Efficacy of cysteamine cream in the treatment of epidermal melasma, evaluating by Dermacatch as a new measurement method: a randomized double blind placebo controlled study.

BACKGROUND

Melasma is a difficult-to-treat hyperpigmentary disorder. Very few studies have been performed regarding the efficacy of cysteamine in the treatment of melasma.

OBJECTIVE

To determine the efficacy of cysteamine cream in the treatment of patients with epidermal melasma using Dermacatch as a more accurate skin colorimetric measurement tool.

METHODS

Participating patients (n = 40) received either placebo (n = 20) or cysteamine cream (n = 20) in a double-blind placebo controlled study. Cysteamine cream or placebo was applied on the lesions once a day at bedtime throughout the four-month study period. Treatment efficacy was determined through Dermacatch and Mexameter skin colorimetry, MASI scores, Investigator Global Assessments (IGAs), and patient questionnaires, all performed at baseline, 2-month, and 4-month examinations.

RESULTS

Prior to the start of the protocol, the mean difference between pigmented and normal skin was calculated for cysteamine and placebo groups using both Dermacatch (72.3 ± 27.8 and 52.9 ± 16.4, respectively) and Mexameter (93.6 ± 42.6 and 65.4 ± 22.6, respectively). At 2 months, the mean differences were 38.1 ± 15.3 (Dermacatch) and 49.9 ± 19 (Mexameter) in the cysteamine group and 64.9 ± 25.3 (Dermacatch) and 68 ± 26.2 (Mexameter) in the placebo group. At 4 months, the mean differences were 23.8 ± 12.9 (Dermacatch) and 35.5 ± 16.1 (Mexameter) in the cysteamine group, and 50 ± 18 (Dermacatch) and 51.2 ± 16.8 (Mexameter) in the placebo group. Statistically significant differences were found between the cysteamine and placebo group outcomes at both time points (p = .01, p = .02). At the end of the treatment period, MASI scores were significantly lower in the cysteamine group versus placebo (8.03 ± 5.2 vs. 12.2 ± 7.4, p = .04). IGA scores and patient viewpoints indicated significant efficacy of cysteamine cream versus placebo.

CONCLUSION

Cysteamine cream showed significant efficacy in decreasing melanin content of the lesions, as established by Dermacatch as a new measuring method.