According to the American Academy of Dermatology (AAD), acne is the most common skin condition in the United States. It is characterized by blemishes on the face, chest, and back, which form when the pores of the skin become clogged with oily debris, dead skin cells, and bacteria. These clogged pores are called comedones. Mild acne consists of open or closed comedones.
Moderate and severe inflammatory types of acne occur when plugged follicles are invaded by bacteria normally living inside hair follicles and become inflamed. These inflamed areas are called papules; when deeper, they are called pustules. The most severe type of acne consists of cysts (closed sacs) and nodules (hard swellings). Left unchecked, acne can leave discolored areas and permanent scars. Acne typically affects us during our teens to twenties but can also be seen in adults and infants.