Which stage pressure ulcer would require the nurse to measure the extent of undermining?

Stage III

(a) There is no Stage 0 in the classification system for staging pressure ulcers. (b) The skin is still intact and there is no undermining in a Stage I pressure ulcer. (c) Tissue damage is superficial and there is no undermining in a Stage II pressure ulcer. (d) IN a Stage III pressure ulcer there is full thickness skin loss involving damage to subcutaneous tissue that may not be undermining, which is tissue destruction underneath intact skin along wound margins.