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Tuesday, May 22, 2007

Acne Care



Acne Care:
Acne is a disease of skin. They are also known as pimples and spots.
Acne (acne vulgaris) is a dermatologic condition characterized by lesions that most often appear on the face and neck, but also develop on the chest, back, shoulders and upper arms. Approximately 80 percent to 95 percent of adolescents develop some degree of acne, but its prevalence declines over subsequent years until middle age, when it still affects about 12 percent of women and 3 percent of men (Cordain L et al 2002; Rossen MH et al 1993). Acne can be a significant source of misery, and it is difficult to treat. A galaxy of over-the-counter (OTC) medications and washes are sold and marketed for acne (many with harmful chemicals), along with strong prescription medications.

Acne is characterized by pimples, cysts and abscesses. It occurs when the pores in the skin are blocked, trapping oil, dead skin and bacteria in the hair follicles. Under normal circumstances, glands (called sebaceous glands) attached to hair follicles secrete an oily substance known as sebum. This sebum typically travels up the hair follicle and onto the skin. However, if the hair follicle is blocked, the sebum can’t get out, sometimes causing the formation of a blackhead. This is the result of the blocked oil oxidizing, causing inflammation and an influx of white blood cells. Meanwhile, normally present bacteria (Propionibacterium acnes) begin to break down the trapped sebum within the hair follicle. This results in further inflammation, as white blood cells attack the bacteria. Pus forms as the lesion enters the whitehead stage. In more severe stages, an abscess—a pus-filled pocket within the skin—may form. Although most pimples won’t leave lasting scars, anything that damages the dermis (the layer of skin just underneath the epidermis) can leave a permanent scar.

The condition is most common in puberty. It is considered 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 his or her early twenties. 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[specify] of humans at some stage in life.

The most common form of acne is known as "acne vulgaris", meaning "common acne." Many teenagers get this type of acne. Excessive secretion of oils from the sebaceous glands accompanies the plugging of the pores with naturally occurring dead skin cells (corneocytes) blocking hair follicles. The accumulation of these corneocytes in the duct appears to be due to a failure of the normal keratinization process in the skin which usually leads to shedding of skin cells lining the pores. Oil secretions are said to build up beneath the blocked pore, providing a perfect environment for the skin bacteria Propionibacterium acnes and the lipophilic (oil/lipid-loving) yeast Malassezia[citation needed] to multiply uncontrollably. Under the microscope, however, there is no evidence of pooled trapped sebum. Indeed the oil percolates through the plugged duct onto the surface. In response to the bacterial and yeast populations, the skin inflames, producing the visible lesion. The face, chest, back, shoulders and upper arms are especially affected. The typical acne lesions are: comedones, papules, pustules, nodules and inflammatory cysts known as cystic acne, one of the more severe forms. These are more inflamed and pus-filled or reddish bumps, that can easily lead to scarring or serious infections. Non-inflamed 'sebaceous cysts', more properly called epidermoid cysts, occur either in association with acne or alone but are not a constant feature. After resolution of acne lesions, prominent unsightly scars may remain.


Acne can be caused by environmental and genetic factors, but genetics seems to predominate. In one large twin study, for example, 81 percent of disease variance—that is, the difference from what would normally be expected—was attributed to genetic effects, and the remaining 19 percent to environmental factors. The study also showed that having a family history of acne is significantly associated with increased personal risk.

The role of hormones in the development of acne is apparent at puberty, when there is a surge in the production of male hormones (which are present in both males and females), enlarging the sebaceous glands in the skin. This results in increased sebum production, which leads to the aforementioned plug formation, creating as well a fertile environment in which bacteria can multiple. Unlike male-hormone androgens, female-hormone estrogens have a beneficial effect on acne, which is why some doctors recommend birth control pills for women who have acne. But when a woman’s estrogen levels decline, as they do just before the beginning of a menstrual cycle, acne may worsen.

Acne or acne-like lesions can develop in response to various substances, including corticosteroids, lithium (Yeung CK et al 2004), and some psychotropic drugs. Other causes include exposure to tobacco smoke, coal tar derivatives, industrial oils, and chlorinated hydrocarbons. Further, oils in aerosol sprays, as well as excessive washing or scrubbing of the skin, can exacerbate acne because these cause increased skin-oil production. Use of many types of cosmetics, oil-based hair products, and suntan lotions can block oil glands and worsen acne; hypoallergenic, oil-free, water-based products that do not clog pores are better choices (Russell JJ 2000). Despite popular opinion, the conventional medical view is that acne is not caused by poor hygiene or by eating specific foods, such as chocolate, pizza, and soda.