Analytic assessment under ultraviolet light of actinic lentigines under bleaching treatment

Actinic (solar) lentigines are melanotic tumors frequently developed during photoaging on the dorsum of the hands. Bleaching (whitening) agents are commonly offered to fade their darker aspect. In general, regular colorimetric methods show poor sensitivity to disclose any bleaching effect.

The present randomized controlled study on 24 women was designed to objectively assess the clinical efficacy of a combination of bleaching agents on actinic lentigines. In the endeavor of improving sensitivity, the ultraviolet light-enhanced visualization (ULEV) method was used to derive analytical measurements of lentigo areas and darkness. The test product was a commercially available formulation associating glycolic acid, kojic acid, lipohydroxyacid, and a Vitreoscilla extract. The Analysis® Olympus and Adobe Photoshop® quantitative methods were applied to the ULEV pictures.

Data indicated a rapid bleaching effect arising as early as after 1 month of daily applications. The effect progressively increased over 3 months of therapy.

The presently described analytical method appears to be sensitive to document some bleaching effects on actinic lentigines.