What is xerosis?

Our staff is having difficulty with the definitions of tissue types seen in pressure ulcers. Can you help?

There are four basic types of skin tissue seen in pressure ulcers: slough, eschar, granulation, and epithelial tissue.  

Slough: soft moist avascular, devitalized (dead) tissue. It may be white, yellow, tan, gray or green, and it may be loose or firmly adherent. Slough may be seen in clumps, scattered, or completely covering a wound base. Its presence indicates tissue injury of stage III or higher pressure ulcers. Slough will never be present in a stage II ulcer.

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. To distinguish between a scab and eschar, remember that a scab is a collection of dried blood cells and serum and sits on top of the skin surface. Eschar is a collection of dead tissue within the wound that is flush with skin surface.

Granulation: beefy deep red irregular surface. It can have a puffy or mounded bubbly appearance. It replaces necrotic tissue in the wound as it begins to heal from the bottom up. It is seen only in stage III or greater pressure ulcers.

Epithelial: deep pink to pearly pink. The outermost layer of our skin is composed of epithelial cells. As wounds heal, epithelial cells regenerate across the wound surface from the edges to close the wound. Epithelial is seen in stage II or greater pressure ulcers.