Analytic quantification of the bleaching effect of a 4-hydroxyanisole-tretinoin combination on actinic lentigines.

BACKGROUND

Solar lentigines represent a common feature of photoaging, particularly on the back of the hands. Bleaching agents are usually proposed to lighten the shade of the lesions.

METHODS

The study was randomized and designed to assess the effect of a bleaching solution containing 2% mequinol (4-hydroxyanisole, 4HA) and 0.01% tretinoin (Solagé). The formulation was applied twice daily for 3 months on solar lentigines present on the back of one hand. The lesions on the other hand were treated with the ethyl alcohol vehicle which served as a control. Clinical diagnosis was confirmed using dermoscopy. In addition, objective measurements of the hypermelanosis were performed at 1-month intervals during and after treatment. Clinical assessments were used as well as narrow-band reflectance spectrophotometry, image analysis of video-recorded ultraviolet light-enhanced visualization (ULEV method) and photodensitometry of the corneomelametry test.

RESULTS

The multipronged assessment of the lesional color demonstrated a significant lightening effect of the 4HA/tretinoin solution. This was demonstrated after 2 months of treatment and was maintained at least 2 months after stopping treatment.

CONCLUSION

Both the visual ratings and the objective bioinstrumental methods indicate the rapid lightening effect of the 4HA/tretinoin formulation. After stopping treatment, the rate of repigmentation appeared to have slowed compared to the depigmentation phase.