A pilot study using reflectance confocal microscopy (RCM) in the assessment of a novel formulation for the treatment...

Melasma is a common pigmentary disorder caused by abnormal melanin deposits within the skin. Hydroquinone (HQ) is presently the most popular depigmenting agent, however the treatment of melasma remains unsatisfactory, resulting in a need to evaluate new depigmenting agents.

The objective of this study was to assess, using standard methods and a novel technique, in vivo Reflectance Confocal Microscopy (RCM), the efficacy and safety of a new non-HQ bleaching agent Dermamelan® (Mesoestetic, Barcelona, Spain) in the treatment of melasma.

Ten women with melasma were enrolled in an open-label trial lasting four months. Patients were of Fitzpatrick skin types II-IV. A non-HQ depigmenting agent (Dermamelan) was applied once-daily for three months. Melasma Area and Severity Indices (MASI) were measured. Standard and UV-light photographs were taken and in vivo RCM, which detects pigmentary changes at a cellular level, was done. Evaluations were performed before treatment, on the first, second and third month of treatment and one month after treatment. Upon cessation of the trial, patients completed a questionnaire regarding efficacy and tolerance.

At baseline, RCM detected hyperpigmented keratinocytes in all patients, dendritic cells in 2/10 patients, and melanophages in 2/10 patients. Based on the MASI score, Dermamelan treatment improved melasma by 50 percent. This was confirmed by standard and UV-light photography. Maximum therapeutic effect was usually reached by one month of treatment and was maintained at one month following its completion. Interestingly Dermamelan treatment also induced a statistically significant decrease of pigmented epidermal keratinocytes as detected by RCM. Patients with melanophages on RCM at baseline had a poorer outcome, but not those with dendritic cells. Mild irritation was the only adverse event observed during treatment. The majority of patients were satisfied with the result.

This study suggests that Dermamelan produces significant rapid improvement of melasma at a clinical and cellular level and demonstrates the potential of RCM to monitor and possibly predict efficacy of a new depigmenting agent in the treatment of melasma.