What is acne? What are pimples?

A normal follicle looks like this:

For reasons no one completely understands, follicles, often called pores, sometimes get blocked. Sebum (oil) which normally drains to the surface gets blocked and bacteria begins to grow. Both whiteheads and blackheads start out as a "microcomedone". The picture below is a "microcomedone":

Whitehead When the trapped sebum and bacteria stay below the skin surface, a whitehead is formed.	Blackhead A blackhead occurs when the trapped sebum and bacteria partially open to the surface and turn black due to melanin, the skin's pigment. Blackheads can last for a long time because the contents very slowly drain to the surface.

Either way, blackheads and whiteheads are filled with trapped sebum and bacteria.

Acne is a skin condition that occurs due to the overproduction of oil by the oil glands of the skin. The oil that normally lubricates the skin gets trapped in blocked oil ducts and results in what we know as pimples, blackheads, and whiteheads on the surface of skin. Sometimes it also includes deeper skin lesions that are called cysts.

• Pimples are small skin swellings that sometimes contain pus.
• Blackheads are dark formations on the skin due to an accumulated mixture of oil and cells in a blocked skin pore.
• Whiteheads are small flesh-or white-colored bumps due to skin pore blockage.
• Cysts are closed sacs beneath the skin or deeper that contain fluid or semisolid substances.

The areas of the skin that are most susceptible to acne are those areas that contain the largest number of oil glands. For example, it is estimated that there are 2,000 oil glands per square inch on the forehead alone. The face, chest, shoulders, and back are the areas with the highest population of oil glands.

Acne commonly occurs in people between their teenage years and their 20s. However, it is not restricted to this age. Older adults and children can also have acne.

Facts About Acne

• In most people, acne will last for about three to four years and in 15% of the cases, acne can continue for eight-12 years.
• In a smaller percentage (5%), acne will last beyond age 25 and can continue up to age 40.
• In women particularly, acne may not occur until age 25.
• In 70% of the cases, women will notice a flare-up in the acne condition prior their menstrual period, perhaps due to an increase of androgens. Androgens are steroid hormones responsible for the development and maintenance of male physical characteristics.
• The more severe cases of acne tend to occur most often in men, because they produce more of the male hormones that stimulate acne formation.
• Women with a lot of body or facial hair, and those who have irregular periods, may be at increased risk of acne. These women may want to have their hormone levels evaluated by a physician.