Understand cystic acne. Acne is a general term that describes a variety of different types of pimples, blackheads, pustules, whiteheads and cysts. Cystic acne are nodules that are red, raised, often 2–4 mm in size and nodular and are the most severe form of acne. The infection in a cystic acne is deeper than that in other pustules or whiteheads. Cystic acne is painful.
Identify a ganglion cyst. These are the most common types of lumps found on the hand and wrist. They are not cancerous and often harmless. Filled with fluid, they can quickly appear, disappear or change in size. They do not require treatment unless they interfere with function or are unacceptable in appearance.