Evaluation of efficacy of a Chinese herbal mask in the treatment of melanized-type melasma by stereological measurements
Objective To evaluate the efficacy and safety of a Chinese herbal mask in the treatment of melanized-type melasma by stereological measurements.Methods A randomized,controlled,evaluator-and statistician-blind clinical study was conducted.A total of 116 patients with melasma who met the inclusion and exclusion criteria were selected and equally divided into two groups by using a random number table method,with 58 patients in each group.The treatment group received topical treatment with a Chinese herbal mask once a night,while the control group received topical hydroquinone cream in the morning and evening twice daily.The course of treatment lasted 12 weeks,with follow-ups every 4 weeks,and an additional follow-up was performed 12 weeks after discontinuation of treatment.A facial image analyzer and a reflectance confocal microscopy(RCM)were used to collect images before and after treatment.Melasma area and severity index(MASI)scores and RCM scores served as outcome measures,and stereological measurement methods were employed to compare scores before and after treatment;response rates and recurrence rates were calculated,and adverse reactions were observed and recorded.Statistical analyses were performed using the chi-square test and t test.Results A total of 54 patients in the treatment group and 47 patients in the control group completed the study.After 4-and 8-week treatment,there were no significant differences in MASI scores or RCM scores between the two groups(all P>0.05);after 12-week treatment,the MASI scores and RCM scores were significantly lower in the treatment group(2.91±1.16,5.48±1.60,respectively)than in the control group(3.99±2.03,6.66±1.88,t=-3.32,-3.37,respectively,both P<0.01).After the end of treatment,there was no significant difference in the response rate between the treatment group(44/54,81.5%)and the control group(34/47,72.3%;x2=0.12,P>0.05).Twelve weeks after discontinuation of treatment,2 patients(3.7%)relapsed in the treatment group,while 15(31.9%)relapsed in the control group,showing a significant difference in recurrence rates between the two groups(x2=12.34,P<0.01).Adverse reactions occurred in 2 patients(3.7%)in the treatment group and 6(11.5%)in the control group,and there was no significant difference in the incidence of adverse reactions between the two groups(x2=1.34,P>0.05).Conclusions The Chinese herbal mask was safe and effective in the treatment of melanized-type melasma.The application of the facial image analyzer and RCM technology in combination with stereological measurement methods has certain value in reducing the subjectivity in efficacy evaluation for melasma.