection.
The primary treatment for eschar is its removal, a procedure known as debridement, which allows the healthy tissue underneath to begin healing. Surgical or sharp debridement involves a healthcare provider using instruments like a scalpel to cut away the eschar. Another method is enzymatic debridement, where prescribed ointments containing enzymes are applied to break down the necrotic tissue. Autolytic debridement uses the body’s own enzymes to dissolve the dead tissue, facilitated by keeping the wound moist with specific dressings. A medical professional will determine the most appropriate approach.