Which skin layer is affected by a first degree burn?

A first-degree burn primarily affects the epidermis, which is the outermost layer of the skin. This type of burn is characterized by redness, mild swelling, and pain, but it does not penetrate deeper layers like the dermis or subcutaneous fat. The epidermis is responsible for providing a barrier against environmental factors, and when it sustains a first-degree burn, it may be damaged, resulting in irritation and inflammation.

Understanding that the dermis, which lies beneath the epidermis, is not affected in a first-degree burn is key. The dermis contains more sensitive structures, such as nerves and blood vessels, which would show signs of damage in second-degree burns or greater. Hence, first-degree burns are generally more superficial and involve only the epidermis.