Even with all the products manufactured, they all still use several basic ingredients, all of which work to a degree. As you"ll read further down, some have side effects, and some work better for some skin types that others. Your best source of information however, would be a dermatologist, who can examine your skin and help you select the best product for you. We collected quite a few info from different sites that explain the different products; pros and cons. Please check each link for complete information.

When it comes to selecting treatment for these areas, one factor to consider is the depth of the discolored pigment. Most of the time discoloration is superficial. In a few cases, the discoloration lies deep in the dermis. If the pigment is in the epidermis, it can be helped with skin-lightening products. If the pigment is deeper, laser treatments are a consideration. For topical treatments, according to an article in The American Journal of Clinical Dermatology.
SOURCE: (September-October 2000, pages 261-268)

Topical hydroquinone 2 to 4% alone or in combination with tretinoin 0.05 to 0.1% is an established treatment. Topical azelaic acid 15 to 20% can be as efficacious as hydroquinone. Tretinoin is especially useful in treating hyperpigmentation of photoaged skin. Kojic acid, alone or in combination with glycolic acid or hydroquinone, has shown good results, due to its inhibitory action on tyrosinase. Chemical peels are [also] useful to treat melasma."

Among skin-lightening agents, hydroquinone (HQ) is one of the most widely prescribed agents in the world. However, with reports of potential mutagenicity and epidemics of ochronosis in African nations, there has been increasing impetus to find alternative herbal and pharmaceutical depigmenting agents. A review of the literature reveals that numerous other depigmenting or skin-lightening agents are in use or in investigational stages. Some of these, such as kojic and azelaic acid, are well known to most dermatologists. Others more recently have been discovered and reported in the literature.

The 2% HQ is readily available over-the-counter in various cosmetic preparations. However, for better efficacy, it often is compounded into various mixtures for treatment of hyperpigmentation. The original Kligman formula involves compounding 5% HQ with 0.1% retinoic acid and 0.1% dexamethasone in a hydrophilic ointment base. Concentrations as high as 10% can be compounded extemporaneously for refractory cases. Evidence of improvement with HQ (monotherapy) usually is observed at 4-6 weeks, with improvement appearing to plateau at about 4 months. Despite its remarkable overall safety, the physician ought to bear in mind the potential adverse effects. Contact dermatitis occurs in a small number of patients and responds promptly to topical steroids. An uncommon, yet important, adverse effect of HQ is exogenous ochronosis. This disorder is characterized by progressive darkening of the area to which the cream containing HQ is applied. Histologically, degeneration of collagen and elastic fibers occurs. This degeneration is followed by the appearance of characteristic ochronotic deposits consisting of crescent-shaped, ochre-colored fibers in the dermis.

Skin-whitening products work in various ways. Some contain acids that remove old skin to reveal newer, lighter skin underneath. Others inhibit melanin, like those with mulberry extract, licorice extract, kojic acid, arbutin and hydroquinone, an ingredient in prescription creams for blemishes as well as in photo processing materials. Some of the most effective agents are also risky and are often the least expensive, like mercury-based ingredients or hydroquinone, which in Thailand sells for about $20 per kilogram (2.2 pounds), compared with highly concentrated licorice extract, which sells for about $20,000 per kilogram. 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.

No comments:

Post a Comment