What is the term for dead skin cells that accumulate on the surface, such as dandruff?

The term that refers to dead skin cells that accumulate on the surface, including conditions like dandruff, is "scale." Scales are formed when the skin produces excess keratin—a protein that makes up our skin, hair, and nails—leading to visible flakes. This accumulation can result from various conditions, including dry skin or other skin disorders.

In contrast, the other terms refer to different skin manifestations. "Fissure" denotes a deep crack or split in the skin, while "ulcer" refers to an open sore that results from the loss of the skin's outer layer, and "crust" typically describes a dried over-formation of bodily fluids (like pus or blood) that hardens on the skin's surface. Understanding these distinctions helps in both recognizing and treating various skin conditions appropriately.