What is the outer layer of skin called?

The outer layer of skin is called the epidermis.

The epidermis is the skin’s outermost major layer, sitting above the dermis and hypodermis. It forms a protective, waterproofing barrier that helps keep pathogens and harmful chemicals out while reducing the loss of water from the body. Unlike the dermis, the epidermis has no blood vessels of its own.

Its main cells are keratinocytes, which produce keratin, a tough protein that helps strengthen the skin. The epidermis also contains melanocytes, which produce melanin, plus Langerhans and Merkel cells. New cells form in the basal layer and gradually move upward as they mature, fill with keratin, die, and are shed from the surface.

A common mix-up is confusing the epidermis with the stratum corneum. The stratum corneum is the epidermis’s outermost sublayer, not the name for the entire outer skin layer. The epidermis usually has four strata, or five in the thicker skin of the palms and soles, where the stratum lucidum is present.