Instrumental analysis of the pattern of improvement and that of recurrence of melasma in Thai females treated with Kligman–Willis triple combination therapy: confirmation by using its two different formulae

Background: Melasma is common among females. At present, its most reliable topical treatment is the Kligman–Willis formula. Objectives: To evaluate objectively the pattern of pigmentation improvement and recurrence. Methods: Thirty‐four Thai females with melasma showing similar lesions on both cheeks were randomly assigned to 8‐week daily treatment with either one of two different versions of the formula together with strict sun protection. They were objectively evaluated instrumentally with a Mexameter^® every 2 weeks, and were followed up for the subsequent 40 weeks. Results: Thirty of 34 subjects who completed their 8‐week treatment displayed a similar improvement pattern with either formulae. All expressed satisfaction with the results of the treatment. Instrumental evaluation detected that the pigmentation reached a nadir after 6 weeks, regardless of the formulae. Twenty‐one subjects, who were further followed up, exhibited mild relapse within 2 months after finishing the treatment. Yet, their pigmentation levels remained significantly lower than those before treatment. Both formulae increased transepidermal water loss and skin surface hydration during the treatment period. Conclusion: Melasma in Thai females responded well to the Kligman–Willis formula. A relapse that was detected with the instrumental measurement after treatment discontinuation suggests the necessity to continue even intermittent treatment after attaining therapeutic success.