Definition: Full thickness tissue loss

Full thickness tissue loss with exposed bone, tendon or muscle.

Slough or eschar may be present. Often includes undermining

and tunneling. The depth of a Category/ Grade IV pressure ulcer

varies by anatomical location. The bridge of the nose, ear,

occiput and malleolus do not have (adipose) subcutaneous

tissue and these ulcers can be shallow. Category/Grade IV

ulcers can extend into muscle and/or supporting structures (e.g.,

fascia, tendon or joint capsule) making osteomyelitis or osteitis

likely to occur. Exposed bone/muscle is visible or directly

palpable.

NPUAP/EPUAP Pressure Ulcer Classification System 2014