Here is the definition from the US National Library of Medicine site Medlineplus Medlineplus and I quote:

“Acne is a common skin disease that causes pimples. Pimples form when hair follicles under your skin clog up. Most pimples form on the face, neck, back, chest and shoulders. Anyone can get acne, but it is common in teenagers and young adults. It is not serious, but it can cause scars.

No one knows exactly what causes acne. Hormone changes, such as those during the teenage years and pregnancy, probably play a role. There are many myths about what causes acne. Chocolate and greasy foods are often blamed, but there is little evidence that foods have much effect on acne in most people. Another common myth is that dirty skin causes acne; however, blackheads and pimples are not caused by dirt. Stress doesn’t cause acne, but stress can make it worse.”

Acne is a skin condition characterized by whiteheads, blackheads, and inflamed red pimples or “zits.”
The major symptoms include:

* Blackheads
* Crusting of skin eruptions
* Cysts
* Inflammation around the skin eruptions
* Pustules
* Redness around the skin eruptions
* Scarring of the skin
* Whiteheads

Your doctor can diagnose acne based on the appearance of the skin. Testing is usually not required.

Here are their recommendations for the treatment for Acne:

The following self-care steps can be used to lessen the effects of acne:

* Gently clean your with a mild, non-drying soap (such as Dove, Neutrogena, or Basics). Wash only once or twice a day, including after exercising. Avoid excessive or repeated skin washing.
* Shampoo your hair daily, especially if it’s oily. Comb or pull your hair back to keep the hair out of your face. Avoid the use of tight headbands.
* Try not to squeeze, scratch, pick, or rub the pimples. Although it might be tempting to do this, it can lead to scarring and skin infections.
* Avoid touching your face with your hands or fingers.
* Avoid greasy cosmetics or creams. Look for water-based or “non-comedogenic” formulas. Remove all make-up at night.

If the above steps do not clear up your blemishes to an acceptable level, try over-the-counter acne medications. These creams and lotions are applied directly to the skin. They may contain benzoyl peroxide, sulfur, resorcinol, or salicylic acid. They work by killing bacteria, drying up the oil, and causing your skin to peel.

If the pimples are still a problem, a dermatologist can prescribe stronger medications and discuss other options with you.

The options include prescription medicines such as:

* Oral antibiotics (taken by mouth) such as minocycline, doxycycline, and tetracycline
* Topical antibiotics (applied to the skin) such as clindamycin or erythromycin
* Retinoic acid cream or gel (Retin-A) and isotretinoin pills (Accutane) — pregnant women and sexually active adolescent females should NOT take Accutane, as it causes severe birth defects; Women taking Accutane should use two forms of birth control before starting the drug
* Prescription formulas of benzoyl peroxide, sulfur, resorcinol, salicylic acid

Birth control pills can sometimes help clear up acne. (In some cases, though, they may make it worse.)

Your doctor may also suggest chemical skin peeling, removal of scars by dermabrasion, or removal or drainage of cysts.

A small amount of sun exposure may improve acne. However, excessive exposure to sunlight or ultraviolet rays is not recommended because it increases the risk of skin cancer.

The Causes of Acne

Acne occurs when tiny holes on the surface of the skin, called pores, become clogged. Each pore is an opening to a canal called a follicle, which contains a hair and an oil gland. Normally, the oil glands help keep the skin lubricated and help remove old skin cells. When glands produce too much oil, the pores can become blocked, accumulating dirt, debris, and bacteria. The blockage is called a plug or comedone.

The top of the plug may be white (whitehead) or dark (blackhead). If it ruptures, the material inside, including oil and bacteria, can spread to the surrounding area and cause an inflammatory reaction. If the inflammation is deep in your skin, the pimples may enlarge to form firm, painful cysts.

Acne commonly appears on the face and shoulders, but may also occur on the trunk, arms, legs, and buttocks.

Acne is most common in teenagers, but it can happen at any age, even as an infant. Three out of four teenagers have acne to some extent, probably caused by hormonal changes that stimulate oil production. However, people in their 30s and 40s may also have acne.

Acne tends to run in families and can be triggered by:

* Hormonal changes related to menstrual periods, pregnancy, birth control pills, or stress
* Greasy or oily cosmetic and hair products
* Certain drugs (such as steroids, testosterone, estrogen, and phenytoin)
* High levels of humidity and sweating

Despite the popular belief that chocolate, nuts, and other foods cause acne, this does not seem to be true.

The prognosis for Acne is generally good. Acne usually subsides after adolescence, but may last into middle age. The condition generally responds well to treatment after a few weeks, but may flare up from time to time. Scarring may occur if severe acne is not treated. Some people, especially teenagers, can become significantly depressed if acne is not treated.

Although the prognosis for most of us is generally good, there can be both short and long term complications from this disorder.

The possible complications include:

* Changes in skin color
* Cysts
* Damage to self-esteem, confidence, personality, and social life
* Permanent facial scars
* Side effects of medications such as those from Accutane (including very dry skin and mucous membranes, high triglyceride levels, liver damage, and birth defects in an unborn baby; call your doctor right away if you become pregnant while taking this drug)

It is important to consider when to contact your doctor or see a speicalist in skin care (a dermatologist). Do contact one if:

* Self-care measures and over-the-counter medicine have not helped after several months
* Your acne is severe (for example, you have lots of redness around the pimples or you have cysts) or is getting worse
* You develop scars as your acne clears up
For a fuller discussion of the above, please see the following pages:
Acne