SANTA MONICA, CALIF. The key to treating pigmentary disorders is making an accurate diagnosis using a Wood's lamp and classifying the patient's condition, according to Dr. Anand Ganesan.
"One of the things that is easy to learn but is easily forgotten is how to really prepare your patients when they first walk in the door, and for you to assess how well they are going to respond to the treatments that you are offering," said Dr. Ganesan, who is a professor of dermatology at the University of California, Irvine.
Dr. Ganesan discussed the etiology, diagnosis, and treatment of pigmentary disorders, as well as the triaging of patients with these conditions, at a cosmetic dermatology seminar sponsored by Skin Disease Education Foundation (SDEF).
Melasma
About 75% of melasma patients are female, and the condition is common in darker-skinned patients, he said. The exact cause of melasma is unknown, but triggers may include sun exposure, family history, phenytoin exposure, oral contraceptives, pregnancy, and increased estrogen.
The Wood's lamp is used to determine the classification of melasma: epidermal, dermal, or mixed. "If you can categorize your patients, you can actually predict very nicely how well they are going to respond to your treatment," he said.
In white and Hispanic patients, melasma appears as a reflected darker image. In patients with skin types V or VI the color will appear a little reddish, but a change can be seen over the pigmented area.
Melasma that has an epidermal component will respond well to almost any treatment. Dermal melasma tends to respond better to laser therapies. Darker-skinned patients will respond best to hydroquinone, while lighter skin responds best to peels and lasers.
Patients with melasma need to use a broad-spectrum sunscreen (UVA and UVB coverage with an SPF of 30 or more) every day, regardless of sun exposure, because fluorescent lighting emits some UVA rays, said Dr. Ganesan.
Birth control pills, cosmetic products, and phototoxic drugs should be discontinued if they appear to help cause the melasma.
Combining topical products is more effective than using tretinoin, hydroquinone, or steroids alone, he said, adding that it is important to balance an agent's potential for irritation with its strength because increased inflammation will result in poor clinical outcomes.
For patients who cannot tolerate hydroquinone, there are some less effective alternatives: kojic acid, which can be more irritating than hydroquinone; azelaic acid; mequinol, which has been shown to have some depigmenting activity and is less effective than hydroquinone; arbutin, which is a botanically related compound that can cause depigmentation; and licorice extract, available in Ayurvedic and other commercial preparations.
Chemical peels are not effective as single agents for treating melasma but may be slightly synergistic when used with hydroquinone. Peels are operator dependent, said Dr. Ganesan, so if the clinician has extensive clinical experience with them they may be a treatment option.
Studies suggest that the Q-switched Nd:YAG and ruby lasers, used in conjunction with hydroquinone, may be effective in treating dermal or mixed melasma. Positive results also have been seen with Fraxel lasers.
Vitiligo
The underlying factor thought to cause vitiligo is melanocyte susceptibility to destruction.
As with melasma, the diagnosis should be made with a Wood's lamp, which can distinguish vitiligo from other hypopigmenting conditions. Biopsy, along with Fontana-Masson staining, can be helpful to determine if melanocytes are present, Dr. Ganesan said.
There are two types of vitiligo: segmental (unresponsive to light therapy) and generalized (responsive to light therapy). Treatment options include photo therapy, lasers, surgery, and topical solutions. Given the safety and tolerability of narrow-band UVB, it is favored over treatment with PUVA.
A 380-nm excimer laser can be used to treat small surface areas, such as those on the face, but is less effective on the hands. An excimer laser should be used aggressively with dose escalation for best treatment results, Dr. Ganesan said. Because aggressive dosing regimens can lead to increased burning, it is best for treating localized areas and for patients who seek rapid improvement.
Although the excimer laser should be avoided when treating underarms, the device works well on the eyelids, he continued. It produces less response on the hands and feet but is an option if narrow-band UVB has failed.
Surgical options for treating vitiligo include punch grafting and suction blister grafting. Punch grafting has been found very effective for treating nonactive segmental lesions. A side effect of punch grafting is cobblestoning, which can diminish over time.
Dr. Ganesan disclosed having no conflicts related to his presentation.