Pressure ulcers are best defined as which of the following?

• A. A superficial skin abrasion from friction.
• B. Open wounds created by local necrosis of skin and underlying tissue due to pressure-induced ischemia.
• C. Red marks caused by shear forces.
• D. Full-thickness burns due to pressure.

Answer: (B)

Pressure ulcers develop when sustained pressure over a body area exceeds the capillary blood flow, causing ischemia and subsequent tissue necrosis. This process leads to tissue breakdown and an open wound that involves the skin and often deeper structures. That is why the correct definition describes an open wound created by local necrosis of skin and underlying tissue due to pressure-induced ischemia.

Frictive superficial abrasions are just surface damage from rubbing and don’t involve ischemic necrosis. Red marks from shear are blanching or non-necrotic erythema without tissue loss. Full-thickness burns from pressure imply thermal injury, not ischemic tissue death from pressure.