Which pressure ulcer stage represents an ulcer that has a partial thickness defect in the skin?

A Stage II pressure ulcer is characterized by a partial thickness loss of skin, which includes the epidermis and possibly the dermis. This stage presents as a shallow, open ulcer with a reddish-pink wound bed and may also appear as an intact or ruptured blister. This partial thickness defect means that while the wound extends through the epidermis and into the dermis, it does not penetrate through the full thickness of the skin, making it different from Stage III and Stage IV ulcers, which involve deeper tissue loss.

In contrast, Stage I ulcers do not exhibit any actual break in the skin, instead presenting as non-blanchable redness over a bony prominence. Stage III ulcers involve full thickness skin loss where subcutaneous fat may be visible, and Stage IV ulcers involve deeper structures such as muscle, bone, or tendons. Thus, a partial thickness defect in the skin corresponds specifically to the characteristics defined for Stage II.