What is Acne?

Acne is a skin condition in which the pores of the skin become clogged with dead skin and sebum (oil that lubricates skin). Clogged pores can become infected causing whiteheads, blackheads, pimples and/or cysts that occur primarily on the face, neck, chest, and back.

Acne affects most teenagers to some extent. While not a life threatening condition, acne can be upsetting and disfiguring.

Types of Acne

When you read about acne, you come across words that may be confusing. For example, the words used to describe acne comedo, papule, pustule, and cyst are understandable only if you know each words definition. It also is helpful to have a photo that shows each type of condition.

Comedo

A comedo is a skin pore (opening) clogged with oil, dead cells from inside the pore, tiny hairs, and sometimes bacteria. When a comedo is open, it is commonly called a blackhead because the surface of the plug in the pore has a blackish appearance. A closed comedo, more commonly known as a whitehead, is a white bump on the skin that forms when a pore gets clogged and stays closed. Its appearance is that of a skin-colored or slightly red bump in the skin. The whitehead differs in color from the blackhead because the opening of the plugged pore to the skin's surface is closed or very narrow, in contrast to the larger opening of the blackhead.

	Papule (also called a pimple) A papule is a small, solid irritation slightly raised above the surface of the skin. A group of very small papules and comedones may be almost invisible but have a sandpaper feel to the touch. Photo A. shows papules and comedones on the face of an acne patient.
	Pustule(also called a pimple) A pustule is a small red infection that forms if a clogged pore bursts and lets the oil, bacteria, and dead skin cells make their way under the skin. Photo B. shows pustules, papules and comedones on the face of an acne patient.
	Cyst A cyst is an infection similar to a pustule except much larger. It is a sac-like structure containing white blood cells, dead cells, and bacteria. A cyst can form if a clogged pore bursts very deep in the skin. Because cysts can become inflamed and extend into deeper layers of the skin, they may be very painful and can result in scarring. Photos C. and D. show cystic acne.