Acne is an inflammatory
disease of the skin, caused by changes in the pilosebaseous units (skin
structures consisting of a hair follicle and its associated sebaceous
gland). The most common form of acne is known as "acne vulgaris",
which means common acne. 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 is especially affected.
The typical lesions of acne
are: small whitish or skin-colored bumps (whiteheads) or blackish
elevations (blackheads). More inflamed rashes take the form of pus-filled,
or reddish bumps, even boil-like tender swellings. After these lesions are
cured, prominent unsightly scars may remain.
Picture of Acne on the face
The condition 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 after one turns 30. There is, however, no way
to predict how long it will take for it to disappear entirely, and some
individuals may suffer from acne all their life.
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. 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. Several factors are linked with
· 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
· Exposure to high levels of chlorine compounds.
· Traditionally, attentin has focused mostly on
over-production of sebum as the main contributing factor of acne.
Formation of Acne
Nowadays, more attention is
being given to narrowing of the follicle channel. Abnormal shedding of the
cells lining the follicle and water retention in the skin (swelling the
skin and so pressing the follicles shut) have all been put forward as
mechanisms involved, but there does not appear to be much conclusive
medical research on the subject.
Since the medical knowledge
about acne is still relatively small, many misconceptions and rumours about
what causes acne exist:
Diet - Chocolate, chips,
sugar, milk and seafood among others have not been shown to affect acne
However, there is no
scientific evidence that this is the case.
There are a myriad of
products sold for the treatment of acne, many of them without any
scientifically proven effects. However, a combination of treatments can
greatly reduce the amount and severity of acne in many cases. There are
four types of treatments that have been proven effective:
1. Killing the bacteria that are harbored in 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 or erythromycin. However, reducing the bacteria will not,
in itself, do anything to reduce the oil secretion and abnormal cell
behaviour that is the initial cause of the blocked follicles. Therefore,
acne may reappear after the end of treatment
2. Reducing the secretion of oils from the glands. This is
done by daily oral intake of Vitamin A derivates like isotretinoin over a
period of a few months. Isotretinoin has been shown to be very effective in
treating severe acne for good. However, the treatment requires close
medical examination by a dermatologist since the drug has many known side
effects. The most common side effects are dry skin and nosebleed. It can
also permanently damage the liver. Because of this, the drug is typically
used given a last resort after milder treatments have proven insufficient.
3. Normalizing the follicle cell lifecycle. A group of
medications for this are topical retinoids such as Tretinoin, Adapalene and
Tazarotene. They are related to Vitamin A, but they are administered as
topicals and have much milder side effects. They can give significant
irritation of the skin.
4. Exfoliating the skin. This can be done either
mechanically, using an abrasive cloth or a liquid scrub, or chemically.
Common chemical exfoliating agents include salicylic acid and glycolic
acid, which encourage 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 already clogged pores. Note that the phrase
"peeling" is not meant in the visible sense of shedding, but
rather as the destruction of the top layer of skin cells at the microscopic
level. Moisturizers and anti-acne topicals containing chemical exfoliating
agents are commonly available over-the-counter.
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.
· Lasers have been in use for some time to reduce the
scars left behind by acne, but research is now being done on lasers for
prevention of acne formation.
· As of 2004, this is still mostly at the stage of
medical research rather than established treatment.
· Because acne appears to have a significant hereditary
link, there is some expectation that cheap whole-genome DNA sequencing may
help isolate the body mechanisms involved in acne more precisely, possibly
leading to a more satisfactory treatment However, as of 2004 DNA sequencing
is not yet cheap and all this may still be decades off. It is also possible
that gene therapy could be used to alter the skin's DNA.
Severe acne often leaves
small 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. In those cases, scar treatment may be appropriate.
The most commonly used forms of scar treatments are:
· Laser resurfacing.
· Punch excision.
· Chemical peels