Cystic acne, also known as nodulocystic acne, is a severe form of acne wherein
acne develops into small cysts. Although not uncommon, it is rarer than other
types of
acne. Like other forms, it is caused by an excess buildup of sebum in the pores and, contrary to popular belief, is not caused by, nor is it affected by, hygiene or the lack thereof.
The cysts are usually filled with a white pus-like substance. They are usually several millimeters in diameter, and can be quite painful.