Define comedones.

Comedones are indeed commonly known as blackheads and whiteheads. They represent a type of non-inflammatory acne lesion that forms when hair follicles become clogged with sebum (oil) and dead skin cells. Blackheads are open comedones where the clogged material is exposed to air, causing it to oxidize and turn dark. Whiteheads, on the other hand, are closed comedones that remain beneath the surface of the skin, giving them a white appearance.

Understanding this definition is crucial for recognizing types of acne and understanding skin health. While inflammatory acne lesions refer to more severe forms of acne that include pustules, papules, nodules, and cysts, comedones themselves are not inflammatory. Additionally, severe forms of eczema relate to a different group of skin conditions marked by inflammation, irritation, and itchiness, which is unrelated to the definition of comedones. Therefore, the identification of comedones as blackheads and whiteheads is an essential distinction in dermatology and skin care practices.