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Skin whitening

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Skin whitening, skin lightening and skin bleaching refers to the practice of using chemical substances in an attempt to lighten skin tone or provide an even skin complexion by lessen the concentration of melanin. Several chemical has been shown to be effective in skin whitening.

Uses

Specific zones of abnormally high pigmentation such as moles and birthmarks may be depigmented to match to the surrounding skin. Conversely, in cases of vitiligo, unaffected skin may be lightened to achieve a more uniform appearance.[1] However, in cases where these spot treatment creams are used in attempt to lighten the entire complexion, all of the current methods are considered ineffective. Complete skin depigmentation is simply a futile process. An additional application is genital or anal bleaching, intended to reduce the typically darker pigmentation of the genital and perianal area.

Long term use of skin whiteners can lead to pigmentation increasing to the joints of the fingers, toes, buttocks and ears. The skin of the face can become thinned and the area around the eyes can have increased pigmentation causing a 'bleach panda effect'.[2]

Combination treatments

Most skin-lightening treatments, which can reduce or block some amount of melanin production, are aimed at inhibiting tyrosinase. Many treatments use a combination of topical lotions or gels containing melanin-inhibiting ingredients along with a sunscreen, and a prescription retinoid. Depending on how the skin responds to these treatments, exfoliants — either in the form of topical cosmetic or chemical peels — and lasers may be used. New development using LED systems are also showing good results.[3]

Home made treatments

Many[quantify] people the world over[weasel words] use home made treatments for a whiter skin, rather than buy commercial skin lighteners.[citation needed] These home made treatments include extracts of lemon juice, milk, lime, licorice and other herbs.[4][unreliable source?]

Mercury

Many skin whiteners contain toxic mercury such as mercury(II) chloride or ammoniated mercury as the active ingredient. However mercury has been banned in most countries (Europe 1976)(USA 1990) for use in skin whitening because it accumulates on skin and it can have the opposite results in the long term. Some studies suggest that long-term use could cause systemic absorption that leads to tissue accumulation of the substance.[5]

Hydroquinone

Main article: Hydroquinone

In medical literature, hydroquinone is considered the primary topical ingredient for inhibiting melanin production.[6] Its components have potent antioxidant abilities.[7] Topical hydroquinone comes in 2% (available in cosmetics) to 4% (or more) concentrations (available from a physician or by prescription), alone or in combination with tretinoin 0.05% to 0.1%. Research has shown hydroquinone and tretinoin to prevent sun- or hormone-induced melasma.[8]

Hydroquinone is a strong inhibitor of melanin production, meaning that it prevents skin from making the substance responsible for skin color.[9] Hydroquinone does not bleach the skin but lightens it, and can only disrupt the synthesis and production of melanin hyperpigmentation. It has been banned in some countries (e.g. France) because of fears of a cancer risk.

Some concerns about hydroquinone's safety on skin have been expressed, but the research when it comes to topical application indicates negative reactions are minor or a result of using extremely high concentrations or from other skin-lightening agents such as glucocorticoids or mercury iodine. This is particularly true in Africa where adulterated skin lightening products are commonplace.[10] Hydroquinone has been shown to cause leukemia in mice and other animals. The European Union banned it from cosmetics in 2001, but it shows up in bootleg creams in the developing world. It is sold in the United States as an over-the-counter drug, but with a concentration of hydroquinone not exceeding 2 percent. [11]

Because of hydroquinone's action on the skin, it can be irritant, particularly in higher concentrations of 4% or greater and predictably when combined with tretinoin. Some medications have been created that combine 4% hydroquinone with tretinoin and a form of cortisone. The cortisone is included as an anti-inflammatory. The negative side effect of repeated application of cortisone is countered by the positive effect of the tretinoin so that it does not cause thinning of skin and damage to collagen.[12] Safer alternatives are more expensive but are available.

Alternatives to hydroquinone

Some of alternative lighteners are natural sources of hydroquinone. They include Mitracarpus scaber extract, Uva ursi (bearberry) extract, Morus bombycis (mulberry), Morus alba (white mulberry), and Broussonetia papyrifera (paper mulberry). All of these contain arbutin (technically known as hydroquinone-beta-D-glucoside), which can inhibit melanin production. Pure forms of arbutin are considered more potent for affecting skin lightening (alpha-arbutin, beta-arbutin, and deoxy-arbutin). Beta-Arbutin is also known by its more common name of Bearberry extract

Some research has shown topical azelaic acid in 15% to 20% concentrations to be as efficacious as hydroquinone with a decreased risk of irritation. Tretinoin by itself has also been shown to be useful in treating hyperpigmentation of sun-damaged skin. Kojic acid, alone or in combination with glycolic acid or hydroquinone, also has shown good results due to its inhibitory action on tyrosinase (though kojic acid has had problems in terms of stability and potential negative effects on the skin and is rarely used today). Several plant extracts and vitamin C also have some research showing them to be effective for inhibiting melanin production.[13]

Niacinamide is claimed to be a much safer alternative when applied topically for skin or genitalia whitening.[citation needed] According to a cosmetic company, it has no adverse side-effects and as well as acne reduction, also increases skin moisture and reduces fine wrinkles. [14]

Other options with some amount of research regarding their potential skin lightening abilities are licorice extract (specifically glabridin), azelaic acid, and stabilized vitamin C (L-ascorbic acid, ascorbic acid, and magnesium ascorbyl phosphate).

There is also a small amount of research showing oral supplements of pomegranate extract, ellagic acid, vitamin E, and ferulic acid can inhibit melanin production.[15]

Arbutin

Arbutin is derived from the leaves of bearberry, cranberry, mulberry or blueberry shrubs, and also is present in most types of pears. It can have melanin-inhibiting properties.[16] Arbutin and other plant extracts are considered safe alternatives to commonly used depigmenting agents to make the skin fairer. Medical studies have shown the efficiency of Arbutin for skin lightening.[17] There are patents controlling its use for skin lightening.

Tretinoin

Research has shown that the use of Tretinoin (also known as all-trans retinoic acid) can only be somewhat effective in treating skin discolorations.[18]

Users of tretinoin have to avoid sunlight, as the skin can tan. Using tretinoin makes the skin more sensitive to UVA and UVB rays.

Alpha hydroxy acids

Alpha hydroxy acids (AHAs) — primarily in the form of lactic acid and glycolic acid — are the most researched forms of AHAs because they have a molecular size that allows effective penetration into the top layers of skin. It is generally assumed that in and of themselves AHAs in concentrations of 4% to 15% are not effective for inhibiting melanin production and will not lighten skin discolorations in that manner. It is believed that their benefit is in helping cell turnover rates and removing unhealthy or abnormal layers of superficial skin cells (exfoliation) where hyperpigmented cells can accumulate. However, other research has shown that lactic and glycolic acids can indeed inhibit melanin production separate from their actions as an exfoliant on skin.[19]

Alpha hydroxy acid peels (using 50% concentrations or greater) may remove skin discolorations. Only a qualified physician should perform these types of facial peels.[20]

Kojic acid

Kojic acid is a by-product in the fermentation process of malting rice for use in the manufacturing of sake, the Japanese rice wine. Some research shows kojic acid to be effective for inhibiting melanin production.[21] However, kojic acid is an unstable ingredient in cosmetic formulations. Upon exposure to air or sunlight it can turn brown and lose its efficacy. Many cosmetic companies use kojic dipalmitate as an alternative because it is more stable in formulations. However, there is no research showing kojic dipalmitate to be as effective as kojic acid, although is it a good antioxidant. Further, some controversial research has suggested that kojic acid may have carcinogenic properties in large doses. [1] [22] Other further studies show that kojic acid is not carcinogenic,but can cause allergies and skin irritation.

Azelaic acid

Azelaic acid is a component of grains, such as wheat, rye, and barley. It is applied topically in a cream formulation at a 20% concentration. Azelaic acid is used to treat acne, but there also is research showing it to be effective for skin discolorations.[23] Other research also indicates azelaic acid may be an option for inhibiting melanin production.[24]

Vitamin C

Magnesium ascorbyl phosphate, L-ascorbic acid, ascorbyl glucosamine, and ascorbic acid are various forms of vitamin C considered stable and effective antioxidants for skin.[citation needed] There are very few studies showing them to have benefit for inhibiting melanin production. The concentrations of these ingredients used in tests were generally high (more than 5%), which is rarely used in cosmetic formulations.[25] Vitamin C can help brighten the skin tone.

Depigmenting agents

Most commonly, depigmentation of the skin is linked to people born with vitiligo, which produces differing areas of light and dark skin. These individuals, if they so decided to use a lightening process to even out their skin tone, could apply a topical cream containing the organic compound monobenzone to lessen the remaining pigment. Monobenzone may cause destruction of melanocytes and permanent depigmentation. An alternate method of lightening is to use the chemical mequinol over an extended period of time. Increasingly, people who are not afflicted with the vitiligo experiment with lower concentrations of monobenzone creams in the hope of lightening their skin tone evenly. However, monobenzone is not recommended for skin conditions other than vitiligo.

Laser treatments

Both ablative and nonablative lasers can have a profound effect on melasma[citation needed]. However, the results are not always consistent, and problems have been reported (such as hypo- or hyperpigmentation). Laser treatments of this kind are more likely to result in problems for those with darker skin tones.[26]

Cryosurgery

Another alternative to laser treatment is cryosurgery using liquid nitrogen. Controlled destruction of skin cells causes the skin to naturally regenerate itself. Excess melanin comes to the surface and peels off in a few days. This is particularly useful in sensitive areas like the genitals where laser treatment could leave a scar. Efficacy of the treatment depends on the depth of the pigment. Freckles in any part of the body can be treated the same way.[citation needed]

Controversy

In recent years the practice of skin lightening has come under fire because of its potential negative health effects and association with colonialism and self-imagery. There is evidence to suggest that some types of skin-whitening products use active ingredients (such as mercurous chloride) and hydroquinone which can be harmful.[27] Hydroquinone has now been banned in Europe and in many other countries can only be prescribed by a doctor for certain skin conditions.

There is a growing market in skin lightening products that are toxic-free. However, they are more costly due their expensive ingredients. Japan and the Pacific is a big market for high quality skin lightening products imported from Europe.[28] In India, Fair and Lovely by Unilever remains a popular brand despite the company being forced to withdraw television advertisements for the product in 2007.

In developing countries, banned chemicals are still being used in skin lightening creams. [citation needed]

See also

References

  1. ^ Rashid, Aliya, A rush to cream the fairness fetish, Dai
  2. ^ Olumide, Y. M. (2010). "Use of skin lightening creams". BMJ. 341 (nov23 2): c6102–c6102. doi:10.1136/bmj.c6102. ISSN 0959-8138.
  3. ^ Journal of the American Academy of Dermatology, May 2006, supplemental, pages 272-281; Dermatologic Surgery, March 2006, pages 365-371; Journal of Drugs in Dermatology, September–October 2004, supplemental, 27-34; International Journal of Dermatology, December 2003, pages 966-972; and Archives of Dermatology, December 2002, pages 1578-1582).
  4. ^ A Step By Step In Preaparing A Home-Made Skin Lightening Cream
  5. ^ "Skin lightening products".
  6. ^ Cutis, March 2006, pages 177-184; Journal of Drugs in Dermatology, September–October 2005, pages 592-597; Journal of Cosmetic Science, May–June 1998, pages 208-290; Dermatological Surgery, May 1996, pages 443-447.
  7. ^ Journal of Natural Products, November 2002, pages 1 605-1611.
  8. ^ Dermatologic Surgery, March 2006, pages 365-371.
  9. ^ Journal of Dermatological Science, August, 2001, supplemental, pages 68-75.
  10. ^ British Journal of Dermatology, March 2003, pages 493-500 and Critical Reviews in Toxicology, May 1999, pages 283-330.
  11. ^ Fuller, Thomas (2006-05-14). "A Vision of Pale Beauty Carries Risks for Asia's Women". The New York Times. Retrieved 2010-05-23.
  12. ^ Drugs in Dermatology, July–August 2004, pages 377-381.
  13. ^ Journal of the American Academy of Dermatology, May 2006, pages S272-S281; International Journal of Dermatology, August 2004, pages 604-607; and The American Journal of Clinical Dermatology, September–October 2000, pages 261-268).
  14. ^ Procter & Gamble. "Skin lightening products" (PDF).
  15. ^ Experimental Dermatology, August 2005, pages 601-608; Bioscience, Biotechnology, and Biochemistry, December 2005, pages 2368-2373; International Journal of Dermatology, August 2004, pages 604-607; Journal of Drugs in Dermatology, July–August 2004, pages 377-381; Facial and Plastic Surgery, February 2004, pages 3-9; Dermatologic Surgery, March 2004, pages 385-388; Journal of Bioscience and Bioengineering, March 2005, pages 272-276; Journal of Biological Chemistry, November 7, 2003, pages 44320-44325; Journal of Agriculture and Food Chemistry, February 2003, pages 1201-1207; International Journal of Cosmetic Science, August 2000, pages 291-303; and Anti-Cancer Research, September–October 1999, pages 3769-3774).
  16. ^ The Journal of Pharmacology and Experimental Therapeutics, February 1996, pages 765-769.
  17. ^ Inhibitory effects of arbutin....© Springer Science+Business Media B.V. 2007- 10.1007/s10529-007-9605-1- Dr Jaeho Cha
  18. ^ Dermatologic Surgery, March 2006, pages 365-371; Acta Dermato-Venereologica, July 1999, pages 305-310; International Journal of Dermatology, April 1998, pages 286-292; and Journal of the American Academy of Dermatology, March 1997, pages S27-S36.
  19. ^ Experimental Dermatology, January 2003, supplemental. pages 43-50.
  20. ^ Dermatologic Surgery, February 2005, pages 149-154; Journal of Cutaneous Medicine and Surgery, April 2004, pages 97-102; Cutis, February 2004, supplemental, pages 18-24; Dermatologic Therapy, June 2004, pages 196-205; and Dermatological Surgery, June 1999, pages 450-454.
  21. ^ Archives of Pharmacal Research, August 2001, pages 307-311.
  22. ^ Mutation Research, Genetic Toxicology and Environmental Mutagenesis, June 2005, pages 133-1450 and Toxicological Sciences, September 2004, pages 43-49.
  23. ^ International Journal of Dermatology, December 1991, pages 893-895.
  24. ^ Journal of the American Academy of Dermatology, May 2006, supplemental, pages 272-281.
  25. ^ International Journal of Dermatology, August 2004, page 604; Dermatology, April 2003, pages 316-320; Journal of the American Academy of Dermatology, January 1996, pages 29-33;
  26. ^ Journal of the American Academy of Dermatology, May 2006, supplemental, pages 262-271; Dermatologic Therapy, January 2001, page 46; Journal of Cosmetic and Laser Therapy, March 2005, pages 39-43; Journal of Cutaneous Medicine and Surgery, April 2004, pages 97-102; Journal of Drugs in Dermatology, November–December 2005, pages 770-774; Dermatologic Surgery, October 2005, page 1263; and Lasers in Surgery and Medicine, April 2000, pages 376-379.
  27. ^ Counter, S. Allen, Whitening skin can be deadly, Boston Globe, 16 Dec 2003
  28. ^ Global Industry Analysts (GIA) Skin lighteners: a global strategic business report’ 2009
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