Acne Health Article

Definition

Acne is a skin disorder that leads to an outbreak of lesions called pimples or "zits." The most common form of the disease is called acne vulgaris—the rash that affects many adolescents. Acne vulgaris is triggered by the hormonal changes that occur in puberty.

Description

Acne is a condition in which pimples appear on the face, chest, and back. In teenagers, acne usually appears on the forehead, nose, and chin. It is caused by the overproduction of sebum. Sebum is an oily substance that forms in glands just under the surface of the skin called sebaceous glands. Sebum normally flows out hair follicles onto the skin to act as a natural skin moisturizer. The glands are connected to hair follicles that allow the sebum, or oil, to empty onto the skin through a pore.

If hair follicles become blocked by sebum, dead skin cells, and bacteria, acne is the result. The sebaceous gland units are most commonly found on the face, neck, and back.

During puberty, there are increased levels of the male hormone androgen. High levels of androgen cause excess sebum to form. Sometimes the sebum combines with dead, sticky skin cells and bacteria called Propioni-bacterium acnes (P. acnes) that normally live on the skin. The mixture of oil and cells allows the bacteria to grow in the plugged follicles. When this happens, a hard plug called a comedo can form. A comedo is an enlarged hair follicle. It can take the following forms:

• a blackhead, which is a comedo that reaches the skin's surface and looks black
• a whitehead, which is a comedo that is sealed by keratin, the fibrous protein produced by the skin cells and looks like a white bump.

In addition, pimples can form on the skin. Types of pimples include:

• papules, which are small, red bumps that may be tender to the touch
• pustules, which are pus-filled lesions that are often red at the base
• nodules, which are large, painful lesions deep in the skin
• cysts, which are painful pus-filled lesions deep in the skin that can cause scarring

Pimples form when the follicle is invaded by the P. acnes bacteria. The damaged follicle weakens and bursts open, releasing sebum, bacteria, skin cells, and white blood cells into surrounding tissues. Scarring happens when new skin cells are created to replace the damaged cells. The most severe type of acne includes both nodules and cysts.

Demographics

Acne affects as many as 17 million people in the United States, making it the most common skin disease. Acne usually begins at puberty and worsens during adolescence. Nearly 85 percent of people develop acne at some point between ages 12 to 25. As many as 20 million teens have the condition. Acne may appear as early as age 10, and even may be found in some newborns. Some people may continue to be affected by acne after age 30.

Causes and symptoms

The exact cause of acne is as of 2004 not known. There are several risk factors that make acne more likely to occur:

• Age. Adolescents are more likely to have acne.
• Disease. Certain hormonal disorders such as polycystic ovarian syndrome make acne more likely.
• Hormonal changes. Acne can flare up before menstruation. An increase in the male hormone androgen during puberty (seen in both males and females) causes the sebaceous glands to overproduce androgen. Boys have more severe acne than girls.
• Heredity. Some individual are genetically more susceptible to acne.
• Drugs. Steroids and performance enhancing drugs, oral contraceptives, antibiotics, antidepressants, and tranquillizers such as lithium are known to cause acne.
• Cosmetics. Oily cosmetics can plug up hair follicles.

Other factors can worsen acne or cause it to flare up:

• Environmental irritants. Air pollution and high humidity can worsen acne, as can exposure to greasy environments such as working in a fast food restaurant.
• Friction. Rubbing the skin vigorously or exposure to constant friction from backpacks or tight collars can worsen acne.
• Personal hygiene. Picking at pimples or scrubbing the skin too hard can result in worsened acne.

Factors that do not cause acne include:

• chocolate and greasy foods
• stress

When to call the doctor

A healthcare provider should be contacted under the following circumstances:

• Painful nodules and cysts are present.
• Over-the-counter medications have not been effective.
• Acne lesions are causing scarring.
• Acne is causing dark skin to have darker patches when lesions heal.
• Acne is causing embarrassment or self-consciousness.
• Acne is creating emotional upset.

Acne may be treated by the family doctor. More severe cases may be referred to a dermatologist (skin doctor) or an endocrinologist (doctor who treats hormonal/glandular disorders).