Acne vulgaris (commonly called acne) is a skin disease caused by changes in the pilosebaceous units (skin structures consisting of a hair follicle and its associated sebaceous gland). Severe acne is inflammatory, but acne can also manifest in noninflammatory forms. Acne lesions are commonly referred to as pimples, spots, or zits.
Alternative Names
acne vulgaris; Cystic acne; Pimples; Zits
Causes, incidence, and risk factors
Acne occurs when tiny holes on the surface of the skin, called pores, become clogged. Each pore is an opening to a canal called a follicle, which contains a hair and an oil gland. Normally, the oil glands help keep the skin lubricated and help remove old skin cells. When glands produce too much oil, the pores can become blocked, accumulating dirt, debris, and bacteria. The blockage is called a plug or comedone.The top of the plug may be white (whitehead) or dark (blackhead). If it ruptures, the material inside, including oil and bacteria, can spread to the surrounding area and cause an inflammatory reaction. If the inflammation is deep in your skin, the pimples may enlarge to form firm, painful cysts.Acne commonly appears on the face and shoulders, but may also occur on the trunk, arms, legs, and buttocks.
Acne is most common in teenagers, but it can happen at any age, even as an infant. Three out of four teenagers have acne to some extent, probably caused by hormonal changes that stimulate oil production. However, people in their 30s and 40s may also have acne.Acne tends to run in families and can be triggered by:Hormonal changes related to menstrual periods, pregnancy, birth control pills, or stressGreasy or oily cosmetic and hair productsCertain drugs (such as steroids, testosterone, estrogen, and phenytoin)High levels of humidity and sweatingDespite the popular belief that chocolate, nuts, and other foods cause acne, this does not seem to be true.SymptomsBlackheads .Crusting of skin eruptions .Cysts .Inflammation around the skin eruptions .Pustules .Redness around the skin eruptions .Scarring of the skin .Whiteheads.
Signs and tests
Your doctor can diagnose acne based on the appearance of the skin.
Treatments.
There are many products available for the treatment of acne, many of which are without any scientifically-proven effects. Generally speaking, successful treatments show little improvement within the first two weeks, instead taking a period of approximately three months to improve and start
flattening out. Many treatments that promise big improvements within two weeks are likely to be largely disappointing. However, short bursts of cortisone can give very quick results, and other treatments can rapidly improve some active spots, but usually not all active spots. Modes of improvement are not necessarily fully understood but in general treatments are believed to work in at least 4 different ways (with many of the best treatments providing multiple simultaneous effects):normalising shedding into the pore to prevent blockagekilling P. acnesanti-inflammatory effectshormonal manipulationA 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. There are a number of treatments that have been proven effective: 
Topical bactericidals
Widely available OTC bactericidal products containing benzoyl peroxide may be used in mild to moderate acne. The gel or cream containing benzoyl peroxide is rubbed, twice daily, into the pores over the affected region. Bar soaps or washes may also be used and vary from 2 to 10% in strength. In addition to its therapeutic effect as a keratolytic (a chemical that dissolves the keratin plugging the pores) benzoyl peroxide also prevents new lesions by killing P.acnes. In one study, roughly 70% of participants using a 10% benzoyl peroxide solution experienced a reduction in acne lesions after 6 weeks.Unlike antibiotics, benzoyl peroxide has the advantage of being a strong oxidizer (essentially a mild bleach) and thus does not appear to generate bacterial resistance. However, it routinely causes dryness, local irritation and redness. A sensible regimen may include the daily use of low-concentration (2.5%) benzoyl peroxide preparations, combined with suitable non-comedogenic moisturisers to help avoid overdrying the skin.Care must be taken when using benzoyl peroxide, as it can very easily bleach any fabric or hair it comes in contact with.Other antibacterials that have been used include triclosan, or chlorhexidine gluconate but these are often less effective, but also have fewer side-effects.Prescription-strength benzoyl peroxide preparations do not necessarily differ with regard to the maximum concentration of the active ingredient (10%), but the drug is made available dissolved in a
vehicle that more deeply penetrates the pores of the skin.
Topical antibiotics
Externally applied antibiotics such as erythromycin, clindamycin, Stievamycin, or tetracycline aim to kill the bacteria that are harbored in the blocked follicles. While topical use of antibiotics is equally as effective as oral use, this method avoids possible side effects including upset stomach and drug interactions (e.g. it will not affect use of the oral contraceptive pill), but may prove awkward to apply over larger areas than just the face alone.
Oral antibiotics
Oral antibiotics used to treat acne include erythromycin or one of the tetracline antibiotics(tetracycline, the better absorbed oxytetracycline, or one of the once daily doxycycline, minocycline, or lymecycline). Trimethoprim is also sometimes used (off-label use in UK). However, reducing the P. acnes bacteria wi
ll not, in itself, do anything to reduce the oil secretion and abnormal cell behaviour that is the initial cause of the blocked follicles. Additionally the antibiotics are becoming less and less useful as resistant P. acnes are becoming more common. 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. Furthermore side effects of tetracycline antibiotics can include yellowing of the teeth and an imbalance of gut flora, so are only recommended after topical products have been ruled out.It has been found that sub-antimicrobial doses of antibiotics such as minocycline also improve acne. It is believed that minocycline's anti-inflammatory effect also prevents acne. These low doses do not kill bacteria and hence cannot induce resistance.
Hormonal treatments
In females, acne can be improved with hormonal treatments. The common combined oestrogen/progestogen methods of hormonal contraception have some effect, but the antiandrogen, Cyproterone, in combination with an oestrogen (Diane 35) is particularly effective at reducing androgenic hormone levels. Diane-35 is not available in the USA, but a newer oral contraceptive containing the progestin drospirenone is now available with fewer side effects than Diane 35 / Dianette. Both can be used where blood tests show abnormally high levels of androgens, but are effective even when this is not the case. Along with this, treatment with low dose spironolactone can have anti-androgenetic properties, especially in patients with polycystic ovarian syndrome.If a pimple is large and/or does not seem to be affected by other treatments, a dermatologist may administer an injection of cortisone directly into it, which will usually reduce redness and inflammation almost immediately. This has the effect of flattening the pimple, thereby making it easier to cover up with makeup, and can also aid in the healing process. Side effects are minimal, but may include a temporary whitening of the skin around the injection point; and occasionally a small depression forms, which may persist, although often fills eventually. This method also carries a much smaller risk of scarring than surgical removal.
Tpical retinoids
A group of medications for normalizing the follicle cell lifecycle are topical retinoids such as tretinoin (brand name Retin-A), adapalene (brand name Differin), and tazarotene (brand name Tazorac). Like isotretinoin, they are related to vitamin A, but they are administered as topicals and generally have much milder side effects. They can, however, cause significant irritation of the skin. The retinoids appear to influence the cell creation and death lifecycle of cells in the follicle lining. This helps prevent the hyperkeratinization of these cells that can create a blockage. Retinol, a form of vitamin A, has similar but milder effects and is used in many over-the-counter moisturizers and other topical products. Effective topical retinoids have been in use over 30 years but are available only on prescription so are not as widely used as the other topical treatments. Topical retinoids often cause an initial flare up of acne and facial flushing.
Oral retinoids
inoidsdaily oral intake of vitamin A derivative isotretinoin (marketed as Accutane, Amnesteem, Sotret, Claravis) over a period of 4-6 months can cause long-term resolution or reduction of acne. It is believed that isotretinoin works primarily by reducing the secretion of oils from the glands, however some studies suggest that it affects other acne-related factors as well. Isotretinoin has been shown to be very effective in treating severe acne and can either improve or clear well over 80% of patients. The drug has a much longer effect than anti-bacterial treatments and will often cure acne for good. The treatment requires close medical supervision by a dermatologist because the drug has many known side effects (many of which can be severe). About 25% of patients may relapse after one treatment. In those cases, a second treatment for another 4-6 months may be indicated to obtain desired results. It is often recommended that one lets a few months pass between the two treatments, because the condition can actually improve somewhat in the time after stopping the treatment and waiting a few months also gives the body a chance to recover. Occasionally a third or even a fourth course is used, but the benefits are often less substantial. The most common side effects are dry skin and occasional nosebleeds (secondary to dry nasal mucosa). Oral retinoids also often cause an initial flare up of acne within a month or so, which can be severe. There are reports that the drug has damaged the liver of patients. For this reason, it is recommended that patients have blood samples taken and examined before and during treatment. In some cases, treatment is terminated or reduced due to elevated liver enzymes in the blood, which might be related to liver damage. Others claim that the reports of permanent damage to the liver are unsubstantiated, and routine testing is considered unnecessary by some dermatologists. Blood triglycerides also need to be monitored. However, routine testing are part of the official guidelines for the use of the drug in many countries. Some press reports suggest that isotretinoin may cause depression but as of September 2005 there is no agreement in the medical literature as to the risk. The drug also causes birth defects if women become pregnant while taking it or take it while pregnant. For this reason, female patients are required to use two separate forms of birth control or vow abstinence while on the drug. Because of this, the drug is supposed to be given to females as a last resort after milder treatments have proven insufficient. Restrictive rules (see iPledge program) for use were put into force in the USA beginning in March 2006 to prevent misuse, causing occasioned widespread editorial comment.
Phototherapy.
Acne is most common in teenagers, but it can happen at any age, even as an infant. Three out of four teenagers have acne to some extent, probably caused by hormonal changes that stimulate oil production. However, people in their 30s and 40s may also have acne.Acne tends to run in families and can be triggered by:Hormonal changes related to menstrual periods, pregnancy, birth control pills, or stressGreasy or oily cosmetic and hair productsCertain drugs (such as steroids, testosterone, estrogen, and phenytoin)High levels of humidity and sweatingDespite the popular belief that chocolate, nuts, and other foods cause acne, this does not seem to be true.SymptomsBlackheads .Crusting of skin eruptions .Cysts .Inflammation around the skin eruptions .Pustules .Redness around the skin eruptions .Scarring of the skin .Whiteheads.Signs and tests
Your doctor can diagnose acne based on the appearance of the skin.
Treatments.
There are many products available for the treatment of acne, many of which are without any scientifically-proven effects. Generally speaking, successful treatments show little improvement within the first two weeks, instead taking a period of approximately three months to improve and start
flattening out. Many treatments that promise big improvements within two weeks are likely to be largely disappointing. However, short bursts of cortisone can give very quick results, and other treatments can rapidly improve some active spots, but usually not all active spots. Modes of improvement are not necessarily fully understood but in general treatments are believed to work in at least 4 different ways (with many of the best treatments providing multiple simultaneous effects):normalising shedding into the pore to prevent blockagekilling P. acnesanti-inflammatory effectshormonal manipulationA 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. There are a number of treatments that have been proven effective: 
Topical bactericidals
Widely available OTC bactericidal products containing benzoyl peroxide may be used in mild to moderate acne. The gel or cream containing benzoyl peroxide is rubbed, twice daily, into the pores over the affected region. Bar soaps or washes may also be used and vary from 2 to 10% in strength. In addition to its therapeutic effect as a keratolytic (a chemical that dissolves the keratin plugging the pores) benzoyl peroxide also prevents new lesions by killing P.acnes. In one study, roughly 70% of participants using a 10% benzoyl peroxide solution experienced a reduction in acne lesions after 6 weeks.Unlike antibiotics, benzoyl peroxide has the advantage of being a strong oxidizer (essentially a mild bleach) and thus does not appear to generate bacterial resistance. However, it routinely causes dryness, local irritation and redness. A sensible regimen may include the daily use of low-concentration (2.5%) benzoyl peroxide preparations, combined with suitable non-comedogenic moisturisers to help avoid overdrying the skin.Care must be taken when using benzoyl peroxide, as it can very easily bleach any fabric or hair it comes in contact with.Other antibacterials that have been used include triclosan, or chlorhexidine gluconate but these are often less effective, but also have fewer side-effects.Prescription-strength benzoyl peroxide preparations do not necessarily differ with regard to the maximum concentration of the active ingredient (10%), but the drug is made available dissolved in a
vehicle that more deeply penetrates the pores of the skin.Topical antibiotics
Externally applied antibiotics such as erythromycin, clindamycin, Stievamycin, or tetracycline aim to kill the bacteria that are harbored in the blocked follicles. While topical use of antibiotics is equally as effective as oral use, this method avoids possible side effects including upset stomach and drug interactions (e.g. it will not affect use of the oral contraceptive pill), but may prove awkward to apply over larger areas than just the face alone.
Oral antibiotics
Oral antibiotics used to treat acne include erythromycin or one of the tetracline antibiotics(tetracycline, the better absorbed oxytetracycline, or one of the once daily doxycycline, minocycline, or lymecycline). Trimethoprim is also sometimes used (off-label use in UK). However, reducing the P. acnes bacteria wi
ll not, in itself, do anything to reduce the oil secretion and abnormal cell behaviour that is the initial cause of the blocked follicles. Additionally the antibiotics are becoming less and less useful as resistant P. acnes are becoming more common. 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. Furthermore side effects of tetracycline antibiotics can include yellowing of the teeth and an imbalance of gut flora, so are only recommended after topical products have been ruled out.It has been found that sub-antimicrobial doses of antibiotics such as minocycline also improve acne. It is believed that minocycline's anti-inflammatory effect also prevents acne. These low doses do not kill bacteria and hence cannot induce resistance.Hormonal treatments
In females, acne can be improved with hormonal treatments. The common combined oestrogen/progestogen methods of hormonal contraception have some effect, but the antiandrogen, Cyproterone, in combination with an oestrogen (Diane 35) is particularly effective at reducing androgenic hormone levels. Diane-35 is not available in the USA, but a newer oral contraceptive containing the progestin drospirenone is now available with fewer side effects than Diane 35 / Dianette. Both can be used where blood tests show abnormally high levels of androgens, but are effective even when this is not the case. Along with this, treatment with low dose spironolactone can have anti-androgenetic properties, especially in patients with polycystic ovarian syndrome.If a pimple is large and/or does not seem to be affected by other treatments, a dermatologist may administer an injection of cortisone directly into it, which will usually reduce redness and inflammation almost immediately. This has the effect of flattening the pimple, thereby making it easier to cover up with makeup, and can also aid in the healing process. Side effects are minimal, but may include a temporary whitening of the skin around the injection point; and occasionally a small depression forms, which may persist, although often fills eventually. This method also carries a much smaller risk of scarring than surgical removal.
Tpical retinoids
A group of medications for normalizing the follicle cell lifecycle are topical retinoids such as tretinoin (brand name Retin-A), adapalene (brand name Differin), and tazarotene (brand name Tazorac). Like isotretinoin, they are related to vitamin A, but they are administered as topicals and generally have much milder side effects. They can, however, cause significant irritation of the skin. The retinoids appear to influence the cell creation and death lifecycle of cells in the follicle lining. This helps prevent the hyperkeratinization of these cells that can create a blockage. Retinol, a form of vitamin A, has similar but milder effects and is used in many over-the-counter moisturizers and other topical products. Effective topical retinoids have been in use over 30 years but are available only on prescription so are not as widely used as the other topical treatments. Topical retinoids often cause an initial flare up of acne and facial flushing.
Oral retinoids
inoidsdaily oral intake of vitamin A derivative isotretinoin (marketed as Accutane, Amnesteem, Sotret, Claravis) over a period of 4-6 months can cause long-term resolution or reduction of acne. It is believed that isotretinoin works primarily by reducing the secretion of oils from the glands, however some studies suggest that it affects other acne-related factors as well. Isotretinoin has been shown to be very effective in treating severe acne and can either improve or clear well over 80% of patients. The drug has a much longer effect than anti-bacterial treatments and will often cure acne for good. The treatment requires close medical supervision by a dermatologist because the drug has many known side effects (many of which can be severe). About 25% of patients may relapse after one treatment. In those cases, a second treatment for another 4-6 months may be indicated to obtain desired results. It is often recommended that one lets a few months pass between the two treatments, because the condition can actually improve somewhat in the time after stopping the treatment and waiting a few months also gives the body a chance to recover. Occasionally a third or even a fourth course is used, but the benefits are often less substantial. The most common side effects are dry skin and occasional nosebleeds (secondary to dry nasal mucosa). Oral retinoids also often cause an initial flare up of acne within a month or so, which can be severe. There are reports that the drug has damaged the liver of patients. For this reason, it is recommended that patients have blood samples taken and examined before and during treatment. In some cases, treatment is terminated or reduced due to elevated liver enzymes in the blood, which might be related to liver damage. Others claim that the reports of permanent damage to the liver are unsubstantiated, and routine testing is considered unnecessary by some dermatologists. Blood triglycerides also need to be monitored. However, routine testing are part of the official guidelines for the use of the drug in many countries. Some press reports suggest that isotretinoin may cause depression but as of September 2005 there is no agreement in the medical literature as to the risk. The drug also causes birth defects if women become pregnant while taking it or take it while pregnant. For this reason, female patients are required to use two separate forms of birth control or vow abstinence while on the drug. Because of this, the drug is supposed to be given to females as a last resort after milder treatments have proven insufficient. Restrictive rules (see iPledge program) for use were put into force in the USA beginning in March 2006 to prevent misuse, causing occasioned widespread editorial comment.
Phototherapy.
'Blue' and red light
It has long been known that short term improvement can be achieved with sunlight. However, studies have shown that sunlight worsens acne long-term[citation needed]. More recently, visible light has been successfully employed to treat acne (phototherapy) - in particular intense violet light (405-420nm) generated by purpose-built fluorescent lighting, dichroic bulbs, LEDs or lasers. Used twice weekly, this has been shown to reduce the number of acne lesions by about 64% and is even more effective when applied daily. The mechanism appears to be that a porphyrin (Coproporphyrin III) produced within P. acnes generates free radicals when irradiated by 420nm and shorter wavelengths of light.Particularly when applied over several days, these free radicals ultimately kill the bacteria.Since porphyrins are not otherwise present in skin, and no UV light is employed, it appears to be safe, and has been licensed by the U.S. FDA. The treatment apparently works even better if used with red visible light (660 nanometer) resulting in a 76% reduction of lesions after 3 months of daily treatment for 80% of the patients; and overall clearance was similar or better than benzoyl peroxide. Unlike most of the other treatments few if any negative side effects are typically experienced, and the development of bacterial resistance to the treatment seems very unlikely. After treatment, clearance can be longer lived than is typical with topical or oral antibiotic treatments; several months is not uncommon. The equipment or treatment, however, is relatively new and reasonably expensive to buy initially, although the total cost of ownership can be similar to many other treatment methods (such as the total cost of benzoyl peroxide, moisturiser, washes) over a couple of years of use.
