Acne Vulgaris

Acne vulgaris (commonly called acne) is a common skin condition, caused by changes in the pilosebaceous units, skin structures consisting of a hair follicle and its associated sebaceous gland via androgen stimulation. It is characterized by noninflammatory follicular papules or comedones and by inflammatory papules, pustules, and nodules in its more severe forms. Acne vulgaris affects the areas of skin with the densest population of sebaceous follicles; these areas include the face, the upper part of the chest, and the back. Severe acne is inflammatory, but acne can also manifest in noninflammatory forms. Acne lesions are commonly referred to as pimples, blemishes, spots, zits, or acne.

Acne is most common during adolescence, affecting more than 85% of teenagers, and frequently continues into adulthood. The cause in adolescence is generally an increase in male sex hormones, which people of both genders accrue during puberty. For most people, acne diminishes over time and tends to disappear—or at the very least decrease—after one reaches one's early twenties. There is, however, no way to predict how long it will take to disappear entirely, and some individuals will continue to suffer well into their thirties, forties and beyond.

Aside from scarring, its main effects are psychological, such as reduced self-esteem and, according to at least one study, depression or suicide. Acne usually appears during adolescence, when people already tend to be most socially insecure. Early and aggressive treatment is therefore advocated by some to lessen the overall impact to individuals.

Terminology
Different types of Acne Vulgaris: A: Cystic acne on the face, B: Subsiding tropical acne of trunk, C: Extensive acne on chest and shoulders.

The term acne comes from a corruption of the Greek άκμή (acne in the sense of a skin eruption) in the writings of Aëtius Amidenus. Used by itself, the term "acne" refers to the presence of pustules and papules. The most common form of acne is known as "acne vulgaris", meaning "common acne". Many teenagers get this type of acne. Use of the term "acne vulgaris" implies the presence of comedones.

Causes of acne

Acne develops as a result of blockages in follicles. Hyperkeratinization and formation of a plug of keratin and sebum (a microcomedo) is the earliest change. Enlargement of sebaceous glands and an increase in sebum production occur with increased androgen (DHEA-S) production at adrenarche. The microcomedo may enlarge to form an open comedo (blackhead) or closed comedo (whitehead). Whiteheads are the direct result of skin pores becoming clogged with sebum, a naturally occurring oil, and dead skin cells. In these conditions the naturally occurring largely commensal bacteria Propionibacterium acnes can cause inflammation, leading to inflammatory lesions (papules, infected pustules, or nodules) in the dermis around the microcomedo or comedo, which results in redness and may result in scarring or hyperpigmentation.

Causes of acne

Primary causes

The root causes of why some people get acne and some do not are not fully known. It is known to be partly hereditary. Several factors are known to be linked to acne:

* Family/Genetic history. The tendency to develop acne runs in families. For example, school-age boys with acne often have other members in their family with acne as well. A family history of acne is associated with an earlier occurrence of acne and an increased number of retentional acne lesions.
* Hormonal activity, such as menstrual cycles and puberty. During puberty, an increase in male sex hormones called androgens cause the follicular glands to get larger and make more sebum.
* Inflammation, skin irritation or scratching of any sort will activate inflammation. Anti-inflammatories are known to improve acne.
* Stress, through increased output of hormones from the adrenal (stress) glands[citation needed]. While the connection between acne and stress has been debated, scientific research indicates that “increased acne severity” is “significantly associated with increased stress levels.” The National Institutes of Health list stress as a factor that “can cause an acne flare.” A study of adolescents in Singapore “observed a statistically significant positive correlation…between stress levels and severity of acne.”
* Hyperactive sebaceous glands, secondary to the three hormone sources above.
* Accumulation of dead skin cells that block or cover pores[citation needed].
* Bacteria in the pores. Propionibacterium acnes (P. acnes) is the anaerobic bacterium that causes acne. In-vitro resistance of P. acnes to commonly used antibiotics has been increasing.
* Use of anabolic steroids.
* Any medication containing lithium, barbiturates or androgens.
* Exposure to certain chemical compounds. Chloracne is particularly linked to toxic exposure to dioxins, namely Chlorinated dioxins[citation needed].
* Exposure to halogens. Halogen acne is linked to exposure to halogens (e.g. iodides, chlorides, bromides, fluorides)[citation needed].
* Chronic use of amphetamines or other similar drugs.

Several hormones have been linked to acne: the androgens 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].

Development of acne vulgaris in later years is uncommon, although this is the age group for Rosacea which may have similar appearances. True acne vulgaris in adult women may be a feature of an underlying condition such as pregnancy and disorders such as polycystic ovary syndrome or the rare Cushing's syndrome. Menopause-associated acne occurs as production of the natural anti-acne ovarian hormone estradiol fails at menopause. The lack of estradiol also causes thinning hair, hot flashes, thin skin, wrinkles, vaginal dryness, and predisposes to osteopenia and osteoporosis as well as triggering acne (known as acne climacterica in this situation).

Diet

Chocolate

The popular belief that consumption of chocolate can cause acne is not supported by scientific studies.

Milk

Recently, three epidemiological studies from the same group of scientists found an association between acne and consumption of partially skimmed milk, instant breakfast drink, sherbet, cottage cheese, and cream cheese. The researchers hypothesize that the association may be caused by hormones (such as several sex hormones and bovine insulin-like growth factor 1 (IGF-1)) or even iodine present in cow milk.

Carbohydrates

The recent low glycemic-load hypothesis postulates that rapidly digested carbohydrate foods (such as soft drinks, sweets, white bread) produce an overload in blood glucose (hyperglycemia) that stimulates the secretion of insulin, which in turn triggers the release of IGF-1.[26] IGF-1 has direct effects on the pilosebaceous unit (and insulin at high concentrations can also bind to the IGF-1 receptor) and has been shown to stimulate hyperkeratosis and epidermal hyperplasia. These events facilitate acne formation. Sugar consumption might also influence the activity of androgens via a decrease in sex hormone-binding globulin concentration.

Further research is necessary to establish whether a reduced consumption of high-glycemic foods, or treatment that results in increased insulin sensitivity (like metformin) can significantly alleviate acne, though consumption of high-glycemic foods should in any case be kept to a minimum, for general health reasons. Avoidance of "junk food" with its high fat and sugar content is also recommended.

Vitamins A and E

Studies have shown that newly diagnosed acne patients tend to have lower levels of vitamin A circulating in their bloodstream than those who are acne free.[43] In addition people with severe acne also tend to have lower blood levels of vitamin E.

Hygiene

Acne is not caused by dirt. This misconception probably comes from the fact that blackheads look like dirt stuck in the openings of pores. The black color is not dirt but simply oxidised 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. Built-up oil of the skin can block the passages of these pores, so standard washing of the face could wash off old oil and help unblock the pores.

Treatments

Available 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.[citation needed] 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 blockage
* killing Propionibacterium acnes
* anti-inflammatory effects
* hormonal manipulation

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. There are a number of treatments that have been proven effective:

Topical bactericidals

Other antibacterials that have been used include triclosan, or chlorhexidine gluconate. Though these treatments are often less effective, they also have fewer side-effects.

Topical antibiotics

Externally applied antibiotics such as erythromycin, clindamycin, stievamycin, or tetracycline 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

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 is particularly effective at reducing androgenic hormone levels. Both can be used where blood tests show abnormally high levels of androgens, but are effective even when this is not the case.

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.

Topical retinoids

Oral retinoids
: isotretinoin

Phototherapy

'Blue' and red light

It has long been known that short term improvement can be achieved with light. Recently, visible light has been successfully employed to treat acne (phototherapy or deep penetrating light therapy) - in particular intense violet light (405-420 nm) 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 420 nm and shorter wavelengths of light.[48] 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 a mixture of the violet light and 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, moisturizer, washes) over a couple of years of use.

Photodynamic therapy

Laser treatment

Laser surgery has been in use for some time to reduce the scars left behind by acne, but research has been done on lasers for prevention of acne formation itself. The laser is used to produce one of the following effects:

* to burn away the follicle sac from which the hair grows
* to burn away the sebaceous gland which produces the oil
* to induce formation of oxygen in the bacteria, killing them

Since lasers and intense pulsed light sources cause thermal damage to the skin, there are concerns that laser or intense pulsed light treatments for acne will induce hyperpigmented macules (spots) or cause long-term dryness of the skin.

Less widely used treatments

* Aloe vera: there are treatments for acne mentioned in Ayurveda using herbs such as Aloe vera, Neem, Haldi (Turmeric) and Papaya. There is limited evidence from medical studies on some of these products, although others have been proven effective. Products from Rubia cordifolia, Curcuma longa (commonly known as Turmeric), Hemidesmus indicus (known as ananthamoola or anantmula), and Azadirachta indica (Neem) have been shown to have anti-inflammatory effects, but not aloe vera.
* Azelaic acid (brand names Azelex, Finevin and Skinoren) is suitable for mild, comedonal acne.
* Calendula used in suspension is used as an anti-inflammatory agent
* Cortisone injection into spots, also cortisone pills are sometimes used
* Heat: local heating may be used to kill the bacteria in a developing pimple and so speed healing.
* Naproxen or ibuprofen are used for some moderate acne for their anti-inflammatory effect.
* Nicotinamide, (Vitamin B3) used topically in the form of a gel, has been shown in a 1995 study to be of comparable efficacy to topical clindamycin topical antibiotic used for comparison.[62] Topical nicotinamide is available both on prescription and over-the-counter. The property of topical nicotinamide's benefit in treating acne seems to be its anti-inflammatory nature. It is also purported to result in increased synthesis of collagen, keratin, involucrin and flaggrin and may also according to a cosmetic company be useful for reducing skin hyperpigmentation (acne scars), increased skin moisture and reducing fine wrinkles.
* Tea tree oil (melaleuca oil) dissolved in a carrier (5% strength) has been used with some success, where it is comparable to benzoyl peroxide but without excessive drying, kills P. acnes, and has been shown to be an effective anti-inflammatory in skin infections.
* Rofecoxib was shown to improve premenstrual acne vulgaris in a placebo controlled study.
* Zinc: Orally administered zinc gluconate has been shown to be effective in the treatment of inflammatory acne, although less so than tetracyclines.
* Comedo extraction
* Pantothenic acid, (high dosage Vitamin B5)
* Detoxification is a common method used by alternative medicine practitioners for the treatment of acne, although there have been no studies to prove its success. Detoxification is the process of cleansing the body of toxins commonly caused by the environment, pharmaceutical drugs, food, and cosmetics.