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Acne is a pustular infection of the skin, caused by changes in the sebaceous glands. Excessive secretion of oils from the glands combine with naturally occurring dead skin cells to block the hair follicles. Oil secretions build up beneath the blocked pore, providing a perfect environment for the skin bacteria Propionibacterium acnes to multiply uncontrolled. In response, the skin inflames, producing the visible lesion. The face, chest, back and upper arms are especially exposed.

The infection is common in puberty as a result of an abnormal response to normal levels of the male hormone testosterone. The response for most people diminishes over time and acne thus tends to disappear, or at least decrease, after one reaches early adulthood. There is, however, no way to predict how long it will take for it to disappear entirely, and some individuals will continue to suffer from acne decades later, into their thirties and forties and even beyond.

Acne affects a large percentage of humans at some stage in life. Aside from scarring its main effects are psychological, such as reduced self-esteem and depression. Acne usually appears during adolescence, when people already tend to be at their most socially-insecure. For this reason acne should be treated if severe.

Causes for acne

Exactly why some people get acne and some do not is not fully known. It is known to be partly hereditary. Several factors are known to cause acne:

  • Hormonal activity
  • Hyperactive sebaceous glands
  • Accumulation of dead skin cells
  • Bacteria in the pores
  • Skin irritation or scratching of any sort
  • Anabolic steroids
  • Birth control pills, however many women have reported reduced acne while on the pill
    Those exposed to high levels of chlorine compounds, particularly chlorinated dioxins, often develop severe, long-lasting acne, known as Chloracne.

Not causes for acne

Since the medical knowledge about acne is still relatively small, many misconceptions and rumours about what causes acne exits:

  • Diet. It is not impossible that a changed diet can help clear acne for a certain individual. But no general correlation has been found. Chocolate, chips, sugar, milk and seafood among others have not been shown to effect acne.
  • Deficient personal hygiene. Acne is not caused by dirt. This misconception probably comes from the fact that blackheads by their nature are black and the acne infected skin, therefore, looks dirty.
  • Sex. Rumours have had it that both celibacy and masturbation are causes for acne. This is not the case.


There is a myriad of products sold for the treatment of acne, many of them without any scientifically proven effects. However, a combination of treatments can usually prevent acne in all but the most severe cases. Generally there are three types of treatments that have been proven effective:

Killing the bacteria that are caused by the blocked follicles. This is done either by the intake of antibiotics like tetracyclines, or by treating the affected areas externally with bactericidal substances like benzoyl peroxide. However, reducing the p.acnes bacteria will not, in itself, do anything to reduce the oil secretion that is the initial cause of the blocked follicles. Therefore, acne will generally reappear quite soon after the end of treatment ? days later in the case of topical applications, and weeks later in the case of oral antibiotics.

Reducing the secretion of oils from the glands. This is done by a great daily intake of Vitamin A derivates like isotretinoin over a period of a few months. The product is sold by Roche under the names Accutane in USA and Roaccutane in Europe. Isotretinoin has been shown to be very effective in treating severe acne and is effective in up to 80% of the patients. The drug has a much longer effect than anti-bacterial treatments and will often cure acne for good. The treatment requires close medical examination by a dermatologist since the drug has many known side effects. The most common are dry skin and nosebleed. It can also permanently damage the liver and cause depression. The drug also causes birth defects if women become pregnant while taking it.

Exfoliating the skin. The topical treatment salicylic acid for example encourages the peeling of the top layer of skin to prevent a build-up of dead skin cells which combine with skin oil to block pores. It also helps to unblock clogged pores.

Popping a pimple or any physical acne treatment should not be attempted by anyone but a qualified dermatologist. Pimple popping irritates skin, can spread the infection deeper into the skin and can cause permanent scarring.

Acne scars

Severe acne often leaves nasty scars where the skin gets a "volcanic" shape. Acne scars are very hard (and expensive) to treat and it is unusual for the scars to be successfully removed completely. In those cases, scar treatment may be appropriate. The most commonly used forms of scar treatments are:

Dermabrasion. The top layer of the skin is removed to make the scar look less pitted. It makes the scar less visible but does not remove it completely. Multiple treatments may be necessary to get the desired results.

Laser resurfacing. A laser is used to burn off the top layer of the skin.

Punch excision. The scar is excised with a punch tool and the edges are sutured together.

Chemical peels. Different types of acid are applied to the skin so that a smoother layer can surface.

Subcision. The scar is detached from deeper tissue, allowing a pool of blood to form under the scar which helps form a connective tissue under the scar, leveling it with the surface.

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