Which term describes a crack in the skin that penetrates the epidermis?

A fissure is defined as a long, narrow crack or opening in the skin that extends into the epidermis, the outermost layer of the skin. Fissures can occur in various areas, particularly in sites where the skin is subject to tension or is often exposed to moisture, leading to dryness and cracking.

In the context of skin conditions, identifying a fissure is important because it can indicate underlying issues such as dryness, irritation, or more severe dermatological conditions that compromise the skin's integrity. Unlike a pustule, which is a small blister containing pus, or an ulcer, which involves a deeper loss of tissue and may affect the dermis and underlying structures, a fissure is superficial, limited to the epidermis and potentially the upper layers of the dermis. A nodule, on the other hand, is a solid mass of tissue that is larger and does not describe a crack or opening. Understanding this terminology is crucial in pathophysiology and dermatology for the accurate identification and treatment of skin issues.