A comedo is a clogged hair follicle (pore) in the skin. Keratin (skin debris) combines with oil to block the follicle. A comedo can be open (blackhead) or closed by skin (whitehead), and occur with or without acne.
What is the cause of comedones?
A comedo is formed by the debris blocking the sebaceous duct and hair follicle. It is now known that comedones also involve inflammation (see causes of acne). The development of comedones may involve the following factors: Excessive activity of the male sex hormone 5-testosterone (DHT) within skin cells.
What is a Comedone?
Comedones are another term for whiteheads and blackheads. Blackheads are referred to as open comedones, and whiteheads are called closed comedones. Comedones arise when pores become blocked with an oily substance called sebum ï¿½ a sticky substance produced by the sebaceous glands in the skin.
What is a solar comedones?
Solar or senile comedones arise on the face of the middle-aged and elderly. They affect areas that have been exposed to sunlight over a long period of time, particularly the cheeks, which may become yellow and leathery (solar elastosis). The comedones may be open (blackheads) or closed (whiteheads).