Acne

Acne is an inflammation of the skin that causes blackheads, whiteheads, and red spots usually called "pimples" or "zits." The most common type of acne is acne vulgaris (vulgaris means common). Acne appears most often on the face, but can also be a nuisance on your chest, back, and upper arms. Acne affects about 90% of adolescents, as well as 20% to 30% of individuals aged 20 to 40 years. It accounts for more doctor visits than any other skin problem.

Acne isn't life-threatening, but it can be upsetting and disfiguring and cause psychosocial problems. Acne can also lead to serious and permanent scarring.

Acne forms when hair follicles become blocked by dead skin cells mixed with sebum. Sebum is an oily substance produced by glands called sebaceous glands that are attached to the hair follicles. In people with acne, these glands overproduce sebum that mixes with dead skin cells to form a plug that blocks the follicles. This creates the environment for a bacteria species that commonly lives on your skin called Cutibacterium acnes to overgrow and cause inflammation.

Hormones can cause an outbreak of pimples, or increase the number you get. The hormones that are active during puberty also trigger your sebaceous glands to grow and produce more sebum. Sebaceous glands are highly sensitive to hormone changes. The hormones with the greatest effect on the oil glands are the androgens, the male hormones. Both men and women have androgens, but men have more.

In women, these hormones can also cause acne during the menstrual cycle, and that's why women often find that acne continues into adulthood.

Eating junk food and chocolate normally has nothing to do with acne. Greasy hair and skin also doesn't cause acne, but they're often a sign of overactive sebaceous glands, which can cause acne. Research suggests that stress may worsen existing acne, but it doesn't cause it.

A tendency to get acne can run in families. Family history can increase the chances of getting severe acne. However, the role of family history is less certain for mild acne, as young adolescents commonly have mild acne regardless of family history.

Things that irritate your skin can also cause acne. These include:

• rubbing or friction from clothing
• contact with a dog's tongue (e.g., after a friendly lick)
• skin contact with certain sports equipment
• certain cosmetics (oil-based cosmetics)
• skin exposure to extreme temperatures

Taking corticosteroid medications can also cause an acne-like condition.

Acne symptoms vary from person to person. They include:

• blackheads (black spots the size of a pinhead) are open right on the surface of your skin (superficial) and don't leave scars
• whiteheads or pustules, the most common type of acne, are usually the first lesions people get - they don't turn black because they're not exposed to the air
• deep pustules and cysts look irritated; they're usually red and swollen with visible pus
• deep acne can be more severe – it's usually red, inflamed, warm, tender, filled with pus, and painful to touch

Deep acne often appears on the back and chest. It's usually the most difficult type of acne to treat and may leave scarring. Deep acne includes pustules and cysts, both of which can appear on the skin's surface. Some, however, are deep in the layers of the skin. If they burst, the pus that's released will cause more lesions.

Deep acne can lead to scarring. Picking at or squeezing the pimples often leaves a pitted appearance that may or may not be permanent. Scarring is more common in men because deep acne affects more men than women.

Acne is diagnosed by its appearance. Your doctor may do a physical exam and look at your medical and personal history to rule out any other possibilities. Your doctor may ask about things like cosmetics and any medications you're taking.