Types of Pimples

Signs and symptoms of pimples - Types of pimples

Whiteheads - also known as a closed comedo. These are very small and remain under the skin, appearing as a small, flesh-colored papules.
Blackheads - also known as an open comedo. These are clearly visible; they are black and appear on the surface of the skin. Some people mistakenly believe they are caused by dirt, because of their color, and scrub their faces vigorously - this does not help and may irritate the skin and cause other problems.

Papules - these are small, solid, rounded bumps that rise from the skin. The bumps are often pink. Pustules - these are pimples full of pus. They are clearly visible on the surface of the skin. The base is red and the pus is on the top.
Nodules - these are morphologically similar (similar structure) to papules, but larger. They can be painful and are embedded deep in the skin. Cysts - these are clearly visible on the surface of the skin. They are filled with pus and are usually painful. Cysts commonly cause scars.

How common are pimples (acne)?

Acne is the most common skin disease for adolescents. According to the British Medical Journal (Clinical Evidence, Authors: Sarah Purdy, David DeBerker):

More than 80% of teenagers get acne at some point. A community sample of 14 to 16 year-olds in the United Kingdom revealed that acne affected 50% of them. A sample study of adolescents in New Zealand found acne was present in 91% of boys and 79% of girls. A sample study of adolescents in Portugal found that the average prevalence of acne (in both sexes) was 82%. 30% of teenagers with acne required medical treatment because of its severity.

General practitioners (GPs, primary care physicians) in the UK reported that 3.1% of 13 to 25 year-old patients visited them complaining of acne. The incidence of acne is similar in both adult males and females.     Doctors report that acne appears to peak at 17 years of age. Acne incidence (presence, occurrence) in adults is increasing, doctors report. We don't know why.

Source : medical news