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Normally empties onto the skin surface through the opening of the follicle, commonly called a pore. Cells called keratinocytes line the follicle.The hair, sebum, and keratinocytes that fill the narrow follicle may produce a plug, which is an early sign of acne. The plug prevents sebum from reaching the surface of the skin through a pore. The mixture of oil and cells allows bacteria Propionibacterium acnes (P. acnes) that normally live on the skin to grow in the plugged follicles. These bacteria produce chemicals and enzymes and attract white blood cells that cause inflammation. (Inflammation is a characteristic reaction of tissues to disease or injury and is marked by four signs: swelling, redness, heat, and pain.) When the wall of the plugged follicle breaks down, it spills everything into the nearby skin – sebum, shed skin cells, and bacteria – leading to lesions or pimples. People with acne frequently have a variety of lesions, some of which are shown in the diagrams below. The basic acne lesion, called the comedo (KOM-e-do), is simply an enlarged and plugged hair follicle. If the plugged follicle, or comedo, stays beneath the skin, it is called a closed comedo and produces a white bump called a whitehead. A comedo that reaches the surface of the skin and opens up is called an open comedo or blackhead because it looks black on the skin's surface. This black discoloration is due to changes in sebum as it is exposed to air. It is not due to dirt. Both whiteheads and blackheads may stay in the skin for a long time. The exact cause of acne is unknown, but doctors believe it results from several related factors. One important factor is an increase in hormones called androgens (male sex hormones). These increase in both boys and girls during puberty and cause the sebaceous glands to enlarge and make more sebum. Hormonal changes related to pregnancy or starting or stopping birth control pills can also cause acne. Another factor is heredity or genetics. Researchers believe that the tendency to develop acne can be inherited from parents. For example, studies have shown that many school-age boys with acne have a family history of the disorder. Certain drugs, including androgens and lithium, are known to cause acne. Greasy cosmetics may alter the cells of the follicles and make them stick together, producing a plug.
How Is Acne Treated? Acne is often treated by dermatologists (doctors who specialize in skin problems). These doctors treat all kinds of acne, particularly severe cases. Doctors who are general or family practitioners, pediatricians, or internists may treat patients with milder cases of acne. The goals of treatment are to heal existing lesions, stop new lesions from forming, prevent scarring, and minimize the psychological stress and embarrassment caused by this disease. All medicines can have side effects. Some medicines and side effects are mentioned in this booklet. Some side effects may be more severe than others. You should review the package insert that comes with your medicine and ask your health care provider or pharmacist if you have any questions about the possible side effects. Depending on the extent of the problem, the doctor may recommend one of several over-the-counter (OTC) medicines and/or prescription medicines. Some of these medicines may be topical (applied to the skin), and others may be oral (taken by mouth). The doctor may suggest using more than one topical medicine or combining oral and topical medicines. Treatment for Blackheads, Whiteheads, and Mild Inflammatory Acne Doctors usually recommend an OTC or prescription topical medicine for people with mild signs of acne. Topical medicine is applied directly to the acne lesions or to the entire area of affected skin. There are several OTC topical medicines used for mild acne. Each works a little differently. Following are the most common ones:
Topical OTC medicines are available in many forms, such as gels, lotions, creams, soaps, or pads. In some people, OTC acne medicines may cause side effects such as skin irritation, burning, or redness, which often get better or go away with continued use of the medicine. If you experience severe or prolonged side effects, you should report them to your doctor. OTC topical medicines are somewhat effective in treating acne when used regularly; however, it may take up to 8 weeks before you see noticeable improvement. Treatment for Moderate to Severe Inflammatory Acne People with moderate to severe inflammatory acne may be treated with prescription topical or oral medicines, alone or in combination.
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:
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 important mechanisms.
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). In addition, acne-prone skin
has been shown to be insulin resistant [citation needed]. Deficient personal hygiene. Acne is not caused by dirt. This misconception
probably comes from the fact that comedones look like dirt stuck in the
openings of pores. The black color is simply not dirt but compact keratin.
In fact, the blockages of keratin that cause acne occur deep within the
narrow follicle channel, where it is impossible to wash them away. These
plugs are formed by the failure of the cells lining the duct to separate and
flow to the surface in the sebum created there by the body. The bacteria
involved are normally present on the skin but they multiply preferentially
in the very low oxygen environment of these plugged pores. Very little
variation among individuals with acne is due to hygiene. Anything beyond
very gentle cleansing can actually worsen existing lesions and even
encourage new ones by damaging or overdrying skin. On the other hand some
commercial cleansers have been shown to help empty plugged pores. Timeline of acne treatment The history of acne reaches back to the dawn of recorded history. In Ancient Egypt, it is recorded that several pharaohs were acne sufferers. From Ancient Greece comes the English word 'acne' (meaning 'point' or 'peak'). Acne treatments are also of considerable antiquity:
Some old treatments, like laxatives, have fallen into disuse but others,
like spas, are recovering their popularity.
A combination of treatments can greatly reduce the amount and severity of acne in many cases. Those treatments that are most effective tend to have greater potential for side effects and need a greater degree of monitoring, so a step-wise approach is often taken. Many people consult with doctors when deciding which treatments to use, especially when considering using any treatments in combination.
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