Final answer:
A pressure ulcer involving partial-thickness skin loss involving the epidermis and dermis, presenting as an abrasion or shallow crater, would be classified as Stage 2.
Step-by-step explanation:
The pressure ulcer described in the question, involving a partial-thickness skin loss involving the epidermis and dermis, presenting as an abrasion or shallow crater, would be classified as a Stage 2 pressure ulcer. Stage 2 pressure ulcers involve the skin layers beyond the epidermis and are characterized by the formation of a blister or shallow ulceration.