Optimal management of melasma in Hispanic women involves multimodal therapy carefully balanced in terms of concentration and duration to maximize improvement in pigmentation and minimize adverse effects that can exacerbate the condition, Miguel R. Sanchez, M.D., said at the annual meeting of the American Academy of Dermatology.

To treat this common, chronic, and what may patients consider to be disfiguring skin disorder, he begins with a regimen combining daily use of hydroquinone, tretinoin (Retin-A), and a topical corticosteroid with periodic glycolic acid peels. Dr. Sanchez said he generally initiates hydoquinone by prescribing the 4-percent preparation. Then, depending on the patients response and ability to tolerate the treatment, he will increase the concentration up to 10 percent in some cases, although this high strength is associated with an increased risk of ochronosis.

"The results of some published studies would suggest there is no benefit for using hydroquinone at a concentration higher than 2 percent. However, I believe there were some flaws in those studies and my personal experience as well as that of other dermatologists would indicate otherwise," said Dr. Sanchez, associate professor of dermatology, New York University Medical Center, New York.

A response to hydroquinone should be noted within six weeks of beginning treatment, and the peak bleaching effect occurs after six months. More prolonged use may lead to paradoxical pigmentation as well as increased risk of ochronosis. For those reasons, he uses hydroquinone in a cyclical manner, withdrawing it for two to three months and then restarting it if necessary.

In contrast to hydroquinone, tretinoin may be continued for maintenance treatment since there is no evidence of tolerance or increased risks with continued use. Onset or effect of tretinoin is delayed and may not occur for six months. Therefore, it should be started when hydroquinone is introduced.

However, tretinoin-induced irritation is common and an important concern, Dr. Sanchez said. To minimize the retinoid dermatitis, he uses the 0.025-percent cream preparation of tretinoin and adds a nonfluorinated corticosteroid, usually hydrocortisone, to the treatment program.

"The steroid helps reduce erythema from the topical retinoid. However, it has been reported that melasma regressed quickly, albeit temporarily, after treatment with clobetasol, which would suggest the steroid may offer some hypopigmentary action as well," he said.

Use of a higher-potency corticosteroid may be considered in pqtients not responding to hydrocortisone or as a transient measure for a few days after a possibly too aggressive peel. However, Dr. Sanchez cautioned that "patients love corticosteroids" and they must be monitored for overuse.

"These individuals may have used a corticosteroid for treatment of contact dermatitis. After seeing the effect it can have for that problem, they may think it will be helpful for reducing other types of pigmentation as well," he said.

Although hydroquinone, tretinoin, and the corticosteroid can be mixed together in an extemporaneously compunded preparation, Dr. Sanchez said it may be best to have the patients apply the agents separately at first.

"I will instruct the patients to use the hydroquinone in the morning, the steroid in the afternoon, and tretinoin at night. Although this is swomewhat inconvenient, it makes it easier to identify the culprit if the patient develops a problem with tolerability," he said.

Dr. Sanchez supplements this daily treatment with glycolic acid peels administered every two to four weeks, which can significantly speed resolution. To minimize the adverse pigmentary effects of peel-induced irritation in these darker-skinned patients, he will begin with a 20-percent concentration of glycolic acid. If the patient tolerates this regimen, he may increase the glycolic acid concentration to 35 percent, and he will use trichloroacetic acid, beginning with 15 percent and going up to 25 percent, to treat pigmented areas resistant to glycolic acid.

Other Treatment Avenues to Pursue

Azelaic acid (Azelex) also has a role in the management of melasma. Offering a mechanism of action different from that of hydroquinone, azelaic acid can be used as a substitute agent in patients who cannot tolerate hydroquinone, for maintenance treatment after hydroquinone is withdrawn, or even in combination with hydroquinone, tretinoin, and hydrocortisone as needed.

Although lasers can be used for treating melasma, Dr. Sanchez cautions against this practice.

"There have been some reports that laser treatment can reduce pigmentation in patients with melasma, but not all patients will improve. Furthermore, there is a particular risk of inducing pigmentation in these darker-skinned Hispanic patients," he said.

Sun protection is also an essential component of melasma management. These patients should be instructed to use a broad-spectrum sunscreen that offers UVA und UVB protection with a minimum SPF of 30 and to apply it at least every 2 hours when outdoors. In addition, a careful drug history should be taken, including identification of any prescription, OTC, and herbal medicines being used - as some of these agents may be associated with phototoxic reactions that can exacerbate melasma.

Dr. Sanchez said in his initial assessment of melasma patients he will always examine the skin with a Wood's light to differentiate between dermal and epidermal changes.

"Dermal pigmentation does not respond that well to the treatment modalities we have available, so hopefully the patient will have enough of an epidermal component that some improvement can be achieved. However, considering the cost and duration of therapy for melasma, it is important that we develop some prognosis for these individuals from the outset by identifying if their disease may be difficult to treat," he said.