There seems to be some confusion surrounding the definition of Scab and Eschar. I would like to clarify these terms for those who are unsure, as they both have different and distinctive meanings, which are not interchangeable.
Crust (scab): Made up of dried blood and serum and other dried exudate. 1-10
NOTE: No longer called a scab by wound care professionals. Crust is the correct term and
has been for many years, as it’s a more accurate description.
Eschar: Devitalized tissue, can be loose or firmly adherent, hard or soft, dry or wet.1-10
NOTE: Dry Eschar was originally used to describe devitalized tissue that appears in burns. In
cutaneous wound healing this term indicates the presence of dry necrotic tissue or Dry Gangrene.
It is important to understand the difference between Crust and Eschar, because the difference is great. One is made up of dried exudate and the other devitalized tissue. Devitalized tissue is a result of some level of ischemia.
Crust, on the other hand, always has a composition of dried blood, serum and dried exudate. On an established patient, if crust is removed and there is no wound, one cannot charge for a debridement because of the lack of a wound. In such cases the patient would have an outcome of healed, on a new patient; this would lead to the patient being discharged as a consult only, providing this was the only wound.
On the other end of the spectrum, when a patient presents with dry eschar, devitalized tissue which is also known as dry gangrene, we should always follow our wound care guidelines. Not following our guidelines may place the patient at risk. Under our guidelines for stable dry eschar (dry gangrene), as blood flow in the tissue under the eschar is poor and the wound is susceptible to infection. The eschar acts as a natural barrier to infection by keeping the bacteria from entering the wound. Our guidelines states “Do not debride stable, dry, black, non tender, non fluctuant, non erythematous and non suppurative eschars until perfusion status is determined...delay until perfusion optimized unless, soft, fluctuant eschar present which should be unroofed for drainage and culture.”
References:
1. Baranoski S. & Ayello EA. (2012). Wound care essentials: practice principles. (3rd Ed.). Philadelphia: Lippincott Williams & Wilkins.
2. Bryant RA, & Nix DP. (Eds.) (2012). Acute & chronic wounds: current management concepts. (4th Ed.). St. Louis: Mosby.
3. Cohen IK, Diegelmann RF, & Lindbald WJ. (1992). Wound healing: biochemical & clinical aspects. Philadelphia: W.B. Saunders Company.
4. Davis JS, & Bales MG. (1999). Understanding wound healing and principles of wound management. Brockton: Western Schools.
5. Goodheart HP. (2009). Goodheart’s: photoguide to common skin disorders. (3rd Ed.). Philadelphia: Lippincott Williams & Wilkins.
6. Kloth LC, & McCulloch JM. (Eds.) (2002). Wound healing: alternatives in management. (3rd Ed.). Philadelphia: F.A. Davis Company.
7. McCulloch JM, & Kloth LC. (2010). Wound Healing: evidence-based management. (4th Ed.). Philadelphia: F.A. Davis Company.
8. Myers BA. (2004) Wound management: principles and practice. Upper Saddle River: Prentice Hall.
9. Shai A, & Maibach HI. (2005). Wound healing and ulcers of the skin: diagnosis and therapy-the practical approach. Heidelberg: Springer.
10. Strauss MB, Aksenov IV, & Miller SS. (2010). Masterminding wounds. Flagstaff: Best Publishing.
11. Sussman C, & Bates-Jensen B. (2012). Wound care: a collaborative practice manual for health professionals. (4th Ed.). Philadelphia: Lippincott Williams & Wilkins.