Hardened sebum trapped in the follicle is known as a?

Hardened sebum trapped in the follicle is referred to as a comedone. This term specifically describes a type of acne lesion that occurs when hair follicles become clogged with oil and dead skin cells. When this blockage is open to the air, it is known as a blackhead, while a closed blockage results in a whitehead. The hardness of the sebum, due to oxidation and accumulation, leads to the formation of these comedones.

Understanding this concept is crucial for estheticians as it relates to the various forms of acne and skin conditions that they may encounter in clients. Recognizing the distinction between types of lesions, such as comedones versus cysts or papules, enables more effective treatment and care strategies for maintaining healthy skin.