Comparative study of ablative fractional photothermolysis versus topical retinoid cream in the treatment of idiopathic guttate hypomelanosis

Background: Despite various treatments attempts, no prospective studies have compared the different therapeutic modalities for treatment of idiopathic guttate hypomelanosis (IGH). This study aimed to compare the efficacy of CO2 fractional laser (CO & FL), Er:YAG fractional laser (EYFL), and 0.025% topical tretinoin for treating IGH. Materials and Methods: A total of 122 lesions were analyzed from 18 patients (mean age, 70.00 +/- 20.00 years). Treatment outcome evaluations included the visual analog scale (VAS) to assess lesion severity, investigator's global assessment (IGA) to assess the extent of improvement, and patient's satisfaction score (PSS). Results: Among the 122 lesions, 42, 40, and 40 were assigned to the CO & FL, EYFL, and topical tretinoin treatment groups, respectively. The VAS score was significantly improved after the second treatment. CO & FL and EYFL therapy had superior treatment efficacy compared to topical tretinoin (p < 0.01 in VAS, IGA, and PSS). There was no significant difference between the two types of fractional lasers. Conclusions: Ablative fractional laser (AFL) was an effective treatment with a relatively short treatment time without serious adverse events. We recommended AFL to treat IGH as an active treatment strategy.