Melasma treatments - from frustration to fruition?

Eilat, Israel - For the last 50 years, hydroquinone has been the reference of treatment in hyperpigmentations, and more recently, combination formulas, peelings and adjuvant therapies including sunscreens containing the drug, show promise. However, topical agents have yet to prove a constant and uncontested efficiency, said Daphne Thioly-Bensoussan M.D., during the 28^th Annual Meeting of the Israeli Conference of Dermatology and Venerology.

Dr. Thioly-Bensoussan admits that, "Even today in patients with fair or brown skin, melasmas pose a difficult therapeutic problem, not to mention the significant psychological distress and sometimes elusive social acceptance all affecting their quality of life. Therapy success depends on the pigment distribution in the epidermis (70 percent), dermis (15 percent) and mixed (20 percent), the efficiency and tolerance of topical treatments and the associated peelings, strict photoprotection understanding by the patient, patient compliance to slow and indefinite treatment and, of course, the risk of post inflammatory hyperpigmentation."

According to a June 20^th , 2001 European directive, hydroquinone cannot be part of OTC products - compelling pharmaceutical companies to find new, effective molecules to be applied alone or associated with cosmetic creams. Hydroquinone is employed under prudent medical responsibility in compound formulas with different concentrations adapted to tolerance, says Dr. Thioly-Bensoussan.

"The tretinoin reduces the atrophic effects of the steroids as well as facilitates the epidermal penetration of hydroquinone. The steroids, in turn, help reduce the irritation caused by tretinoin. The tolerance and efficiency won by this synergistic-like effect allows an increase in the hydroquinone percentage and lowering of the tretinoin percentage. Finally, ascorbic acid 0.1 percent (an antioxidant) helps keep the formula stable," says Dr. Thioly-Bensoussan. She adds that a variety of formulations with dexamethasone, betamethasone valerate or triamcinolone acetonide can be employed.

Peelings are also widely employed, but due to the risk of reactional hyperpigmentation, Dr. Thioly-Bensoussan suggests only light superficial and medium superficial peels be used.

Superficial peels remove the stratum corneum and increase the penetration of bleaching agents. Here, Dr. Thioly-Bensoussan successfully uses a glycolic peel (Neostrata) 20 to 70 percent (a total of eight peels every three weeks with at least four peels at 70 percent), Jessner peel (14 percent resorcinol, 14 percent salicylic acid and 14 percent lactic acid - once a month), trichloroacetic acid (TCA) peels (under 30 percent) or salicylic peels (two peels at 20 percent or three peels at 30 percent).

Deeper peels can penetrate deep enough to remove epidermal and dermal pigmentation, but the risk of post-inflammatory hyperpigmentation is very real. If a deeper peel is to be undertaken, Dr. Thioly-Bensoussan suggests a medium depth peel using TCA 30 to 35 percent, TCA combined with Jessner or alpha hydroxy acids (AHA) 70 percent, a Krulig peel or a weekend peel.

Dr. Thioly-Bensoussan emphasizes the importance of both choosing a peeling that is tailored to the clinical picture and making sure the patient is fully aware of and accepts the possible adverse effects and their social repercussions, especially when a deeper peel is used. Here, the risk of post-inflammatory hyperpigmentation is significant, thereby possibly necessitating a retreatment.

Sunscreens are critical for long-term success and should be used repeatedly - all day, everyday and indefinitely. SPF 30 and higher, UVA and UVB filters and mineral blocks (titanium or zinc dioxide) are recommended. Dr. Thioly-Bensoussan suggests applying two layers of a waterproof or sweat-proof formula one hour before sun exposure and re-applying it every two hours, as well as wearing a hat and sunglasses.

Dr. Thioly-Bensoussan refrains from using lasers in melasma because of the mechanical trauma they induce on the skin. Thermal injury, melanocyte stimulation, as well as prolonged inflammatory stimulation of melanocytes all lead to unsatisfactory results.