Open comedones are?

• A. Whiteheads
• B. Blackheads caused by debris, oil, and dead skin cells
• C. Pustules
• D. Papules

Answer: (B)

Open comedones are a type of clogged pore in acne where the opening remains exposed to the surface. The blockage is formed by a mixture of sebum (oil) and dead skin cells. Because the pore stays open, the material at the surface is exposed to air, which causes the sebum to oxidize and darken, giving the familiar black appearance of a blackhead. This is a noninflammatory lesion, unlike pustules, which contain pus, or papules, which are raised and inflamed without pus. Whiteheads, in contrast, are closed comedones where the pore is blocked but not open to the air, so they stay pale.