Acne Cyst Described

Non-inflammatory acne

Closed comedo:

If the plugged follicle stays below the surface of the skin, the lesion is called a closed comedo. This usually appears on the skin as small, whitish bumps known as whiteheads.

Open comedo :

If the plug enlarges and pushes through the surface of the skin, the lesion is called an open comedo. The dark appearance of the plug is not due to dirt, but due to the buildup of melanin, the pigmentation element of the skin known as blackheads.

Inflammatory acne

Papule:

A small, firm pink bump. The papules are tender in nature and are often considered an intermediary step between non-inflammatory and clearly inflammatory lesions.

Pustule: 

Small round lesions that are inflamed and contain visible pus, which appear red at the base with a yellowish or whitish center. Pustules do not contain a large amount of bacteria. The inflammation is caused by chemical irritation from sebum components such as fatty free acids. 

Cyst: 

These are large pus-filled lesions that are usually present deep within the skin. The cysts are very painful lesions, as they are inflamed. Cysts form as a result of the contents of a comedo spilling over the surrounding skin and due to the response of the local immune system in producing pus. The cysts often leave deep scars. 

Acne conglobata: 

A rare but serious form of inflammatory acne that develops primarily on the back, buttocks, and chest, there may be severe bacterial infection.