What term describes a thin dry or oily plate of epidermal flakes, such as dandruff?

The term that describes a thin dry or oily plate of epidermal flakes, such as dandruff, is "scale." Scales are formed from the shedding of skin cells and can be seen in various conditions affecting the skin, including seborrheic dermatitis, psoriasis, and dry skin. They are characterized by their flaky appearance and can vary in size and texture.

In contrast, a crust refers to a hardened layer of dried exudate that forms over a wound or lesion, usually containing blood, pus, or serum. A patch is a flat area of skin that differs in color or texture from the surrounding skin but does not have the flaky characteristics associated with scales. Lastly, a scab is a protective crust that forms over a wound during the healing process, primarily composed of blood and serum that dries and hardens. Each of these terms refers to specific types of skin lesions or conditions, but "scale" is the correct descriptor for flakes like those found in dandruff.