What is the term used for a crack in the skin?

A crack in the skin is referred to as a fissure. This term specifically describes a linear break or split in the skin that can occur due to various factors, including dryness, injury, or certain skin conditions. Fissures can be painful and may lead to more serious issues if not properly treated, emphasizing the importance of understanding this terminology for nail technicians, as they often deal with skin care and conditions related to the hands and feet.

In contrast, a callus is a thickened area of skin often developed due to friction or pressure, a nodule is a small swelling or lump, and keratin is a protein that makes up the structure of hair, nails, and the outer layer of skin. While these terms relate to skin and nail care, they do not describe a crack in the skin, which is why fissure is the accurate choice in this context.