Acne is a common skin disease characterized by pimples on the face, chest, and back. It occurs when the pores of the skin become clogged with oil, dead skin cells, and bacteria. Acne affects nearly 17 million people in the United States. While it can arise at any age, acne usually begins at puberty and worsens during adolescence. Nearly 85% of people develop acne at some time between the ages of 12-25 years.

The face, chest, and back are most affected because those areas have the most sebaceous glands. These glands produce sebum, an oily natural moisturizer. The glands are found in hair follicles and open onto the skin through pores. At puberty, sebum production increases. Excess sebum can combine with dead skin cells and form a hard plug, or comedo, which blocks the pore. Mild noninflammatory acne consists of the two types of comedones, whiteheads and blackheads.

Moderate and...