What type of skin lesion is characterized by a crack or groove on a surface?

A fissure is characterized by a crack or groove on a surface of the skin. This type of skin lesion typically occurs in areas where the skin is subject to repeated pressure or movement, leading to a split or fissure in the epidermis. Fissures can develop due to dryness, inflammation, or infections and may occur in various locations on the body, such as the hands or feet.

In contrast, a pustule is a small, inflamed elevation on the skin that contains pus. An exudate refers to fluid that leaks out of blood vessels into nearby tissues during the inflammatory process, which is not a physical lesion but more of a result of tissue injury or infection. Keratosis involves thickening of the skin, typically seen in conditions like seborrheic keratosis, but it does not describe a crack or groove specifically. Therefore, the term that accurately captures the description of a crack or groove is fissure.