Treatment of café-au-lait macules with picosecond and nanosecond 1064-nm nd: YAG laser: a retrospective study.

To investigate the efficacy and safety of picosecond (PS) and nanosecond (NS) 1064-nm neodymium-doped yttrium aluminum garnet (Nd: YAG) laser in treating Café-au-lait macules (CALMs). We retrospectively analyzed the medical records of patients with CALMs, who were treated with PS or NS 1064-nm lasers from January 2020 to January 2022. The efficacy was determined based on the before and after pictures by two independent investigators. The incidence of adverse events and recurrence were explored after treatments. A total of 116 patients (83 in the PS group and 33 in the NS group) were recruited. For subjects in the PS group, after 1-9 sessions, the lesion clearance was poor in 15 patients (18.1%), fair in 29 (34.9%), good in 14 (16.9%), and excellent in 25 (30.1%). In the NS group, after 1-7 sessions, the lesion clearance was poor, fair, good, and excellent in 7 (21.2%), 8 (24.2%), 13 (39.4%), and 5 (15.2%) patients, respectively. There was no statistically significant difference in efficacy between the two lasers (p > 0.05). The incidence of complications (hyperpigmentation, hypopigmentation) in the PS group (16.9%) was numerically lower than in the NS group (24.2%) (p = 0.136). Among patients who responded well to the treatment, 10.3% of patients in the PS group experienced relapse, compared with 22.2% in the NS group (p = 0.926). The PS 1064-nm laser provided comparable efficacy and potentially fewer complications compared with the NS laser in treating CALMs.