MedEsthetics magazines offers business education and in-depth coverage of the latest noninvasive cosmetic procedures for physicians and practice managers working in the medical aesthetics industry.
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46 APRIL 2014 | Med Esthetics importance of regular sunscreen use, and the evidence of its role in preventing long-term skin damage and photoaging continues to grow. "About 90% of the wrinkles that occur on our faces, especially in lighter skin types, are related to UV exposure," says Dr. Palm. There are a myriad of studies supporting the use of sunscreen. One of the most recent appeared in the Annals of Internal Medi- cine (June 4, 2013). "This was a 15-year study from Australia that showed that people who used sunscreen regularly actually showed a marked decrease in photoaging of the skin," says Dr. Palm. In more recent years, sun- screen formulations have evolved as we have gained a better understanding of the full spectrum of damaging UV rays that affect skin health. "You must protect against UVA," says Kulesza. "When you can start to see the sun- screen on the skin, that means you're protecting against the longest, most penetrating wavelengths of UV (closest to visible light), and that's good." In February 2014, a study of 68 melasma patients appeared in the journal of Photodermatology, Photoim- munology & Photomedicine. The patients, all of whom were using a 4% hydroquinone product, were random- ized into one of two groups. Group one used a regular UV-only broad-spectrum sunscreen. Group two used a broad-spectrum sunscreen with iron oxide as a visible light (VL)-absorbing pigment. The researchers found that, at eight weeks, group two showed "15%, 28% and 4% greater improvements than the UV-only group in MASI scores, colorimetric values and melanin assess- ments, respectively." HYDROQUINONE The second product on our list that is FDA-approved, hydroquinone, has been shrouded in controversy for several years. But among the dermatologic community, it remains the gold standard for hyperpigmentation. "Hydroquinone is still one of the cornerstones of what I use in my practice," says Dr. Palm. "It is the gold standard to which other brightening agents are compared if there is a head-to-head comparison, and I think it is hard to rival the effects that you see with hydroquinone." The overwhelming advantage of hydroquinone, says Kulesza, is its unique molecular structure. "It consists of a ring of six carbon atoms. The melanocyte—which is the cell that makes pigment—seems to have a little substrate, or 'platform' inside the cell where it makes melanin," he says. "The melanocyte normally takes in tyrosine, which also incorporates a six carbon ring, and adds different atoms to that molecule to turn it into melanin. Due to its structural similarity, hydroquinone seems to be able to 'fool' the melanocyte into thinking that it's working with tyrosine. This is called competitive antagonism. It can work night and day, but it cannot make any melanin out of that hydroquinone molecule." Structurally, its carbon ring makes hydroquinone similar to phenol and benzene. "The structural similarity of hydro- quinone to phenol and benzene, both toxic compounds, teaches us that we must use this compound with great care; it is a medicine," says Kulesza. In 2006, when the FDA moved to restrict the sale of hydroquinone in the United States based on concerns relating to its potential toxic affects, pharmaceutical com- panies spent millions of dollars researching its safety. Their results helped stay further regulatory action. "When used in accordance with FDA-approved label directions, hydroquinone appears to be both safe and effective," says Kulesza. "Similarly, when you take two aspirin tablets as directed, it's safe and effective to treat a headache. If I take 60 aspirin tablets, I will end up in the hospital. The key words here are 'as directed.'" HYDROXY ACIDS Chemical peels have long been a staple of spas and dermatology practices, and with good reason. Alpha- and beta-hydroxy acids, including lactic, glycolic and salicylic acids, have a strong track record in rejuvenating photo- damaged skin. "They do not have as profound a range of biological effects in the skin as retinoids, because they do not penetrate deeply into the skin or into the nucleus of the cell," says Kulesza, "They act more superfi cially and a little more indirectly." The best understood mechanism of action behind these acids is that they create infl ammation that sends signals to the cells to stimulate the production of collagen BEYOND THE HYPE A recent, 15-year study showed that individuals who regularly used sunscreen had a marked decrease in photoaging of the skin. "Hydroquinone is the gold standard to which other brightening agents are compared if there is a head-to-head comparison." © THINKSTOCK B e y o n d H y p e M E D 4 1 4 . i n d d 4 6 Beyond Hype MED414.indd 46 3 / 1 3 / 1 4 9 : 2 1 A M 3/13/14 9:21 AM