In a small pilot study, Rokhsar and Fitzpatrick report results from a series of 10 patients with melasma treated with fractional photothermolysis. They enrolled 10 female patients (average age 45 years; Fitzpatrick Skin Phototypes [SPT] III-V) with melasma that had proven refractory to prior treatments, including 1 or more of the following: topical hydroquinone, retinoic acid, chemical peels, microdermabrasions, intense pulsed light (IPL), and laser treatments (erbium, carbon dioxide, alexandrite). These subjects received Fraxel laser treatment (4-6 treatment sessions, spaced 1-2 weeks apart) at energies of 6-12 J/cm2 per microthermal zone (mctz) and density settings of 3500 mctz/cm2. All patients received topical anesthesia (30% lidocaine for 1 hour prior to each treatment) supplemented with nerve blocks as needed. Patients were instructed not to use other melasma therapies during the laser treatment period. Outcome measures included physician evaluation of before-and-after photographs for percentage of pigment lightening and patient assessment.

All treatments were tolerated well, with minimal downtime. Local treatment effects were limited primarily to erythema, with a few patients developing short-lived small linear abrasions or crusting. No patients developed scarring or prolonged hyper- or hypopigmentation, although 1 Hispanic patient (SPT V) developed temporary posttreatment hyperpigmentation. Treatment-associated discomfort was tolerable but significant, with patients reporting an average pain score of 6.3 on a 10-point scale despite the use of topical anesthesia.

By physician assessment, 60% of the patients showed 75% to 100% clearing following the Fraxel treatment series. This agreed well with patient self-assessment of 75% to 100% clearing (50% of patients). One Asian patient with apparent dermal melasma on her bilateral cheeks showed complete clearance of hyperpigmentation. A majority of patients reported being very satisfied (60%) or slightly satisfied (30%) with their treatment response. Although most treatments were facial, 2 patients also received treatment of neck melasma with no complications.

Comment

Fractional photothermolysis is an intriguing new laser technology that uses focused infrared laser energy (1550 nm) to create a network of microscopic intradermal zones of thermal damage in the dermis and overlying epidermis with islands of spared, normal tissue.[1] Ablative laser skin resurfacing (LSR) of melasma can yield some clinical improvement, but this is limited by adverse sequelae, including prolonged wound healing and the potential for postinflammatory hyperpigmentation.[2] Fitzpatrick and Rokhsar postulated that fractional photothermolysis, on the basis of its mechanism of action, might be an effective treatment of melasma, producing pigment fading without the unwanted side effects seen following ablative LSR. Indeed, the results of their small pilot study suggest that fractional photothermolysis is a safe, tolerable, and potentially highly effective treatment for melasma.

Impressive features of Fraxel treatment for melasma include its high safety profile, even in darker skin phototypes, and apparent clinical efficacy, even in cases of previously treatment-refractory melasma. Treatment limitations include expense and treatment-associated discomfort, even when using topical anesthesia. The main limitations of the above study are the lack of clinician blinding during photographic evaluation (before vs after pictures) and lack of long-term follow-up for pigment recurrence or delayed adverse sequelae such as late-onset hypopigmentation. Future studies should attempt to stratify melasma by subtype (epidermal, dermal, mixed pattern) prior to treatment, and should include long-term follow-up data, because the clinical improvements seen after melasma therapies are notoriously short-lived.