The degree of burn that only affects the outer layer of the skin is known as a 1st-degree burn. Here's why:
1. First-degree burns, also called superficial burns, only damage the top layer of skin, which is the epidermis.
2. These burns are characterized by redness, minor swelling, and pain, but they usually heal within a few days without causing blistering or scarring.
3. In contrast, second-degree burns (partial-thickness burns) affect both the outer layer (epidermis) and the layer underneath (dermis), leading to blistering, more severe pain, and the potential for scarring.
Therefore, the correct answer to the question is a 1st-degree burn.
