A double-blind randomized trial of 5% ascorbic acid vs. 4% hydroquinone in melasma

Background Melasma is an acquired treatment-resistant hyperpigmentation of the skin. Methods Sixteen women with idiopathic melasma were included in our trial. After randomization by another clinician, they were instructed to use, at night, 5% ascorbic acid cream on one side of the face and 4% hydroquinone cream on the other side, for 16 weeks. Sunscreen was applied daily throughout the period of observation. They were evaluated every month by colorimetry, digital photography, and regular color slides. Subjective evaluation by each patient was also taken into account. Results The best subjective improvement was observed on the hydroquinone side with 93% good and excellent results, compared with 62.5% on the ascorbic acid side (P < 0.05); however, colorimetric measures showed no statistical differences. Side-effects were present in 68.7% (11/16) with hydroquinone vs. 6.2% (1/16) with ascorbic acid. Conclusion Although hydroquinone showed a better response, ascorbic acid may play a role in the therapy of melasma as it is almost devoid of side-effects; it could be used alone or in combination therapy.