Acne

Acne is an inflammatory disease of the skin, caused by changes in the pilosebaceous 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.

Causes of 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 be linked to acne:

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

• Hormonal activity, such as menstrual cycles
• Stress, through increased output of hormones from the adrenal (stress) glands
• Hyperactive sebaceous glands, secondary to the three hormone sources above
• Accumulation of dead skin cells
• Bacteria in the pores, to which the body becomes 'allergic'
• Skin irritation or scratching of any sort will activate inflammation
• Anabolic steroids - the body-building steroids
• Any medication containing halogens (iodides, chlorides, bromides), lithium, barbiturates, or androgens
• Exposure to high levels of chlorine compounds, particularly chlorinated dioxins, can cause severe, long-lasting acne, known as Chloracne

Traditionally, attention has focused mostly on hormone-driven over-production of sebum as the main contributing factor of acne. More recently, more attention has been given to narrowing of the follicle channel as a second main contributing factor. Abnormal shedding of the cells lining the follicle, abnormal cell binding ("hyperkeratinization") within 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. The most likely mechanism of plugging is a failure of terminal differentiation, the same process whereby leaves undergo a metabolic process that separates them from their twig or stem. Failure of this process may be linked to the anoxia produced by increased pressure in the lumen of the duct. This pressure in turn is produced by the hormone-induced overproduction of the duct lining cells. There is a very tight wrap around the duct preventing over-expansion, so internal pressures are thought to build up as a result. There is to date only circumstantial evidence to support this explanation but there is no conclusive proof of this theory.

Related Topics:
Shedding - Hyperkeratinization

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Several hormones have been linked to acne: the male hormones testosterone, dihydrotestosterone (DHT) and dehydroepiandrosterone sulfate (DHEAS), as well as insulin-like growth factor 1 (IGF-I).

Related Topics:
Hormone - Male hormone - Testosterone - Dihydrotestosterone - Dehydroepiandrosterone sulfate - Insulin-like growth factor 1

~ ~ ~ ~ ~ ~ ~ ~ ~ ~