Ochronosis

PHOENIX, ARIZ. -- Although melasma may be considered medically benign, the condition can be psychologically malignant, and practitioners need to take action in identifying and treating the condition in order to decrease patient anxiety, Dr. A. Paul Kelly said at a clinical dermatology conference sponsored by Medicis.

Even though the condition occurs in as many as 50%-70% of pregnant women in the United States, misunderstandings may explain why it's mainly dermatologists--and rarely ob.gyns.--who are called upon to treat the condition.

"Only about 2% of ob.gyns. typically treat melasma," said Dr. Kelly, chief of the division of dermatology at Martin Luther King/Charles R. Drew Medical Center in Los Angeles.

"Some women report being told the condition is simply a 'souvenir of being pregnant,' that they can just cover it up with makeup, or that nothing can be done," he said.

In addition to pregnancy, in which melasma typically occurs in the second or third trimester, the condition can also result from oral contraceptive use, and it is more common and distressing in Fitzpatrick skin types III and IV.

Etiology factors for melasma include genetic factors and sun exposure, and clinical patterns include centrofacial (63%), malar (21%), and mandibular (16%).

The condition can take a freckle-like pattern. "The freckle-like pattern usually is not described in textbooks, but it will typically look like patients are developing freckles. You won't see a confluent lesion, but small macules that become confluent," said Dr. Kelly.

The most common and treatable type of melasma is the epidermal form, making up 70%-94% of cases and consisting of brown hyperpigmented macules. In pregnant women, the symptoms will often fade after delivery and then darken with subsequent pregnancies, said Dr. Kelly.

If using 4% hydroquinone to treat melasma, results can take up to 20 weeks. Lower concentrations are less effective, said Dr. Kelly.

"The 2% OTC hydroquinones are relatively ineffective," he said. "You can increase the strength up to 10%, but after that it usually breaks down."

Dr. Kelly emphasized that hydroquinone should not be used in pregnant women.

A fair number of people are allergic to the drug, and Dr. Kelly recommended doing a patch test on patients before use. While exogenous ochronosis is seen in about 42% of South African women and 15% of South African men using hydroquinone, the condition is very rare in the United States. Dr. Kelly said he has only seen one case.

Nonphenolic compounds that have been used to treat melasma include corticosteroids, tretinoin, kojic acid, licorice extract, blueberry, mulberry, nicotinic acid, and vitamin D. However, Dr. Kelly said the compounds don't show strong signs of working any better than hydroquinone.

Chemical peels have been used, including 30%-35% trichloroacetic acid peels plus hydroquinone; 70% neutralized glycolic acid; and 48% free glycolic acid plus 30% trichloroacetic acid. But Dr. Kelly warned that instead of lightening the areas, chemical peels can sometimes trigger postinflammatory hyperpigmentation. Critical to any kind of successful treatment is patient education, and a key component of that is to avoid the sun, said Dr. Kelly. It's also important to explain to patients that their pigmentation cells remain dysfunctional after the precipitating event. Patients must understand that they remain at risk and need to take precautions or risk developing more problems later.

BY NANCY A. MELVILLE

Contributing Writer

COPYRIGHT 2004 International Medical News Group
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