Stages of acne

There are various terms that describe different forms of acne, such as comedones, papules, pustules, nodules, and cysts. Basically, comedones (plural for comedo) are the name given to plugged follicles: an open comedo is called a blackhead because the surface is visible and turns “black” when it’s exposed to air. A closed comedo is a whitehead, which is like a blackhead, but is closed at the surface. Plugged follicles can become irritated and swollen enough to burst, thus affecting surrounding tissues. If a plugged follicle erupts above the skin’s surface, it becomes a pimple; when it erupts below the surface, it forms a red lump, such as a nodule or cyst.

How bad can acne get?

Mild acne consists of a few lesions that are close to the surface, and not deep or inflamed.

Moderate acne is marked by deeper nodular lesions and some redness.

Severe acne involves many lesions, multiple cysts, and a great deal of redness and inflammation.