Cystic acne, which is also known as nodulo-cystic acne, is a very severe form of acne wherein a person develops acne in the form of small cysts. Acne cysts are not really cysts because they are not abnormal dilations of skin structure; instead, they are nodules of inflammation. Although this type of acne is not uncommon, it is much rarer than other types of acne.
Just like other kinds of Acne, cystic acne is caused by an excess buildup of sebum in the pore and, contrary to the popular myth, it is not caused or affected by the quality of hygiene maintained by the person.
Cystic acne usually affects the face, chest, back, shoulders, and sometimes, upper arms also. These cysts are usually filled with a white pus-like substance. They are several millimeters in diameter and quite painful.
Acne prevention often becomes essential during our teenage years. It can cause great embarrassment at an age when young people are very concerned about how they look. Pubescent girls need to pay greater attention to acne prevention because of the hormonal upsurges associated with the onset of menstruation. Most affected teenagers address acne prevention with manic scrubbing. But this does little help as acne is not caused by lack of hygiene of body; rather it is affected by poor hygiene of skin. Avoiding fat-laden junk food items does help but not much.  The best course of action is using a mild cleansing agent to wash down the entire face and regular shampooing of hair. Many things are sold to treat acne, the most popular being benzoyl peroxide.

Acne Treatment Options
•    Killing the bacteria that grow in the blocked follicles. This can be done by ingesting antibiotic medication, or by putting antibiotics on the skin.
•    Removing oil on the skin can be done by taking drugs that contain Vitamin A.
•    Removing dead skin cells can be done by treatment with salicylic acid. This encourages the skin to peel away the top layer of cells.